Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: Biscuit on December 18, 2006, 09:52:59 pm
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Hi, New to this Forum, need a bit of help here.
As I was having so much trouble trying to start my SC 61 last time at the lake, infact I gave up and came home, I thought before the next time the lake was booked I would try and run it in at home, got a pump to cool the engine new starter and battery. Got it started but so rich so leaned it out on the top end but then when I shut the throttle it went all lean and started reving its head off! no mater what I did the same thing would happen, been in touch with Dave a Prestwich he said the low running mixture screw should be screwed nearly all the way out and the top end only 1 turn out. Well I was going to try this but noticed today that the motor had lost compression, stripped the motor and found one part of the piston had seized only a small mark but thats all it takes to lose the seal. Could this of happened because the motor was over cooled with the pump, its very powerfull , maybe the piston an liner could not expand so it just nipped up for a second? was thinking of putting it back as its still got a good pop! but will not hold compression at TDC. So lost another Sunday, will I ever get this boat to run? its was all brand new really thinking of throwing in the towel and going back to my helicopters. So can anybody help or give me some advice as I am new to this boating lark.
Thanks.
Steve.
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Hi Steve,
Been there, done that! :-\
1, How old is the engine?
2, Did it run Ok from about 1/3 throttle and up when it was running?
Matrin
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Hi, the engine was brand new, the boat and the engine were part of an unfinished project, the engine always seemed a bit rough when you turned it over and there were signs of rust on the plug even though I know the engine had never been run. Since stripping it down I have replaced the rear bearing as it was rough and rusty, it had been kept in a garage for 2 years so rust might of built up then as there was no oil in the motor. Like I said the carburation was just all over the place you opened the throttle it almost stopped so rich, yet even like this it would scream when you closed the throttle, you just looked at this engine carb shut reving its head off, never seen it before only way to stop it finger over the carb. Any Ideas? and have I killed it trying to run it in?
Cheers
Steve.
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Hi Biscuit,
We have a few of these motors at our club, and all of the new ones that belong to new members had this revving or nothing problem. I can't speak from first hand ownership of one of them, but have been using marine IC's since 1963.
The SC engine is very tight when new at the top of the stroke, which they mention in the instructions.
I have heard of people actually skimming the piston sides to remove some of the binding, which is part of the design of an ABC engine. I have an SC21, which feels so tight when turned over by hand with no plug in as if it would tear itself to pieces when running. I don't know how the con rod takes the strain.
I have an OS 32 ABC engine that does not bind at all (which would suggest clapped out), with the plug removed, so no compression to misslead, and that starts first time every time winter or summer with no problems at any rev range. I would have thought that to have lost enough compression that it is noticeable, the motor would have to be almost minus the piston. It's also strange the the motor would not throttle down. If the air intake is closed, the motor should stop no matter what the mixture setting is. I have a few motors with marks on the piston and bore, and they run with no problems. They may be down on power, I don't know, and they are only used for sport not racing boats, so a slight loss of power does not matter any way. It is also normal now days, to loosen the glow plug about half a turn, and then re tighten it as soon as the engine starts.
I would put it back in the boat, and give it another try. Whats to loose?
Regards Bob
The post above was added while I was typing my reply.
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Hi again,
Can you actually see the barrel being chocked by the air flap?
Bob
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Hi again,
Can you actually see the barrel being chocked by the air flap?
Bob
Hi Bob, thanks for the reply,
Yeah its shutting down to just leave a cap for tick over, when you start it the tickover is quite fast, but when you open the throttle you can see raw fuel spluttering out of the intake like its too rich on the top end, so you lean it out so it picks up then it wont shut down when the throttle is closed unless you put your finger over the carb intake,had to loosen the plug to turn it over, start it then tighten it again. Did the other lads with the SCs get them sorted?
Thanks
Steve, (biscuit)
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hi it sounds like the engine was either damaged or as you say rusted up and youve now probably ruined the piston and barrel if you say it was grinding?.they are tight engines and you have to loosen the plug all the time to get them to turn over.id strip it and check the piston and barrel and see if its scratched up if so it depends how bad it is as to what you can do.i bought mine off ebay for 25 quid it was quite new ,it was a plane engine and i made a cooling coil for it to put into my boat.she runs well but shes still a devil to turn over.impossible if you dont loosen the plug id say.good luck with it.they are also difficult to tune but once they are they run well .i spent a full day messing with mine to get it to run for more than two minuites now it starts first time and i agree they are powerfull motors .
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It was the rear bearing that was rough, I think due to storage in a damp garage, might do what Bob says and stick it back in. I have replaced the rear bearing and it is very smooth when you turn it over now, and still got good compression, but not as good as it was, only a little mark on the piston, but like I said before thats all it takes to lose the seal on an ABC engine. You say it took you all day to sort out your engine, did you run it in at home or at the lake? and what settings did you end up with carb wise? and is it reliable now? Any help would be most welcome.
Thanks.
Steve.
Ps trying to upload some pics of my boat but it keeps saying the files to big, always been able to upload on other sites am I doing something wrong here?
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hi sorry i cant remember the exact settings it was a guess and see as i had no book for the engine,it runs great but as it was a plane engine i tuned it on the bench ..try the factory settings if you have the book or ask dave marles who sells them for the settings.they are great engines and in my opinion better than os engines at less than half the price,they are copies of the os actually but they are better made apparently.stick with it you will get it going i couldnt fathom it but half a turn of the needles and off she went and hasnt had a problem at all since.i darent touch the needles now lol.forgot to say download microsoft image resizer its free and change pics to medium it works great.sorry i couldnt help more.by the way even with cooling if you test it out of water dont rev it too much or you will over rev the engine with no resistance on the prop and it will seize up.thats why i used the aero prop to tune it before i converted it to marine use.
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http://www.modelboatmayhem.co.uk/forum/index.php?topic=1760.msg17293#msg17293 (http://www.modelboatmayhem.co.uk/forum/index.php?topic=1760.msg17293#msg17293) should be a link back to the thread Basic Setting of SC's started by peewee.
All SC's must run on 20% oil - you did not specify your fuel or oil content. 100ml of extra oil per gallon will increase the oil content by approx. 2%
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http://www.modelboatmayhem.co.uk/forum/index.php?topic=1760.msg17293#msg17293 (http://www.modelboatmayhem.co.uk/forum/index.php?topic=1760.msg17293#msg17293) should be a link back to the thread Basic Setting of SC's started by peewee.
All SC's must run on 20% oil - you did not specify your fuel or oil content. 100ml of extra oil per gallon will increase the oil content by approx. 2%
Motor Been run on 25% Model Technics Duraglow. Thanks for the link.
Steve.
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I have read this link before, no way will my motor run at 2,1/2 turns out on the main needle, more like 1 turn with the idle needle almost out to the stop, or its just too rich on the top end. £30 for new piston and liner, might get one, but going to try it again with the old one first. Made a restrictor for the water pump so that the engine can run a bit hotter.
Thanks
Steve.
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Hi Biscuit,
Not directly linked to your running problems, but it has always amazed me how people connect some sort of water pick up to a varying length of and bore of pipe. They then run this to a varying range of motors in yes you've guessed it, a varying range of marine craft, from slow to fast. And guess what, everything always seems to work OK.
In the supper sophisticated world of fast I C boats, they do have methods of assessing the running temperature of the motor. But the sport boats just get by with what they are given. A rule of thumb I once read, suggested that after the motor had reached its running temperature, some drops of water should be splashed onto the head. The water should evaporate quickly away, but not boil off.
I use a running tank in the garden made up from a scaffold plank with a heavy duty sheet layed into it, and then filled with water. At the back end of the box, I fold the sheet back towards the front with a board over it, to keep the water in the box. The box has eight angle brackets at the ends, spaced so the sides drop in between, and eight nails just plug into pre drilled holes.
Regards Bob
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http://www.modeltechnics.com/glowfuel/duraglo.html (http://www.modeltechnics.com/glowfuel/duraglo.html) is the link to Model Technics site. Duraglo is 15% oil. You need to be PLUS 5% on Oil.
2 to 2½ turns is the starter position for running for a new engine - the final running position will be closed down from there. 1¾ turns was about the figure that I used. Run the engine HOT especially at this time of the year
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Yeah I know most engines start at 2.1/2 turns out when new, but the SC was just not going to run at this setting, wether it was because the motor was too cold I don't know. Like I said Dave at Prestwich Models said that the Idle needle is too long so you have to have it right out and then lean the top end down. There must be someone out there who has had this problem and got it sorted, my boat is back together and ready to go, just going to start it and chuck it in and see what happens, got to wait another month to book the lake.
Thanks.
Steve.
Ps managed to get some pics on.
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Hi Steve,
I had some set up problems with my SC61 when it was new, one of which was it being really tight, think they all are, made it very hard to start, but experienced some problems with carburration, mine were cured by relocating the fuel tank lower in the model.
Hope this helps.
Glenn
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Thanks Glenn,
Yeah did think about that but the tank is as low as I can get it, might be as Dave said just got to get that carb right.
Thanks.
Steve.
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steve as i said these engines just take small adjustments to get it right a slight turn one way or the other on the low end needle and the thing just wont run it will start and probably run at full tilt and then die as mine did till i got it right.can i ask what size the boat is? if its big enough pull the sc out and get a zenoa petrol engine and no problems with starting then lol
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Boat is 42" long, think you can get a Zenoa in not sure about the hight, maybe you can buy a higher hatch for it, I know what you mean got a Zenoa in my FG Buggy, its just so hassle free, and seen a lot of motors on e-bay at a good price. Cheaper than a CMB or Pico, don't know why these engines are so expensive, do you think my boat is big enough for a Zenoa??
Cheers
Biscuit
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Boat is 42" long, think you can get a Zenoa in not sure about the hight, maybe you can buy a higher hatch for it, I know what you mean got a Zenoa in my FG Buggy, its just so hassle free, and seen a lot of motors on e-bay at a good price. Cheaper than a CMB or Pico, don't know why these engines are so expensive, do you think my boat is big enough for a Zenoa??
Cheers
Biscuit
Yes i think its big enough its the same boat as this one!! yours is a bit smaller but i think the zen would fit as it fits in this cat which is 41"
http://www.radiocontrol-2005.com/tunami.htm
i think the same company makes the 41" hull too maybe if you ask them they can help you out.
]] (http://)http://www.radiocontrol-2005.com/flying%20dragon.htm yours is a bit smaller but i think the zen would fit as it fits in this cat which is 41"
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Biscuit - Have you checked your critical (tuned) length for the engine/pipe set up in your pictures?
Go to http://www.nimrifmodels.co.uk/setup.html (http://www.nimrifmodels.co.uk/setup.html) for a chart on the critical lengths of engines.
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Thanks, but I don't think that is a real tuned pipe, its called a quite pipe just got a baffle in the end with holes in it, will those diagrams and sizes work? wish I had never got this boat spent so much time on it painting and such, its going on e-bay and I will buy a ready to run that I will know will work. Think this boat was supplied with very poor exhaust and engine and hardwear for what it cost, cant see anyone getting this set up to run. Thanks anyway John,
Steve.
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where you going to get a decent rtr boat here for good money ,better to buy a hull from usa or china and that zen i showed you then you may get a boat for 400 quid .over here you will be talking £1000 with radio.dont buy one of those crap ebay gas boats unless its that arrow shark one which isnt bad for the money.the other ones you see for 200 to 300 are rubbish.im building my own from plans from ply and ill be using a 28 cc weedy engine i got off ebay for 15 quid and im putting the walbro carb on it as im told it fits.then im using a dave marles strut and a flex cable and ferrule set up to a stub shaft and a prather 275 prop all from china at half uk prices.my boat will be 48 to 54 " long and epoxy coated .with the bigger carb this motor will do over 35 maybe 40 mph with a tuned pipe and some port mods who knows maybe more.if you fancy building one of these let me know i have free plans of this boat.the yellow ones mine 36" the other one is w3bbys boat from sweden his runs a zen 260.its 48 "(http://)
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I Know what you are saying, but that boat of mine cost over £450 new, I paid £250 for it as an unfinished project, £80 to have it sprayed, £80 high power servos, plus £75 PCM rx. That is with out the flex drive cable that fell to bits and the rear bearing, and High power starter and battery, so still looking at a boat that cost me over £550 and never been in the water, and cant ever see it running. Tried again today to run it, put a restrictor in the cooling pipe hoping to keep it warmer, but just getting nowhere, carb settings just all over the place no matter what I do, still revs when you shut down and really rich on the top end oil every where! friend of mine got a proboat miss Lumar pullstart runs really well and no fuss, £300 and its fiberglass. So if you See my boat on e-bay give it a miss, I have had enough.
Thanks for the reply
Biscuit
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the miss lumar is a pile of crap!!!!sorry to be so blunt but there you have the truth ,keep trying your engine will run just stick with it .ill tell you what even if you have to buy another engine it will run better than the miss lumar boat and id say twice if not 3 times as fast.if you cant get the engine running best thing id say is sell it and buy another one maybe a different type ? os are good engines if a little more expensive.is there really noone who you can get to help you out? no clube nearbye?have you emailed dave marles? he knows all there is to know about boats.5 times world champ and he sells the sc range.maybe send the engine to him let him see if he can get it going?.
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Hi Biscuit,
Don't buy a ready to run, especially if it's not fiberglass, you will be disapointed. The styrene hulls fall to pieces.
The Wicked Angel, test run for a well known mag, started to crack up during the first test runs.
Stick with what you have got, it will be worth it in the end.
The SC engines do work, it's just a matter of sorting it out.
Most I C's can have problems at the start. I had an OS that nearly drove me mad, but now it's sorted, it starts first time every time. Other club members with electric starters look on in wonder as it starts first time every time, with a pull cord, while they spend ages with electric starters.
Remember, no pain no gain.
Bob
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Yeah I know what you are saying, but that Miss Lumar is fiberglass and to me goes well, cant see my boat being that fast with that engine, not going to spend any more money on it, been in touch with Dave a few times, getting no where. The hull should get a fair price on -bay, would not sell it with that engine, take the radio out as well, will lose money but I can see myself better off with something else, any Idea what the hull is worth with the hardwear?? thanks
Biscuit.
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Re: engine problems.
You could try getting in touch with Just Engines - http://www.justengines.co.uk/ (http://www.justengines.co.uk/)
- what they don't know about engines, isn't worth knowing! Don't know what they might charge but it's worth an email or phone call.
Martin.
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Yeah I know what you are saying, but that Miss Lumar is fiberglass and to me goes well, cant see my boat being that fast with that engine, not going to spend any more money on it, been in touch with Dave a few times, getting no where. The hull should get a fair price on -bay, would not sell it with that engine, take the radio out as well, will lose money but I can see myself better off with something else, any Idea what the hull is worth with the hardwear?? thanks
Biscuit.
mate you are so wrong i promise you your boat will fly past that pile of crap once you get your engine sorted ,stick with it you have too much time and money in it to give up now.i have not seen one good thread on rcu about the miss lumar or budweiser boat as they are the same in different colours.the v will handle great in chop when that lumar will be either sat on the bank cos hes too scared to drive it or upside down in the middle of the lake .for starters yours is 11cc his is most likely a small pull start of arround 15 to 20 size? 3to 4 cc i reckon.even witht he same engine yours is a proven hull its a very fast hull capable of 60 mph with the right engine.dont give up on it now.as said the rtr boats available over here are a load of crap ,the only way to get a good boat together over here is buy all the bits from the usa that way you get quality at half the price as here.your boat however is a good one all you need is help to get the engine sorted.if you want to throw away all your good work and money and buy a cheap hunk of junk then by all means get rid and buy that lumar junk.thats my honest opinion i hope your listening but i doubt it ,someone will get a good boat on ebay by the sounds of it i only hope they dont turn up at the lake while your running your miss lumar (junk) cos they will leave you in theire wake ;).
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OK Martno 1 fan, seems you don't like that miss Lumar then? maybe I should take a step back and do something else for a while, but you know what its like when you keep trying to sort something out and you are getting nowhere, sold one of my helicopters yesterday so thought I could sell the boat as well and start again, with something else.
Atb
Biscuit.
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OK Martno 1 fan, seems you don't like that miss Lumar then? maybe I should take a step back and do something else for a while, but you know what its like when you keep trying to sort something out and you are getting nowhere, sold one of my helicopters yesterday so thought I could sell the boat as well and start again, with something else.
Atb
Biscuit.
hi mate sorry if i went off on one i just dont want to see you waste what looks like a good boat you have there ,try posting on that other forum they will help you there are more people on there who know about ic engines than here ,sorry martin but thats just true!!.like ive said getting the set up of the engine is the key here ill go check my needle settings and see if i can help.ill screw them in and check the amount of turns needed that should give you a starting point as my engine runs well.
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right i checked my engine and the main needle is exactly 2 1/2 turns out do that and leave it there dont move it !!.now screw the other one all the way in not too tight then when it stops back it off exactly 4 turns.now try it and it should fire up and run perfectly if it doesnt i cant help.all i do know is its allways the low end needle thats the problem a slight turn this way or that and she will scream and die or not fire at all like mine did.give it a try and i hope she works for you she will certainly run well on that engine when you get her running im sure .these engines arent fast compaired to other engines of the same size though as the marine motors are the same as the aero versions hence the reason they are for sports use only.a bit like the older merc engines from years ago they just stuck a cooling head on an aero engine.nowadays most manufacturers make propper marine engines with the rpm to match.anyway good luck with it and keep us posted.
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heres another tip if she wont run!!,close the low needle and connect some tubing to the carb nipple and blow into it as you blow open the low needle till you hear a hissing sound and stop .this is tha basic setting then go from there adjusting as you go with the engine running.
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..... "£80 to have it sprayed" .....
Eighty squids to have a model boat painted???!!!
JEEEEEZZZUUS!
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..... "£80 to have it sprayed" .....
Eighty squids to have a model boat painted???!!!
JEEEEEZZZUUS!
lol no doubt he wanted a nice finnish ,thats pretty cheap if you ask me for a proffesional paint job!!.mind you id rather buy the paint and a spray gun and do it myself lol.i wonder if he got his engine sorted yet?.i think when he does he will be surprised how fast that boat is ive seen a cpl of them run and they are fast hulls ,really fast with the right engine.
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Hi Martno1fan,
Guess I will never find out, stripped the boat out today to sell it, motor is scrap, going to use the radio in something else, hope to get some money back on the hull, looks nice so you never know, had an e-mail from someone called John kind of saying the thread is getting out of hand? so this will be my last posting thanks for trying to help me out, should of done my home work before getting into boats.
Steve.
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who was it said this thread is getting out of hand give me his name ill be having a word with him!!in what way is the thread getting out of hand may i ask who ever you are as your obviously reading this ? we are all here trying to help a fellow out!!! .its a shame you gave up on her mate i may know someone wo might be interested in the hull send me a pm wih what you have in mind for her and ill let him know.if you want you can send me that motor and ill see if i can get her going for you then ill send it back to you hopefully in working order!!.ill do it for free and hopefully youll have a good engine to do whatever you want with.
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Hi Biscuit,
I was going to offer to set the engine up for you, but martno1fan beat me too it. No matter, as long as someone does it. I thought the thread was going ok so I also don't understand why someone should suggest ending it.
What does Mayhem have to say?
Perhaps he is going to make a reduced offer for your set up!
Bob
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i think hes selling the boat now !!,hes taken the engine out and unfortunately hes moving onto trucks :) seems a shame as he has a nice boat there and im sure with a bit of tinkering the engine will kick into life.i too was a bit bemused why anyone would email him saying the thread was getting out of line? .some people ehh!! ::)
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Hi Biscuit,
Don't give up now, you are nearly there, nice looking boat, minor engine prob. to sort. Send the motor to Mart or one of the other guys to get running, can't be that much wrong.
Tell whoever told you the thread was too long to wind their neck in, in fact, I just did, hey ho.
If serious about giving in drop me a PM and I may make you an offer for the hull, quite tidy looking.
Glenn
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Hi Glen i think its too late He sent me a pm saying hed stripped the engine out and its scrapped dont know if he meant hed binned it or just thrown it to one side.I agree its a shame as he obviously put a lot of work and some pride into putting it together and to give up now is such a pitty.I hope he changes his mind when hes had time to think .Im no expert with engines but i sorted my sc out just tinkering and got a few tips off another site from guys and it did help me a lot.Im moving on to gas now as its carrying the starter and battery round the place that gets to me id rather just turn up with my boat and some fuel and go !!.ill be putting a build thread in here soon as im scratch building a gas boat from free plans i have ,im powering her with a strimmer motor 28 cc i got for £15 brand new,with a walb carb fitted and a tuned exhaust i shoul see a decent improvement from it.the walb carbs fit ,i know a guy who has the same engine.also a friend of mine who mods bikes is going to port it for me at some point.
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Should be fun. I got a tuned 26cc Zenoah motor off Dave Marles in my 55" Miami, that goes well. Got a tuned pipe on and surface drive.
Yours should be a hoot.
Look forward to following the threads of the build.
Good luck.
Happy New Year. (To Everyone who reads this)
Glenn
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hi mate you cant do better than one of daves engines have you seen the new zen 7? i have a video of it running in the panther ill post the link soon for you.i wish i could afford a zen !! maybe in the summer ill swap the weedy for a zen wife permitting lol.
mart
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Hi Mart,
sure have, that's what I run in my Miami!!
It's a good motor, so far reliable, easy to start and no complaints so far. Likes to rev a lot mind..... :o
Probably should not have said that should I? Kiss of death and all that..
Currently running a BH Hanson pipe from the States which works OK but is a bit noisy, got a Prestwich one to try out when I can get round to it. What strimmer motor did you get? Is it a Zenoah? Had a few problems with mine trying to get a good throttle connection, BH Hanson to the rescue agin though. Have fun.
Glenn
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you luccky swine!! bet that cost you an arm and a leg lol,ive had numerous arguments on that other site over that motor the yanks dont like someone claiming 7.3 hp for a zen lol.i think the dave marles pipe will be very quiet compaired to the hanson one.my motor is not a zen its a sovereign ,they dont even make em dont know who does either but i do know the walb carbs are a straight fit and so is the header and pipes too so should be ok.starts easy im sure as it is it will be ok for my son to play with then ill get my freind to mod the other one as i got two for 35 quid ;D never been run either,the boat is the gas mono from plans thats been floating around the net for ages.i built a smaller one for nitro and its a nice boat if a little low in the water so ill be raising the sides a bit for this one.once we get bored of the weedy engine we will order a zen from oneils in the states they are cheap as chips compaired to here £129(http://)
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hi guys just to let you know i got a pm from biscuit and hes finally got his boat on the water and hes very happy with the boats speed.maybe he will come back and give us a propper update of her performance?.
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Did he say what was wrong with the carb or engine set up then Martin?
After all the previous postings it appears that all has been tried but to no avail.
I am now very curious - unless of course a different engine was fitted...
Glenn
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Did he say what was wrong with the carb or engine set up then Martin?
After all the previous postings it appears that all has been tried but to no avail.
I am now very curious - unless of course a different engine was fitted...
Glenn
hi he bought a new piston and liner for it and it started,he had few probs with lsn but i think hes sorted it now he said the boat was fast and stable in strong winds so alls good.he says hes unwound two flex cables so im thinking he could have the wrong cables? right instead of left?.he says it came unwound near the collet i presume he means near the engine or he means ferrule and its the other end.im waiting for him to get back to me on this as its strange to unwind two cables in such a way.
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Cables must be wrong ones.
That's the only logical reason they'd unwind. The cylinder and / piston must have had some pretty severe damage to have been causing that many problems.
Any way, all's well that ends well.
Glad he got it going.
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well i told him via pm that i thought his cables were the wrong lay hopefully he will make sure next time before he loses his prop or worse!!.yea he said he had a 3ft rooster from it and everyone said his boat was the best there.he was running 25% nitro though which i thinks too much for that engine as they are only sports engines what do you think? i ran mine on 10%.basically the marine engine has the same specs as the plane engine .also i was going to ask you do you solder your ferrules on or use the loctite retainer 603 i think they use?.
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As to fuel, does not really matter, more nitro = lower temp., also need to alter tuned pipe length etc., not sure if an SC will be able to release the power and benefit from 25%, if it's power needed then a CMB is an easy option, normally seems to be plenty on ebay, I got a CMB 0.90 last year for 80 quid.
That seems to go OK too, although the boat is not finished.
I use 5% to 10% Nitro on my SC. Because I am tight!
My cable in the Miami had the ferrule and stub shaft soldered on when I got it. (From Prestwich). I just cut it to length required and clamped into the drive collet adaptor on the motor and it's been fine so far.
G
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seems nobody has any ferrules the right size in stock so im thinking of making my own from brass tubing and tapping the tube to accept 3 mm grub screws.the cable end will have loctite retainer added to stck the cable to the ferrule.i could loctite both ends i guess but then id have to remove the strut to get the cable out to regrease it .dave doesnt have the square cables so i got one from rc world.com wow they are cheap too!!.prop only cost me £14 compaired to about £25 from here.
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Are you just using the ferrule at the end of the tube to stop the shaft falling out of the boat?
G
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the ferrule is to join the two shafts together,flex to stub between the transome and strut .it will also stop the cable coming out of the boat also.
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Hi Martin,
In would have thought that for the amount of torque and general "grief" the shaft / flexi is going to get at that point then you are going to need at least silver soldering. I hve looked on Prestwich site and you are right, no square end shafts listed, but maybe you could change your engine drive collet, or gring a 1/4" round shaft to be square.
G
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Hi Martin,
In would have thought that for the amount of torque and general "grief" the shaft / flexi is going to get at that point then you are going to need at least silver soldering. I hve looked on Prestwich site and you are right, no square end shafts listed, but maybe you could change your engine drive collet, or gring a 1/4" round shaft to be square.
G
glen they use the loctite retainer over in europe on race boats with zens in so im sure it will be fine,from what ive been told its every bit as good as silver solder and easier to do ,also if it were to fail it does no damage to the cable unlike if a solder joint fails.the reatainer is not the same as thread loc its loctite 603 retaining compound i think is the number.as for the round collet idea no thanks im sticking with my clutch and have a square cable that fits.im going to drill and tap the brass to accept 3 or 4 mm grub screws to hold the stub shaft and loctite the other end.i know a guy whos used the loctite over here on his boat wih no problems !! and at just over 6 quid a bottle its cheaper than soldering too.
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Cool, let me know how you get on with it then. Sure it'll be fine.
When you going to stick some photo's up of your boat?
Got mine in bits again, decided to do a Winter refurb, new rails, new engine mounts and tidy up generally. To be honest got bored and pulled it to bits again. ;D
G
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as soon as i start building ill post a new build thread so you can follow it and hopefully give me some good feedback and a little help at least with the set up of the hardware and such like.this will be my first gas boat but im not new to building boats.i built this one from the same plans for a nitro plane engine.did you say your boats a miami hull?any pics of her and your set up would be nice.if you like you can pm me with them or just post here.
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Hi Guys im back!
Yeah got the boat going great, been waiting to get some pics to put on the site but they have not turned up yet, so will fill you in on the details, and add the running pics later.
AS you know I was getting very dishartend with the boat so took the gear out and decieded to sell it on E-Bay, but after a few weeks I kind of kept thinking about the work I put in to it and the money I spent on it, and read your posts again about those ready to runs so thought I would give it another chance. Got another piston and liner from Dave, re-biult the motor and waited for the next outing, well the day arrived very windy, we were at Stubbers outdoor centre 5 Acre lake would it run today? still a nightmare to start with plug lose, fuel every where but it started! so in it went, I could not believe how smooth the boat was in that rough water, but it only ran a few mins and stopped. When I got the boat back I leaned the bottom out a lot to try and stop the amount of fuel comming out of the carb and plug as I was trying to start it, this seemed to help, but the amount of oil and water on the belt and flywheel meant the belt would slip all the time, (very frustrating) just about to give up when a guy lent me some nitro cleaner. This cleaned the oil off the belt and I got it running again. It still revs it head off when you start it but once in the water its fine, leaned the motor out little by little all day top and bottom, done 3/4 of a gallon of 25% Duraglow, getting faster every run, rooster tail looked like 30ft not 3feet, (sorry Martin) handling was super smooth tunrs very tight without hooking even in that chop. Still more to come out of the boat as when I got it home I found that a load of paper towel had got dragged down the propshaft and It was very tight to turn so with the shaft free its got to run faster, plus the motor ran very cool and even though I kept leaning it out it showed no signs of cutting out on full throttle even though the main needle is only 3/4 of a turn out!! so very happy with it, not sure to get a better tuned pipe see how it goes next time, till then thanks for convincing me to carry on! hope to get some running photos on here soon.
Atb
Steve.
Ps Dave said solder the end of the drive cable.
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solder loctite its all good they use it in europe as dave well knows so ill give it a go i hate soldering.anyway if loctite can withstand the power of a zen im sure it can handle a weedy!!and pics are no good we want videos lol!!.
ps did i say 3 ft? meant 30 ft lol.and forgot to say get left lay cables no way should they unwind unless you got the wrong cable!!.
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Hi Martin,
The cables come from Dave so I would of thought they would of been ok.
Steve.
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;) Brings a tear to the eye, don't you just love a happy ending. Seems amazing that the liner and piston can have been giving so many problems. Still, really pleased that you got it going and are happy.
Glenn.
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Hi Martin,
The cables come from Dave so I would of thought they would of been ok.
Steve.
i hope you told him about it? it doesnt sound right to me ive not seen this happen many times and for it to happen twice in a short time seems very add to me.id double check the lay on it they have to be left lay cables not right.th very nature of them been left lay means they should be twisting tight when in use not the other way which would explain why they unwound.did you cut them yourself if so how?.let me know if you need a spare sc for it mines gathering dust.
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Hi All,
Can't remember if I posted this before on this thread, but a friend of mine had a well known engine from new (may have been Irvine) but one of the big names. He had problems for two seasons, before he discovered that the liner was 180 degrees out. The result before the liner was twisted to where it should have been, was a motor that was very hard to start, and would only rev. Absolutely no slow running, because of how far out the timing was.
Bob
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I did check the cable Martin, it is the right lay, cut the cable with a pair of wire cutters, it seems to unwind the outer cable and leave the centre, but this slips in the collet fixing and makes a mess of it. Did manage to cut the damaged end off and use it again, just moved the prop back ground a new flat on the shaft for the dog drive. AS to the piston and liner dint think this was the problem, I damaged this trying to run it in with the water pump, it was way too cool and semi seized. The motor still behaves exactly the same reving with the carb shut, but soon as it is loaded up in the water it runs fine, if I had done this in the first place it probably would of been ok, but it just didn't seem right to me but been brought up on Car, Helicopter, & plane engines which tick over and rev when you open the throttle, that SC kind of does its own thing out of the water but runs fine when its in!! Nearly bought a CMB 67 on E-Bay tonight, went for £160 brand new what a bargain?? but why do I always have a nagging doubt in the back of my mind when spending this kind of money on the old E-Bay? well thats it for now, hope to get some pics over the weekend, thanks for all the replies.
Steve.
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steve my engine ticks over just fine i dont understand why youres doesnt? have you tried to adjust the low needle?.it will allways rev higher than on a plane because theres no resistance when the props out of water.also i think the cutting the cable with wire cutters is your problem :o it needs to be done with a dremmel cutting wheel or a small grinder so you dont fray or loosen the outer cables.soldering the part your cutting will help too.where did you buy the cables?.i payed 8 quid for mine from hong kong!!.
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Yeah Martin, did wonder if I should of cut the cable some other way, as it does seem to fall to bits as your trying to cut it with pliers, not sure to solder the cable as the heat might soften the cable, what you think?
Cheers mate.
Steve
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i would solder it and cut it with a small hack saw it worked 4 me.
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Hi there again.
I wanged my 4"angle grinder through it just fine. I did wrap insulation tape around the cut.
So far so good, but I only have about 7 hours on it. Produced a nice clean cut, went easy ish so as not to create too much heat.
Glenn
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Solder and grinder for me....
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The Aeromarine flexi's I get from John Wright have the stub shaft (transom end) silver soldered on and then cylindrically ground to 3/16". Shafts from Dave or Mark Copley are just as good, but appear to be slightly less resistant to corrosion.
The other end has is plain and is cut to length for the collet. I cut them using a 1mm grinding wheel in a Dremel (or the Netto equivalent :) ) Do not try to cut too fast and keep stopping to let the fexi cool down, especailly on the last bit. The end should then look nice and square and does not need any additional work. Make sure the collet and tube are aligned accurately, keep the flexi lightly oiled and they should last at least a season.
Danny
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Hi
Just thought I would show you what happened to my brand new engine (SC60) after trying to run it in at home on a water pump.
This motor was brand new, thought I would run it in by circulating the water around the head with a fuel pump to save me time over the lake, the pump was run on 7.2 volts so there was a fair old gush comming out of the side of the boat and back into the water pick up bucket. As you have probably read was having a lot of problems starting it and keeping it going, then I noticed the compression had gone off, when the engine was stripped down I found that the piston had semi sized and destroyed the fit. I believe this was caused by the piston and liner not being able to reach there opperating temperature due the amount of water cooling the engine, this meant that the piston and liner could not expand at the same rate so I guess that the piston expanded more than the liner and seized resulting in the loss of compression. Lucky Piston and liner for the SC only £30. Boat is now running well, with only a trickle of water comming out of the outlet pipe but it runs cool for 10 Min's no problem, so lesson learned there then, looking to get a better carb for it as I think this has a lot to do with the bad idling and poor starting. Oh well nice afternoon, I'm out flying.
Atb
Steve.
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hi Biscuit
first may i say i am glad to here you did not give up with your boat. for me the one thing that has kept me interested in ic boating is that there always seems to be something you can do to improve your boat/engine.
i don't think you the only one to have problems with this engine mostly it seems the carbs can vibrate out of tune even vibrate apart,
if you are still looking for a good replacement carb try just engines out. they can supply you with a os carb (copy) these a very good i have them fitted to a couple of my engines & normally need no adjustment when set if there is 1 click is enough
keep on bating
steve
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Biscuit,
Would it not be better to run the engine in on the bench with an aero prop till you are happy with the way it starts and runs, and yes I would use an os carby as they are a lot better than the original type you have,,,,
Roy
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Biscuit,
Would it not be better to run the engine in on the bench with an aero prop till you are happy with the way it starts and runs, and yes I would use an os carby as they are a lot better than the original type you have,,,,
Roy
thats how i set up my engine too using an aero prop. but the flywheel will need to be removed and a prop spacer put in its place to do that!!.also what you think is the right seting for it with an aero prop wont be correct for a boat prop.they allways need more revs for a boat or it will stall when you throw it in.
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Hi
Just thought I would show you what happened to my brand new engine (SC60) after trying to run it in at home on a water pump.
This motor was brand new, thought I would run it in by circulating the water around the head with a fuel pump to save me time over the lake, the pump was run on 7.2 volts so there was a fair old gush comming out of the side of the boat and back into the water pick up bucket. As you have probably read was having a lot of problems starting it and keeping it going, then I noticed the compression had gone off, when the engine was stripped down I found that the piston had semi sized and destroyed the fit. I believe this was caused by the piston and liner not being able to reach there opperating temperature due the amount of water cooling the engine, this meant that the piston and liner could not expand at the same rate so I guess that the piston expanded more than the liner and seized resulting in the loss of compression. Lucky Piston and liner for the SC only £30. Boat is now running well, with only a trickle of water comming out of the outlet pipe but it runs cool for 10 Min's no problem, so lesson learned there then, looking to get a better carb for it as I think this has a lot to do with the bad idling and poor starting. Oh well nice afternoon, I'm out flying.
Atb
Steve.
Hi Steve / Biscuit,
As the others said, well done for sticking with it.
I think you surmised correctly as regards the overcooling (normally the brass sleeve will expand more than the aluminium piston, so that the fit loosens up somewhat while it is running - to achieve the correct fit when warm and run-in). I believe there is another important factor though - which is related to your running problems. If the engine revs hard when the throttle is closed, it is running in a very lean condition, and hence deprived of oil. If you add this to the fact that it was a new engine - therefore tight, and made worse by the overcooling, it's not surprising the piston and sleeve suffered.
The lean condition in itself will not do any good though, so the carburation does really need to be sorted. I broke a rod on a brand new SC .61 on shore - in the time it took to burn the fuel stored in the crankcase.
The SC carbs can tend to leak air around the main needle - which can usually be helped with a suitably sized length of silicone tube - all the way from the carb body to the outboard end of the needle screw. This will also grip the spring, and help to stop the main needle unscrewing. If it revs when the throttle is closed, with the low speed needle is screwed well out, it almost has to be an air leak or a blockage - unless you are using pipe pressure on the fuel tank. If you use pressure, sometimes you need to go very lean on the main needle to compensate for the pressurised fuel - leaving it short of fuel when you close the throttle. From what I have seen, the SC carb's don't like pipe pressure.
Agreeing with the others again, there are much better carbs out there than the SC, and some good options have already been suggested.
Good Luck and Happy Boating:
Ian
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Thanks Ian, Yeah must be an air leak some where, but it runs fine in the water, still waiting for the next outing, wish I had a lake I could go to anytime!! not run my boat for a month now, have heard that they are prone to braking rods. Got dvd of my boat running will try and post a few pixs!!
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Thanks Ian, Yeah must be an air leak some where, but it runs fine in the water, still waiting for the next outing, wish I had a lake I could go to anytime!! not run my boat for a month now, have heard that they are prone to braking rods. Got dvd of my boat running will try and post a few pixs!!
post the vid on utube or similar then we can all watch it hehe!!these engines are strong ,better than os in my opinion.
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Hi All,
Sad really but boat up for sale, got no where to run it so £350
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Hi All,
Sad really but boat up for sale, got no where to run it so £350
what happened? .
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Well we lost our lake over to fishing, and Stubbers was just a one off, my model shop seems to have lost interest, its selling boats but don't seem to keen to hire out any lakes. Could join Brentwood, but thats a fair trek and don't want to join anymore clubs. We did have a guy who ran electric said we could use his lake on race days but we would have to join Electra and only have an 1/2 hour slot. Shame, but least I had one good day out with it, no one seems to have much enthusiasm any more down here, so need some cash to buy some more lipos for my Helicopter.
ATB
Steve.
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sorry to hear that mate so why wont they let you run boats on a fishing lake? do they think your gonna hurt the fish lol?.are there no council run lakes near you at all ?also id check that the club you mentioned actually owns the lake they use cos if they dont they cant stop you using it whenever you want to.
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Say it's a Bait Boat, for fast fish.
sorry about that I know its getting harder to sail these days
Peter
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Yeah your right no where now days seems to like I/C even our flying field has had its I/C days cut right down. So remember nice boat up for grabs ! lot o time and money spent, I know its only a SC 61 but goes like a bat out of hell.
Steve.
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Well, I would buy it, but I heard the previous owner had trouble with the engine...........
:D
Glenn
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The word is had !! now its got a new piston and liner its fine :P
Cheers,
Steve.
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Ok , Take it no one interrested, ???
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what heppened to the pics of her running?
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They were on my model shops computer, they could not get them on to disc or something like that. :-\
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Can anyone tell me what this spring type clip thing is doing in the barrel of my SC 61 Carb? have not sold the boat (although I wish I had) so took it out today to a new piece of water, but as I was starting the boat, (nightmare) the barrel decide to lock open flat out, this spring thing had slipped down and stopped the barrel from closing. Will take it out and run without it, but why is it there??
any help/
Thanks
Biscuit
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hi biscuit
i no expert on sc carbs but it looks as if its a choke, i expect the same carb is used on the sc 90 but without the sleeve, if it is removed you will have to re-set the carb as it will suck in more air than fuel, running without it will probably make it not throttle as well
steve
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Yeah did wonder that, but it is so thin, cant really see this making much difference, my cars have restrictors in the carbs these can be as much as a 2mm wall thickness, this is .5 of a mm, still I am open to all suggestions.
Thanks
Biscuit.