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Author Topic: SC 61 break in.  (Read 14403 times)

glennb2006

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Re: SC 61 break in.
« Reply #50 on: February 05, 2007, 06:21:18 PM »

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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martno1fan

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Re: SC 61 break in.
« Reply #51 on: February 05, 2007, 07:26:14 PM »

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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glennb2006

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Re: SC 61 break in.
« Reply #52 on: February 05, 2007, 09:24:27 PM »

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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martno1fan

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Re: SC 61 break in.
« Reply #53 on: February 06, 2007, 12:02:23 AM »

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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glennb2006

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Re: SC 61 break in.
« Reply #54 on: February 06, 2007, 11:05:52 AM »

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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martno1fan

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Re: SC 61 break in.
« Reply #55 on: February 06, 2007, 12:06:52 PM »

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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glennb2006

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Re: SC 61 break in.
« Reply #56 on: February 06, 2007, 12:40:28 PM »

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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martno1fan

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Re: SC 61 break in.
« Reply #57 on: February 06, 2007, 01:06:56 PM »

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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Biscuit

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Re: SC 61 break in.
« Reply #58 on: February 07, 2007, 07:20:14 PM »

 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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martno1fan

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Re: SC 61 break in.
« Reply #59 on: February 07, 2007, 10:17:25 PM »

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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Biscuit

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Re: SC 61 break in.
« Reply #60 on: February 07, 2007, 10:59:03 PM »

Hi Martin,
The cables come from Dave so I would of thought they would of been ok.
Steve.
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glennb2006

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Re: SC 61 break in.
« Reply #61 on: February 08, 2007, 01:28:36 AM »

 ;) 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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martno1fan

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Re: SC 61 break in.
« Reply #62 on: February 08, 2007, 08:21:19 AM »

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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BobF

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Re: SC 61 break in.
« Reply #63 on: February 08, 2007, 12:08:40 PM »

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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Biscuit

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Re: SC 61 break in.
« Reply #64 on: February 08, 2007, 10:27:27 PM »

 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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martno1fan

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Re: SC 61 break in.
« Reply #65 on: February 08, 2007, 10:51:20 PM »

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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Biscuit

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Re: SC 61 break in.
« Reply #66 on: February 09, 2007, 09:48:43 PM »

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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edible_engine

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Re: SC 61 break in.
« Reply #67 on: February 09, 2007, 10:07:46 PM »

i would solder it and cut it with a small hack saw it worked 4 me.
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glennb2006

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Re: SC 61 break in.
« Reply #68 on: February 09, 2007, 11:51:55 PM »

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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w3bby

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Re: SC 61 break in.
« Reply #69 on: February 10, 2007, 09:19:05 AM »

Solder and grinder for me....

omra85

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Re: SC 61 break in.
« Reply #70 on: February 10, 2007, 07:40:19 PM »

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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Biscuit

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Re: SC 61 break in.
« Reply #71 on: February 11, 2007, 01:25:19 PM »

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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retro boats

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Re: SC 61 break in.
« Reply #72 on: February 11, 2007, 02:41:15 PM »

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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cbr900

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Re: SC 61 break in.
« Reply #73 on: February 12, 2007, 02:29:03 AM »

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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martno1fan

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Re: SC 61 break in.
« Reply #74 on: February 16, 2007, 05:47:21 PM »

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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