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[Patternmaker]

Ryobi  30cc leaf blower conversion to water cooled. marine. Bought from ebay for £24.00

Well made engine with solid con rod, 2 piston rings & fairly light, good project for conversion.

I ditched the clutch and pull start, machined the fins from the face of the flywheel, manufactured a pulley which also locks the flywheel..
Flexi shaft coupling.tapped to 9mm to fit crankshaft.

Machined the fins from cylinder and made a water jacket from 3” Dia Aluminium bar much larger than Zenoah with increased cooling capacity.
.

[martno1fan]

Loveley work Mick look forward to seeing it finished.
Mart

[Patternmaker]

Cheers Mart, just engine mounts & cooled manifold to make.

[martno1fan]

Some people can be a bit negative about the use of these cheap strimmer type motors but ive found them to be quite reliable when ive used them.Ok not the fastest motors out there but with a few tweaks which im sure you have in mind theyre great value.I only wish i had the access to a lath and the skill to use it  .
Mart

[Patternmaker]

Some people can be a bit negative about the use of these cheap strimmer type motors but ive found them to be quite reliable when ive used them.Ok not the fastest motors out there but with a few tweaks which im sure you have in mind theyre great value.I only wish i had the access to a lath and the skill to use it  .
Mart

Yes Mart your absolutely right about the negativity, as I have said before If I can produce a reasonable reliable engine conversion for under £50.00 including engine, materials, engine mounts, coupling & header its well worth it.
The Ryobi was originally an American design now manufactured under licence in China, spares are easily available.

The 30cc engine has a 36mm bore and 30mm stroke, with a but if tweaking, change the carb I hope to get around 1200rpm.

Dave reckons it will turn a 482 prop, 82mm Dia 114.80 pitch.

Mick

[Patternmaker]

New exhaust flange made from 3” dia aluminium bar, comparison to Zenoan smaller flange.

[martno1fan]

Hi Mick yea the x482 or prather 280 were the best props for my old weedy powered boat ,that was just with a carb change to a wa167 carb.
 That said after a bit of porting (nothing exotic as i know nothing about it really i just copied what others had done etc) i could spin a smaller prop .I found the 3 blade 6717/3 ran ok also but i think maybe a 70 mm diam 3 blade prop would have been even better.If you can get 12,000 rpm a 275 prop might be another decent prop to try,its what a lot of the Americans used on the old homie powered boats.
 The flange looks very good you do nice work as allways  .
Mart
 

[Patternmaker]

Finished engine, total weight 1.5kg, getting 10750rpm with existing carb

[martno1fan]

Looks very nice Mick should make a good sports engine  .
Mart

[Patternmaker]

Cheers Mart, just the hull to do to put it in.

Mick

[Patternmaker]

Final modifications, carburettor insulator made from 3” dia aluminium bar with Teflon gaskets to prevent warping when hot, a common problem
With Zenoah's, causing bad idling and loss of top end power.

Smaller plug cap to fit under hatch cowl.
Getting 11800 rpm with 16mm venturi carburettor without tune pipe.
 

.

[phillnjack]

Youve turned that into a real nice piece of kit.

I do like your cylinder jacket for the cooling,very good work.

those car and exhaust plates also look very good,you should make a few to sell,im sure
people would buy them as they look very well made.

you now have a very nice engine, and saved a few hundred quid as well.

very well done, what boat is it going in ?



phill

[Patternmaker]

The engine went in this boat!

Mick

http://www.modelboatmayhem.co.uk/forum/index.php?topic=24616.0

[dadandlad]

What angle and width do you cut the starter pulley vee
Cheers Mark

[Patternmaker]

Hi Mark, exactly the same as a 12v starter pulley.

Mick

[dadandlad]

Thanks Mick
Just one more question,have you kept the same diameter or made it bigger so as to lower the gear ratio to make it a little easier on your starter motor
Thanks Mark

[Patternmaker]

Hi Mark, the pulley dia is 2.25"
If you are converting the same engine you will need a Sullivan starter, it has a lot of compression.

Mick

[phillnjack]

I agree with the above
as cheap starters are not worth buying, they dont have the ooomph for some engines.

ive come across afew that will no way start a sc91 ,unless on 24 volts.


i do think this engine conversion is very good.




phill

[dadandlad]

Cheers Mick
I will bear that in mind when i purchase my starter
Total agreement with phillnjack the conversion looks very proffesional