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Old 12-04-2008, 04:32 PM
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Dan Dan is offline
Join Date: May 2008
Location: Moosylvania
Posts: 11,850
Default Re: GXH50 and a pocket bike clutch?

Thank you, this is the fun part. The plotting, scheming and planing. Second only to the tweaking and tinkering which of course is second only to ridding.

I did not know an adapter would be needed. Just for mounting? The GX50 max's @ 7200 and the clone at 6800 or about? Now you have me wondering but some one will let us both know.

In looking at building a reduction gear from scratch, Oscculy (SP, sorry bud) turned me on to they had some great thoughts. I have their permission to post an email they sent me;

Dan-- you have quite a challenge with that engine. The crankshaft
length is only 1.250" long which is too short to support a clutch, the
engine idle speed is around 2,700 to 2,800 and top rpm is 7,200rpm which
means you are going to be going like a bat out of ****. Several people
have done it and they used the Whizzer pulley belt which is almost the
rim size of a 26" bike. We made a crankshaft extension for them but it
isn't the easiest way but what the heck all you have is time to get it
to work.

I have another suggestion. Do a jackshaft arrangement so you are
slowing the crankshaft turn speed down so you have a controllable speed.
See attached pictures. We are going to shorten the tube by 4.5". The
gear on the engine is 12 teeth and the lower sprocket is 24 teeth. What
does this do? When the engine is turning 3,000 rpm then the jackshaft
is only turning 1,500 which prevents you from bogging down the engine
when you initially get going and then at full rpm of 7,200 you are only
going 3,600 which is standard for most 4 cycle engines and the clutches.
This way ANY clutch you want to buy will work on the jackshaft.

James F. Donovan
Max-Torque, LTD.
2180 Corporate Lane
Naperville, IL 60563
Phone: (630) 369-9600
Fax: (630) 369-9686
Website: MaxTorque

He has great pics that he sent along that I can't find!!
worst apocalypse ever

Last edited by Dan; 12-04-2008 at 04:34 PM.
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