Isomoto 125

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Racer97
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Isomoto 125

Post by Racer97 »

Has anyone worked on a Isomoto 125? I need to remove the flywheel to access the points. I don't know what size puller to order. It measures about 25mm and 1.5 pitch but I haven't been able to locate that size.
miniv8
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Re: Isomoto 125

Post by miniv8 »

No idea what engine this is, is it from a pit bike? Most are Honda replicas. The kickstart engines have a different thread for the flywheel than the electric start ones.

There are cases with a set of ten pullers on amazon for less than 40 bucks.
Magnús Aðalvíkingur Finnbjörnsson
Racer97
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Re: Isomoto 125

Post by Racer97 »

It's a 1955 Isomoto 125cc 2 cycle dual piston one crankshaft street bike from Italy. The manual is in Italian so I can't understand it. One piston is basically a supercharger from what I've read.
miniv8
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Re: Isomoto 125

Post by miniv8 »

Wow that's really cool.

Do a search for ABN Flywheel Puller on amazon.

These include M14xP1.5, M16xP1.5, M18xP1.5, M19xP1.0, M28xP1.5; 5 double-ended pullers – M20xP1.0 & M27xP1.25, M22xP1.0 & M25xP1.5, M22xP1.5 & M26xP1.5, M24xP1.0 & M27xP1.0L, M26xP1.0 & M28xP1.0; All righthand external threads excluding M27x1.0
Magnús Aðalvíkingur Finnbjörnsson
Racer97
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Re: Isomoto 125

Post by Racer97 »

I got one thanks. 27mm
Dan Timberlake
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Re: Isomoto 125

Post by Dan Timberlake »

Does the combustion chamber look like a Puch/Sears "twingle" ?
https://i.ebayimg.com/images/g/OrgAAOSw ... -l1600.jpg

After poking around on the Net it appears twingles came in several configurations, even from the same company ( Puch).
Pistons side by side with a murderous forked rod.
https://www.pinterest.com/pin/675258537869752465/,

Others fore and aft. With a master and slave rod setup.
https://image.jimcdn.com/app/cms/image/ ... /image.jpg

fore and aft is the setup I recall.
Sometimes the front piston has the intake and exhaust ports.
https://i.pinimg.com/564x/a0/ab/d6/a0ab ... 7860c6.jpg

Other times the front piston is the exhaust, and the rear handles the intake and transfer upstairs.
https://berniesbikeshed.files.wordpress ... 0&h=480ems


I think to qualify as supercharged, an enormous 3rd piston is needed, like this DKW race bike.
https://www.pinterest.com/pin/421579215129754716/
Racer97
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Re: Isomoto 125

Post by Racer97 »

Yes it does.
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Re: Isomoto 125

Post by Racer97 »

Isomoto is front to back pistons from what I've found. I didn't take the engine apart. The bike was sold at Mecum in 2017. It was restored in Italy before that. Someone didn't take care of it and must have left it outside or something. Now I bought it at a yard sale for cheap. It's hard to find part in the US.
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