new and old compareson

[billy270]

ok here goes i was riding about a 150 mile trip the outher day just to get out.......and my brand new motor that has been well broke in...... locked up ......well i tore in to it to day and the colpret was the lower conecting rod bearing had sezed up i bleve the race had failed are some thing along those lines well the only damage was to the conecting rod and the bering well me being dum *** me..... i bought an older 80cc motor that has been siting for at least 5 years i took it apart not knowing the history and i notist the lower baring on the where just nedle barings.... well i test fited it to the crank fit perfect..... the top had the old style bushing well i maschined it out and fit the rist pin and uper baring well it would not start i noticed it did not seem to rise althe way to the top of the cylender......well i put the pestion next to each outher one taller than the outher..... older was taller......from the rist pen to the top....... any one know if the rods are the same are not lingth wise..... sorry the speel check dont work form my comp i am the worst i know

 

[GearNut]

Different manufacturers use different length connection rods and different height pistons to obtain proper compression ratios. These engines are made in 3 different factories and the internals are different between all 3, and sometimes even different parts are used in mid year production.

The best way to almost guarantee matching parts is to know the vendor that sold the engine originally, and what factory made the engine.

Grubee/ Skyhawk.
Flying Horse.
Raw.
Jet.
Those are the manufacturers, I think Jet is in cahoots with Raw, but I am not positive.

I think that Kings deals with all of them.
http://www.kingsmotorbikes.com/2_stroke_bicycle_engine_kits.htm?scart_affiliate_id=23