GY6 1P57QMJ vs. 157QMJ

[marvin1966]

Hi guys,

I got a new china-brand 150ccm scooter (Hisun 150T-3). Recently I checked a shop offering tuning cylinder kits between 160ccm and 200ccm. Some of the descriptions show a warning: "this kit is for the 157QMJ and NOT for the 1P57QMJ engine!"

According to the label on my engine, I have a 1P57QMJ model!

Could anyone here explain the difference between these two engine types if any?

thanks

Marvin

[mx5tc]

The 157QMJ is the most common Honda based GY6 clone (has 4 bolt valve cover). I think the 1P52QMI and the 1P57QMJ are copies of a G3 made in Taiwan. AFAIK, cylinders/pistons/heads don't interchange between the two variants. Autotech355 on Ebay sells big bore kits for both motors; his notes on the 1P52QMI/1P57QMJ big bore kit say that it will not a fit a standard GY6 clone because the cylinder head is taller.

Mitch

[kink]

I don't know how much faith I would place in that. My engine has the 1P57QMJ designation and it is a 4 bolt valve cover.

There are definitely variants of the GY6 platform. As for whether you can tell them apart by the engine stamp or the number of bolts on the valve cover, I wouldn't be so sure.

[marvin1966]

Ok,

thanks for the fast replys. My engine has a 4 bolt valve cover too although it is a 1P57QMJ. I´ve seen the description at the autotech shop but did not really understand it. Does anyone here knows the measurements of the head of a157QMJ engine type? Then I could compare them.

best

Marvin

[mx5tc]

Sept 8, 2008 11:08:35 GMT -5 kink said:

I don't know how much faith I would place in that. My engine has the 1P57QMJ designation and it is a 4 bolt valve cover.

There are definitely variants of the GY6 platform. As for whether you can tell them apart by the engine stamp or the number of bolts on the valve cover, I wouldn't be so sure.

I didn't mean to imply that the a 1P57QMJ didn't have a 4 bolt valve cover; both it and the 157QMJ have 4 bolt valve covers. The Yamaha based GY6 clones are supposed to have 2 bolt valve covers; not sure of the engine stamp for those models. The engine stamp should enable one to tell the more subtle model differences (1P57QMJ vs. 157QMJ) that are not apparent from a cursory external examination.