P200E Engine/crank probs?

Hi, I have fitted a standard p200e engine to my Rally 200 but Im having problems with the engine. I think the crank may be a racing crank, mazzuchelli, but would this have any effect on the carb or timing
One minute the scoot starts & rides ok then it won’t start unless I take off the air filter. I have replaced the carb & carb box & air filter with new ones but still have the same problem. After riding it for a while,then switching it off, I have noticed fuel coming up through the air filter, would a racing crank have this effect on a standard engine?Any help much appreciated,Thanks Chris[:shock1:]

thanks for reply, yea, when you take the air filter off a lot of fuel is coming out of the carb & it seems to run better a higher revs. If I fit a big bore kit would this get over the problem as I don’t fancy taking the engine out as scooter as just been restored?

ok, so if I buy the polini kit with the gs piston this will be ok with the crank I have at the moment? do I need to change the cylinder head like you have to on the malossi?

Hi, I have taken the engine apart in the frame & yes, its a racing crank, got 3 holes cut into it, so I have removed it & will put a standard p200e crank back in, will let you know how I get on but thanks for all your advice!Chris

A race crank gives you more inlet timing. This means that fuel is being drawn into the crankcase for a longer period than standard. If the rest of you engine is standard it will be unable to burn the extra fuel and will spit back the excess. The difficulty starting is also a symptom of this. Most racing cranks have too much inlet timing especially the mazzuchellis and this causes a very lumpy acceleration untill the motor is spinning fast enough to burn the extra fuel. If you intend to keep the engine standard you will have this problem untill you remove the crank and refit a standard one.

Sure im using the Polini with the GT piston in at the minute.These used to work pretty well as a bolt on kit. Likewise with the pinasco.

No and yes

While your thier, check the sealing pad on the cases!
If its a modifeid crank it will have been polished?
three holes???its not lambretta is it!!!

or full circle!