Modern Vespa

Hi,
I have a Piaggio Fly 50 with the Malossi 80cc kit and the Power cam.
It's over 15km is running and no problem, top speed 45~50 mph.
Always run Premiun fuel! My spark plug color is light brown and i use a #78 main jet.

When the motor is hot, i hear a stange noise when i accelerate (after a stop or Redlight). It makes a sound come from the motor " like popcorn popping " not too loud but noticeable in accelecration. When my speed is stable it's finish!?

I don't know if it's a normal sound with a 4 stroke motor when he work hard???

Thank's for your help!

Alain

idk, maybe it is ovrheating a little becouse of all the mods. do you have a aftermarket pipe on it? and aftermarket pipe would elemanate alot of the back pressure and make your motor run cooler. that is my best guess becouse it only makes that noise when the motor is real hot, and then when your WOT. i strongly beleve you need a pipe on it.

If it's a 4-stroke, I'd try a tank of higher octane gas.

what octane is in it now? if it is 89 maybe try 93 and if your running 93 i would get a pipe.

I don't know if they have a after market exhaust for the Piaggio Fly 50 (80cc)???

since your already running high octane(or as high as it gets these days)you need to look elsewhere, is the main jet the right size, running too lean maybe? the pipe might help if your still running the stock one.