Good morning, Recently I've completely overhauled a Piaggio 125cc Hecagon engine. All the bearings are replaced, I've replacee the 125cc gears for hexagon 150cc gears. New malossi clutch New malossi variator New original oil pump New 172cc gilardoni cilinder New bgm crankshaft and bearings New bearings in end gears New bearings in the rear pulleys New DDL tuning exhaust New rear wheel bearing Last week I was on the dyno and it runs really good with no problems. The engine performs like there is nothing wrong with it. It produces 22,5HP at 9100 rpm. The only problem with full throttle you can hear a rattling/cracking sound from the rear of the engine cases. The tuner never hears this sound before and before the day was over we did not figured out what makes this noise. When i got home I openden the gears but i didn't see anything wrong. Oil was nice and clean witt no debries in it. I replaced the bearings in the rear pulley but you still hear the sound. I'm worried to break something if i keep on driving with the sound. Only with full throttle you hear the noise, with half throttle everything is fine. Anyone got an idea what the problem might be? Sorry for my English, I come from The Netherlands.
There are two needle bearings in the clutch pulley halves, front and rear. I have known the front one to fail before
I would of thought you'd get the noise at any speed ? Is it "pinking" does it need a bigger main jet ?