I am using Vespa Cosa 2 150cc. My bike is quite old, piston and cylinder are not good.
Last month I have change piston to Kawasaki 59mm, I make cylinder bigger :). But I am not really happy with it.
Now I am thinking of 2 option as below, please give me your advices,
1. I will change only Piston and cylinder, I am looking to buy Racing cylinder Malossi MK II
If you have use this set before, pl. give me opinion how good is it, is it can be jam easily? Did this set increase speed of my bike?
2. Or I will buy a Tuning kit Polini Sport 177cc
This kit is look more good for me but I read from somewhere that for Polini it can be easy jam between Piston and cylinder, it is correct.
also, for this kit, pl. advice do I need to modify the engine (crank case)?
I can do a cabulator, piston, clutch replace, but never open crank case before.
I am in Vietnam, so every import time is make me crazy, so I am not much consider price between those 2 sets.
Waiting for you advice,