I like the baby pm but I don't know if there anything allot better. Is there anything better and if it is how much more? Also what would be the best 70cc kit for the exhaust and what else could I change to improve performance?
Take a read through this mate: http://www.scootershack.co.uk/scooter-tuning/exhaust-barrel-matching-guide-t2948.html
The best thing to consider is your budget, not just for now but for the next 12 months or however long you intend to keep the bike. if you use it every day i would highly reccomend having a spare engine on stand-by ready to bolt in. if you don't want to go down that route then i would suggest just going for an iron 70 kit, something like the malossi sport or the top performances/DR kit, they offer a reasonable increase in power without losing too much reliability. as far as an exhaust goes for these, you may get away with using a yasuni City 16, i would reccomend a lower level pipe though, something like a yasuni R or a TP nardo replica, they seem to be getting reasonable reports from the continent. like i've said though, it all depends on your disposable income.
u can use the pm on a 50 or a 70 i personally like them but a lot of people say they snap ive never had this problem tho