I run a 15/40
78 Pinto
High compression head (50cc one not 70cc)
Polini reed valve
15mm bing
78 jet (need some adjustment on that)
Techno Estrol pipe (I dont use pedals on the Pinto. I have 11 other bikes with Pedals, I think I can remove them on one of them without getting shit from retarded moped purists) Keep watching this guy till he puts a Puch one up:
http://stores.ebay.com/treats-hq-discount-puch-moped-parts
Take off is great. Vast improvement on takeoff when I went from biturbo to Techno Estrol.
with 16/40 I was clocked at 48mph
Id say I lost about 3mph with the 15 tooth but it also gave me better takeoff.
I can run from the Baltimore Nebri with more uumphh now.