Re: Splitting the crankcase
there is also a differance in stroke !!!
the dax f80 has a crank thats ground for 40mm stroke and all others are 38mm
so if the biggest motor is what your after then make it a dax kit
but you can get the other 66cc motors anywhere
if you want ease of parts availability then get a dax or pk 80 you will have a true 70cc motor that has standard parts
i like the grube gt5 personaly though to build apon i just seem to be able to extract more power from the stock factory port map than any other motor even though its only 66cc vs 70cc. the gt5 has differant and parts are hard to come by so be warned
IE: the jug has differant porting and the rod is longer and the piston has a differant wrist pin location