Re: hi from malibu
I think I would go with the Grubee.
These engines are all extremely similar, and most parts are interchangeable.
It all boils down to getting one from a respectable seller.
The better sellers stand by their warranty.
I'd get the slant head 66cc Grubee from GasBikes but that's just my opinion.
Whatever you decide it will take patience and time to get it right.
Do your research about everything about the bike kit.
There are a lot of talented, imaginative minds here with buttloads of insight and experience.
Welcome to the most fun and addicting hobby out there.