Why not use the spiderbox from a Yerf-dog go cart connected to a scoot front end ?
I'm trying to get one together now, I'm mixing 06 hysung front fork to the spiderbox (BMI 150cc). I just decided I'm doing it wrong and going to dump the rear shocks and make it a hard tail. cutting the spiderbox and moving it forward in frame as motor mount, directly under seat. chain drive from xmission jack shaft to rear axle...
<------ View my photos on left
Note: build Monst_1 & 2 are photos of a bad build idea