i have an 86 sp125 and i was wondering if anyone here knew what the largest engine that i could swap into my bike is without major modification. the 125 is fun, but i love commuting on this thing and the 125 just isn't hauling my 225lbs around well enough. i was told by the previous owner that there was a 250 that fit, but i wasn't paying too much attention at the time to be honest. i'm pretty sure i'd be happy with a 250 in it, but wouldn't mind bumping to a 400ish if there's something out there.
thanks in advance for all the help!
sarge