mmnn,they were originaly,at 16odd bhp,but the 650 is in quite a high state of tune(relativly),and can over rev the crank,also timing chains can snap....................ask bis 13,remember,nearly every 126 has had a crap service record...........even at low milage they have suffered from clogged filters/ cheapest oil etc etc....stick a rev counter in,keep to 5000 max with good oil etc.......my standard 650 will rev out to 5000+ in second..so your downhill runs are prob up to a sustained 5500/6000rpm.....not good.... :wink:
the car i have now was blown up on the motrway coming to jersey,the guy just held it flat out,it went with a big bang he told me,snapped crank said the recovery/mech guy.......... :roll: