yea i know what a 5 hp briggs is, my son races one thats on his mini bike at the local mini bike races, they both run on alcohol but the mini bike dont smoke, he does. but i couldnt say for sure that it was 5 hp when new because it may have dynoed 4.9 hp or 5.1 so that cant be verified. obviously now with cam,head,porting&whatever else is done my guess is as goog as yours,without dynoing it who knows? the question was how fast can everyones mini bike go??not what mods or how it was verified that was the mini bike rule makers input.did you dyno yours yet? 25mph aint very fast but when you are on your hands & knees it is. :doah: is.