how much of a differance will boring my sport .40 over make will i be able to beat a 400 ex ? banshee!???????

 

Anytime you increase displacement you will gain power. If you do nothing else but bore it .040 you might get 1/2HP, but nothing else. The big bores give you a bunch of torque, but for all out racing the smaller bores do better because it's easier to fill the top end through the transfer ports. Dont waste bores if you dont have to. There are other ways to increase power.

 

i also have an hpd pipe with a uni filter no air box and a wiseco piston

 

I wouldnt bore any motor until it needed it.But if you do tear it down send the jug to Bubba 297 and have him port it for you and go to some better reeds.

 

on a very modofied 400,you'll loose top end big deal,but you'll gain low end torque and throttle response,the powerband will be flat on mid to top end.it is good for slow/rough trail riding when torque is the obsolute needs or hillclimbing,the motor will "rattle" a lot more then...

 

yup send that engine out to bubba he will get some good hp numbers out of it.[img]i/expressions/face-icon-small-smile.gif[/img]