Does anyone know how to identify....without taking the engine apart.....whether a 400ex has a big bore kit. I bought a used 400ex from a guy....who got it from someone else....who told him it had a 440 kit....I did a couple drag races with a known 416 and my quad pulled away.....I was hoping I could tell with a compression difference...I cant seem to figure out any way to be sure what the motor is....any suggestions would be great

 

There is no exturnal way to tell if a motor has a bigger bore than stock.. As far as the compression, that can be misleading too, a stock bore machine can have any compression a big bore can. And a big bore may have a low compression piston.

 

The only way is to mesaure the bore or piston.

 

You should be able to tell by the seat of your pants. The sock 400 is nothing compared to a 440!

 

There is something funny going on cause I am 260 lbs and i walked away from a 416 with a 165lbs guy on it....it looks like this quad had some money dumped in it....LRD exhaust, revbox, axle,beadlocks,radials, protaper's, but dammit he didnt do a damn thing to the suspension. Why do all these rabbits want to go so fast when its more fun to hop??????

 

this sounds dumb but would it sound any different if they had the same pipe?