What Bore?

[Jake400ex]

I've been thinking about boring my '06 400ex to a 416 to a 440 what do you think would be best? but i also want to run on super unleaded fuel from the pump. i have a full yoshi comp pipe, and a k&n airfilter.

[CHEVYZ]

From your sig you have no other mods. What all do you plan on doing to the bike in the process? Unless you have "big" plans for it, I would stick to the smaller bore 416.

[blasterandy]

Yea get a pipe and filter. And sum suspension. Suspension will make you go faster than any engine mod can do. I would personally go with the 416 due to the high rev. But a 426 kit sounds good i don't know who makes it. A 10.5.1 compression is good for unleaded 93oct, i hear people running 11.1. I would personally run a mix with 11.1.
just my .02 ;)

[Jake400ex]

I already have a pipe and a filter i just havnt put it in my sig yet. i just want to have a little bit more torque lower end, and a lot more up top. and a higher top speed

[exrider272]

i have a 426 in mine and a white brothers pipe and runs good also im thinking of getting a 460ex kit for are drag bike by trinity racing

[CHEVYZ]

Originally posted by Jake400ex
I already have a pipe and a filter i just havnt put it in my sig yet. i just want to have a little bit more torque lower end, and a lot more up top. and a higher top speed IMO a bore really doesn't do much. I would suggest getting all of your basics first, unless you are going to go full on and do everything. First thing I would do is get a good cam to suit your style, and get a high compression piston.

[oldskoolex400]

get suspension first and make it wider and lower