250x with 400ex carb?

[nemesis]

My brother just got a 400ex carb for his 250x and we need to jet it. What jet sizes should we start at?
The motor was rebuilt but not sure how far they bored it. It has stock exhaust still and stock filter.

[2muchquad]

stock exhaust?i wouldnt go to a bigger carb until you had some motor work done.your motor in its current state doesnt need any more fuel.engine components actually work as a "system".no need for a bigger carb when your still running the restrictive stock exhaust.you'll turn your 250x into a dog with a bigger carb right now..:(

[nemesis]

This is my brothers quad and I am very familiar with a/f ratio and back pressure.

He bought the carb because his was bad(don't know what is bad I'm just trying to help him). He has an aftermarket exhaust for a 400ex that he is going get modified to fit but just wants to get the quad to start before he does all this extra work.

It does have motor work, I believe it is roughly at a 270cc and he asked to have the highest compression piston that can be used with pump gas, so I assume it is a 12.5:1 compression piston.

Can someone with this carb on there quad give me there jet sizes? I can go up and down from there I just want a starting point.