400 Carb Jetting

[Bolinracing]

300ex MX bike with sparks pipe, K&N, no lid, aftermarket CDI and 400ex carb. I need a ball park starting point for jetting the 400 carb. I will be putting all the above mentioned parts on this weekend. Thanks for your help.

[Bolinracing]

anyone?

[SteveRidesQuads]

what motor mods do you have?

im running 42/148 with
cam, ported and polished, bored, piston, oversized valves, no lid, and sparks.

[Bolinracing]

No motor mods yet. Just K&N no lid, sparks exhaust, 400 carb, and CDI. Does anyone else run a 400 carb that can give me some help. I would love to see an average here. If not I will start with the 42 148 and move on from there. Thanks.

[bwamos]

If you have a fairly stock motor w/ pipe & filter I've been told that the best starting point is right at the 400ex stock jetting.

I think it's a 138k w/ a 38 pilot.