Ok. So my 04 400ex is getting a lot of upgrades all at once and I’m looking for suggestions on where to start the jetting. I would rather start rich and have to lean in out then start lean and blow it up with all the money I’m dumping in it.

The old setup was all stock with a gutted stock pipe and holes in the air box lid. And I think we had the main jet at 165. Not sure but think it was that. And I believe a 42 pilot.

Here’s everything it will be at when done.

Grinded out the welds in factory header. Hmf slip on exhaust. Stock filter with no lid and using an outerwears pre filter. Ported and polished head flowing best possible (ported by a professional). Bored .040 over (1mm) to a 406 using a wiseco high compression piston (11:1). And also installing GT Thunder heavy duty head studs.