Recommended Jetting w K&N power up kit?

[Dizing400ex]

Hey guys,

what do you recommend as far as jetting with a 06 400ex, spark arrestor removed, timing advance key, CDI, KN power up kit, dyno jets at about 2000 ft above sea????

If not, whats a good place to start?

thanks,
Dustin

[asmith]

well, stock is a 138 main, so with your moderate air flow increase via filter and reduced back pressure via arrestor removal, i would start with a 150 main and plug check it to see where your at for fuel mixture from there.

[NCexRider]

Having your spark arrestor removed makes no difference performance wise, just gives off that "empty can" sound. Also, Dynojets are sizet differently than stock jets. Install the 160 main jet, put in the Dynojet needle on the 3rd groove and think about removing your airbox lid. You can feel out where your air/fuel mixture screw should be set & you'll be in business!