LRD Jetting?

[cotttonwoody]

I was wondering how i sould jet my 400ex with a full lrd exhaust, air box lid on, stock filter, about 4000+ elevation. Temp is around 65. Right now i have a 152 main in, which i am sure is probley to small.

[cals400ex]

a 152 should be close. i wouldn't go above a keihin 155 at that elevation.

[cotttonwoody]

Really? LRD suggest a 165 main with the lid off and at sea level.

[LaSalleKid]

Well then,

do what they say. They know what they are talking about.

[cotttonwoody]

BUt what they said is for the lid off and at sea level, I have the lid on and at 4000+

[Giz400ex]

Then call LRD and they will tell ya what you gotta do!!! There very helpful!!

[cals400ex]

the higher the elevation, the smaller the jet you use.
leave air box lid on, the smaller the jet you use.

i have a feeling they will tell you to use a jet a little bigger than what i said, but i think most companies do. sparks will say keihin 155 with air box lid off, aftermarket filter, x-6 pipe, at sealevel. the higher you go on jetting, the less power you will have unless you "need" a larger jet. however, you do not want to run it way small either. good luck

[cotttonwoody]

Ok I understand now. I was thinking the higher the evelation the bigger the jet. Too bad i ordered $30 worth of larger jets. Thanks for clearing things up. Anyway i went ridding yesterday and found out the 152 was too rich, so i took the lid of and it ran fine.