silencer

[dannyboy20]

i am looking to get a whitebrothers slip on silencer for my 400. Will i be able to run this without adjusting the carb because i have heard some people say they have to get it re jetted ??? And also can you make this silencer any quieter ?

[4TraxRider]

Depends which one your getting, the r4 or e series. You should rejet to avoid overheating and backfiring etc., and to get the full advantage of increased airflow out of the engine.

[dannyboy20]

so if i had the k and n jet kit put in it would be ok ?

[250EXking]

Originally posted by dannyboy20
so if i had the k and n jet kit put in it would be ok ?
:D yep and an k&n air filter wouldnt hurt either.:cool:

[dannyboy20]

already have the filter. Would the jet kit void the warranty ?

[310Rduner]

shouldnt.. you already done plenty of other more serious things than changing some Jetting! lol..

[drip]

It is cheaper to go to the dealer and buy a single jet for less than $8 than to pay for the entire jet kit that has to have an adapter to make the jets fit. I bought a 150 and a 155 main plus a 42 pilot jet (slow jet). The main jets are $4 to $7 and the pilot jet is $3 to $6 for the 42. It varies in price depending on where you get them. I want to let you know these are jets for the stock Keihin carb on the 400ex. I have the full White Bros. ProMeg system on my 400ex and I am running the 155 main and a 42 pilot with six 1 inch air vents in the airbox lid. Stock jet size is 148 main and 38 pilot. I hope this helps you or anyone else.

[dannyboy20]

ok well say if i get the k and N kit is it easy to install ?

[Texan32]

drip is right. Getting single jets from the dealer is cheaper. But, the advantage of getting to jet kit is that it comes with several different size jets (future mods....need bigger jets). You also get the DynoJet needle. Thier needle has a different taper to it therefore changing the flow rate of the fuel at different throttle positions

[dannyboy20]

ok so basically if i get a silencer i need to have the quad rejetted for it . if i go with th K and N will this increase horsepower ?

[250EXking]

Yes,

Not huge difference, but yes you will see some gains. check out your jet kit, it should have a dyno run for you. For really big HP gains, look into 416, and 426 kits with high compression and stage two cams. That should get you power you want.