poping through the carb

[DREWS400EX]

I just traded my 2001 warrior for a 2002 400ex with a white bros r4 slip and uni filter, I dont think it has bigger jets. I also ground down the header welds and run the rear clips on the airbox under the lid to raise it a little. When I barley rev the engine it pops through the carb. It also backfires when decelerating. Would a bigger main or pilot jet take care of my problems? I live in Illinois but dont know what altitude, if that even matters. What size jets would you recomend? Also is shell Rotela T 15-40 a good oil for the motor?

[DantheEXman]

Go richer on the main jet. prolly a 155. Then pop in a 40-42 pilot if ya want.

[DREWS400EX]

ok, thanks

[Sparks425Ex]

Yeah... Sounds like ya are a little Lean.. Bump up to a 155 or 158 main jet and stick in a 40 piolet jet so it starts a lil easier too....

[DREWS400EX]

Hey, I'm looking through the Dennis Kirk catalogand see keihin jets for p-series ,pj, pwk, pd series carbs. Which one is for my stock carb? And is keihin a good brand. Thanks for your help

[Castor-426ex]

i thought rotella t was used in tractors and stuff?


use honda oil if a syntetic isnt in it

[DREWS400EX]

Do I order a 21 or 22 series pilot jet? Does it help to remove the choke and grind down the little fins inside?