Do I need to re jet my trx400x

[Cmiyler95]

I just got a 2012 Honda trx 400x and I want to put a fmf power core 4 slip on exhaust on it and a k&N air filter. If I do this will it need to be re jetted.

[TheAwesomehonda]

Yes you would have to rejet. probably 42 pilot and 160 main but i'm no expert.

[HondaRacing83]

where are you located? i got a 42 pilot with a 152 main and i have a motoworks slip on and uni filter

[2001400exrida]

lid on or off? go up to a 155 main, u can use the stock pilot that's not always mandatory, but if it's starting hard or popping on decel go with the 40 or 42 pilot.

lots of guys suggest going to a 42 pilot with just a slip on and that's a little overkill, when i put a 42 in with my lexx pipe it would flood itself out at idle.

[JOHNDOE83]

90% of the time exhaust manufacturer's reccomend a 155 main jet just to use their slip-on.

If you have a 2012, I dont reccomend removing your choke yet. Generally we use a 42 pilot when we remove the choke on the carb for a lil performance gain. The 42 pilot allow's it to start all the time in any almost any weather to start normally without use of a choke.

155 or 160 will be good jetting for your slip-on, you might be able to turn the a/f screw out some to compensate for popping and backfiring after the mod. If you turn the a/f screw more then 3 turn's and it still pop's, get a 42 pilot jet.

I havent seen a 2012 carb, you may need to get the "D" shaped tool to adjust your a/f screw if it has that instead of a flat head.