Hello I had just bought a 03 400ex and I have been hearing that alot of people are taking the chokes out and putting a 42 pilot in them and they will start right up in the winter and well i was wondering will it change anything in the summer and if I should do this to mine.Its stock besides a k&n filter no airbox lid and aftermarket exhaust tip


I also herd they came out running lean I looked at my spark plug and it was dry black like carbon or somthing I figured it would run lean with k&n filter, no lid and there is a aftermarket end cap on exhaust besides that i beleave its all stock can you guys help me out. Thank you

 

I would never do this, but that is me.

If you jet your engine to start right up without a choke it will be a mile rich when it's warmed up.

 

Has anyone here done that to theres

 

honda atv's run lean from the factory in order to meet the emission standards...so it really isnt as rich as you might think to bump up to a 42 pilot jet. That being said I have never gotten my 400ex be jetted quite right since I did my choke removal. I also put a slip on, k and n filter, removed the airbox lid, and threw a sparks 6 degree key on it. Yesterday I bumped up from a 155 main jet to a 165 and didnt notice any difference in how it ran. But as someone who has done every cheap mod out there in an attempt to make this quad faster let me give you some advice. If you find this quad doesnt have the snap you want...dont bother trying do the small stuff. It wont change enough to satisfy you. You have to do a bigger bore kit or cam to really notice a difference.

 

Well said above^ Listen to this guy.

Buy a header pipe and a silencer if you have the money... But besides that your pretty much better off to stay stock .

 

My quad is all stock and runs out great! I rode with 440 kits etc. and they are not much faster for some of the problems they have.