Engine Problems Please help

[ohsobad_chevy]

I have a 2004 Honda 400EX. I have a HMF full system exhaust and I am running a UNI air filter with the airbox lid on. When the engine starts, it doesnt want to idle and when i take off it will spit and sputter. I have put a 170 main and a 42 pilot in the carb, which is what HMF recommended. I know that the jetting is correct for my elevation, because i have done several plug checks and had mechanics look at it. I am curious to know if over oiling the air filter can cause this problem. Any help will be greatly appriciated.

Thanks,
Mat

[zeppelin]

yes it can especialy if you use motor oil on your filter, it will make it run noticeably richer. try cleaning it with some kerosene or denurtured (sp) alcohol to make sure you get all of the oil out and then ride it down the street without oil on the filter at first to see if it helps anyif it does you just need to ease up on the filter oiling

[Colby@C&DRacing]

try taking the lid off. Sounds to rich to me.

[ohsobad_chevy]

I use pj1 air filter treatment spray. I had too much of the spray on the air filter and it was not breathing good. I cleaned the filter really good and re-oiled it, but this time I didnt use too much. It fired up first crank and runs great!!

Thanks for all the input,

[400exrider707]

Definitely way to rich. I would NEVER listen to HMF's recommended jettings. I wouldn't even jet that rich if I had the lid off. Try like a 155 main, move the clip on the needle down one notch, and play with your mixture screw. The 42 pilot should be OK.

[ALLUWANT]

tune your bike by the end of your exhaust muffler. its really hard to tune a quad by the plug like u would a car. yea it sounds to rich id take off the lid but look at the end of the muffler it should be a charcaol color when u have it right. if its coal black then its to rich if its white then to lean