Hello everyone



I will try and make it as short as possible!!



I have a honda trx 400 ex 2005 for a year now and it runs perfect , every gear runs smoothly from closed to full throttle , no sputtering , boging or anything and she is stock , I did nothing to her except take the original exhaust spark arrestor out



But my problem is that my spark plug is so damn black !

Carbon fouled powdery black, the atv does smell heavy on Gas while idling also , and very rarely while trying to hold a wheelie at high rpm a shot of black smoke would come out sometimes !!



I think I need to rejet , my atv does not have an adjustable needle So I ordered a Dynojet kit which arrives next week ,



I was reading the instructions online and it says for my model to bump the main jet about 5 sizes up ,won’t this make my bike even richer , is this really necessary or should I just lean the needle ? Oh and to mention I have never touch the air/fuel mixture screw , could it be as simple as adjusting it that fixes my problem ?



I use the correct plug specified in the manual , I also read that riding at low speeds can carbon foul your plug , it’s that where I live atvs are road legal and I use it a lot around the village I live and I’m mostly at 0 to 1/2 throttle or a bit more , hardly at WOT



Like I said the atv runs perfect , no stuttering or bogs I just want the spark plug to look normal !