A few years back I had an 04 Z400. Spent some time working on it but it was stolen. I decided I missed the quads so I got a new one. This time I wanted to go used (no payments). I already played the Suzuki game and wanted to give a honda a try. Love the look and it finally has reverse (the only reason I didnt buy Honda the first time). I do trail riding with little mud and no sand. I have heard this is slower than my Z was but Im looking for a sound trail machine not a race quad. Now for the needed help...

I just picked up a 05 400ex. It is running a little rough so Im going to tear apart the carb, clean it and rejet. I noticed the air filter is nasty. I am going to replace it with a new one and leave the air box lid off. Also it already has a wb e-series slip-on pipe with I believe all silencers intact(?). The guy I got it from says the jets are all original. I need to know a good starting point for rejetting. Or am I better off leaving them stock? Im in Nh and the temps are dropping, Im guessing I will need to consider that in the decision. Any tricks or tips in this process? Also Im new to the wheeler carbs so any input on the jets, how many there are, and what each does would help. It seems to start very hard (cold blooded), once it's running its fine but seems choppy in the uper rpms.

 

i got an 04 model and i just bored mine to a 416 and they recomended me to go up 2 sizes , stock is.038 and i went with.042 , my brothers was rejetted & if u touched the throttle when u tried to start it it would foul the plug , but his also had the choke removed (they said for quicker throttle responce ) but i dont know bout that