i have a 2000 warrior which just got the big bore 400 kit in it and i runs way to rich.
it fouls plugs everytime i ride it and now i cant even rev it. it puts out clouds of black smoke and the spark plugs are very black. and its not the valves because i just had somebody put all new valves in it.
how can i lean it down? should i change the jetting or should i move the E clip on the carburator down or move it up?
PLEASE I NEED YOUR HELP FAST.
THANKS FOR READING THIS.......

 

This is just jetting on your carb. There could be other problems in your head like Rings, guilds or valves. Here we go:

1/4 to 3/4 throttle is controlled by your needle. Clip down, raises your needle = Rich.
Clip up, lowers you needle = lean.

Full throttle is controlled by your main jet. Lean out by one main jet smaller at a time.

The reason I gave a caution at the top was by puting in a big bore kit, this should have leaned it out. Thick black smoke on a 4 stroke most always means a valve or ring issue. Look into this deeper.

I also remember an issue of dirt wheels stating that the pumper spring in the carb wasn't stif enough and they replaced this with a ball point pen spring. I have done this and it really works good. Once you tear your carb down, you'll see what I'm talking about.

Good Luck
NewDSLover

 

Well, having done a 400 big bore should not have made it rich, but lean. The smoke, I would be willing to bet, is the cause of worn valve seals. If the seals are worn already, being the quad is a 2000, I would check the valves for straightness also. I have had the piston slap the valves on my warrior a couple of times now. I am willing to bet that is your problem. If you increase the bore, you are also increasing the amount of gas you use, therefore causing it to run lean and needing a bigger jet to supply all the fuel. I put a new cam in mine this weekend and it was running sooo lean from that, 2 minutes just cruising around made my head pipe glow red. So, check that out because even though you are puffing smoke, it may be oil smoke from blow by and you may still be running lean and too hot.