Guys I am in dire need of help. First let me tell you I have a race Sunday and have to have this problem fixed by then. Here is what is happening:

I had a race last Sunday and it was a very very wet race, my quad didn't run right after the first lap and would cut out bad when ever I attempted to rev it high. Now this is a week later and every time I do a wheelie or get on it the quad starts backfiring and just dies, if I let it sit for a second (not long) it starts back up and runs. It will sit there and idle forever without a hiccup but will not take a wheelie at all and high speeds cause it havoc. Now the absolutely odd thing is that my buddies 400ex is doing the exact same thing and we were both at this wet *** race. Now before the race the only thing that we did that could have caused a problem was we removed the front plastic and electrical connections and tank. Has anyone had this problem before if so or anything tell me. Also we cleaned the carb from top to bottom and tank and all connections. Oh yea when the bike comes down from the wheelie it is running so bad that it backfires flames and just coughs and sputters. We even put new gas in them. This is driving me nuts, help guys.

Thanks in advance

 

It sounds like your overflow hose for the carb is plugged, probably with mud and/or grass. The flames and backfiring are from the engine running way too rich, the carb needs to vent fuel when wheelie-ing and flying around at high speeds, if it can't, the engine gets flooded with fuel.....

Stand the bike on end, you should see fuel spill... Double check all overflow hoses coming out of the carb and I think you'll find your problem

 

my buddies 2000 was doing something similar.
His would idle fine,and run smooth but would not rev at all. He took it to the shop and a pin was out of the slide in the carb. Thats what his dad told us.(he took it to the shop because my buddy has to work during shop hours) His dad's description was a little vauge,but it runs fine now.took the shop about an hour to fix. Hpoe this helps.

 

you said it was wet, so drain your gas in the tank
and the carb and put new in it.

 

TL,

Here's another thing you may want to check out. Someone had a post in here a while back, but I couldn't find it. I am not too good at finding old postings. Anyway, this person had a real problem with his machine running correctly. If my memory serves me correclty, it was similar to yours. I am being real vague because I couldn't find the damn post. Once he took it to the dealer, it ran fine. They told him his Ignition Coil was dirty and that it needed to be cleaned. That was it. You wouldn't think this would be a factor, but it was. Apparently, they even stated that Honda really picked a terrible location for the coil, which is just under the gas tank behind the front fender where all the dirt and water cover it. Try cleaning it (don't exactly know how you clean the coil, but clean it the best you can like the dealer would), at least once you do this, you can rule it out as a cause. Hope this helps.