I own a 2000 400ex, which i bough used and every time i do a wheelie gas just poors out of the over flow tube from the carb. The 400's have no adjustments on the floats (their plastic where it's usually a metal clip to bend). I slowed down most of the gas porring problem with a screw, however this is hopefully just a temporary fix.
I also have a dg silencer, and k&N power package kit and i've been noticing with the cold weather and all that it back fires and stalls frequently, is this fixable by increasing the jet size?

PLEASE HELP

 

I beleive this is normal,if anyone know's that is not normal I could use some info on this topic also as my rubicon does the same thing while doing wheelies.

 

isnt that just your carb overflow? i do believe it is... could be wrong though i think its just because of the way the carb sits during a wheelie, im sure its normal both my quad and my bike do this no worries

 

Yeah thats just your overflow. Completely normal. As for the backfiring,sputtering, and stallin, with this cold weather the air is less dense so you would actually have to go down one jet, you're runnin a little rich. When you go down one, you'll notice that the amount of overflow will decrease a lot too.

 

Yes the gas coming out the overflow is normal but if you plugged the hose with a screw take it back out. The overflow hose also acts as a bowl vent. This can cause some of your negative effects you describe. You could try a new needle and seat and float which may help to slow the run-off but only if they are leaking from being worn.
Also if you have installed a K&N filter you probably do need to rejet. Not leaner though ....Richer for two reasons. One being that the K&N flows better than a stock filter and two..cold weather requires MORE fuel not less to run properly. Rejetting will not affect the amount of fuel run-off though.
Good Luck and Happy New Year

 

<< cold weather requires MORE fuel not less to run properly. Rejetting will not affect the amount of fuel run-off though. >>



Oh... my mistake. I'll double check my answers before I reply next time. Sorry about that. My friend had a 400ex that ran to rich and Gas would come out of his over flow when he parked it after riding. If that wasn't from it being to rich than I don't know what it was.

 

Not a problem! The gas running out after a ride (then shutting down) is caused from the heat of the motor expanding the gas in the carb.
(Commonly known as boil over) Since it has nowhere else to go when it expands, it has to be pushed out of the vent hose. As far as the jet size it only meters the amount of fuel going into the engine, it wouldn't have any effect on what is pushed out of the overflow.