Got a 2002 with 376cc engine..auto .carb started to overflow so replaced the float needle and adjusted float...still doing it once in a while.The seat doesn't look like it's replaceable..........has anyone replaced this seat ..or do you have to buy a new carb..it is a Keihin...manual doesn't show this part as replaceable.

 

Looking at the exploded view on Babbits site it looks like the seat is not replaceable. The valve has a rubber ring, the seat should be smooth with no scratches. Inspect the seat under a magnifier. I would think a polishing compound would remove and damage but your going to need to flush it good. 00 steel wool may work also, careful, you need an even bore to correctly seat the needle valve.

Mine well leak also, I am wondering, should the gas be turned off when not in use. I know my tank is vented as it spews gas when it is upside down on top of me. A vented tank has little pressure. I can see it leaking out the cap. Maybe just turning off the gas well do the trick.so gravity pulling the fuel through the system may be the culprit.

 

After I posted,got my thinking cap on...Got a Q-tip and put some valve grinding compound[fine grade]...worked it round and round and up and down till it was allshiny in there.Havent tried it yet on the trail...yes I always shut the gas valve off when not in use or transporting.Does having a quad upside down on top of you occur often?.....lol..Thanks for reply..

 

Only when I trail ride.

 

Same problem on my 454. I have to shut the fuel off if I am not driving it for a while. This will sort the problem out. A buddy of mine fixed his problem by using a non-vented gas cap and putting a thumb valve in the cap. He opens the valve when he starts the bike and closes it when he's done. This doesn't sort out the problem but is a solution that works.