gas pouring out the over flow... 01 400ex

[Tommy 17]

would the float on the carb cause the gas to pour out the over flow hose??? my friends 01 400ex is dumpin gas out the over flow and i wanna know what to check...

thanks

[chrisc]

Yes if the float is stuck open the gas has no place to go except for the overflow or in the cylinder. check to make sure the cyl isn't full of gas . my friend put a jet in his DS-650 and tried to start it and it wouldn't turn over so We pulled the pluges and he turned it over and the plug sparked against the side of the engine and lit the gas as the cyl pumped it out . what a mess. lucky he had a hose handy before it did any damage.

[Tommy 17]

ok the float wasn't stuck... what else can this be???????

[Colby@C&DRacing]

There is either something in the seat blocking it from closing or the needle is shot.

[Tommy 17]

this quad was just bought used... could the needle jet be set to high up???? i never even thought to look at settin its on...


thanks colby

[JOEX]

Originally posted by Colby@C&DRacing
There is either something in the seat blocking it from closing or the needle is shot.
Just curious, what causes the needle to go? Or are you talking about the float valve?

Joe

[Aceman]

The needle rides on the float arm. When the float bowl fills to a certain level it pushes the float up, pushing the needle up against the seat. This regulates the gas flowing into the carburator. If the needle and seat are wore out, it can't seal and the float bowl fills with to much gas and overflows.

[chrisc]

I think he was talking about the (needle and seat) or also refered to as the float valve. all he needs to know is someting is letting too much fuel into the carburetor. weather it is a bad seal on the float valve (needle tip) or float set wrong, or dirt under the seat. it shouldn't be hard to find .

[2004TRX450R]

I haven't really seen it on 400Exs but check the O ring around the outside of the float seat. Sometimes they will go bad and the needle will seal but the seat won't. There is something wrong with the needle or seat what ever is up. Usually the floats themselves won't be stuck but the needle will be frozen in the seat. Somtimes you can smack the side of the carb and jar it enough to brake it loose and it will seal up fine.

[wilkin250r]

There are several small possibilities. It could be assembled wrong, so that even when the floats rise the float valve doesn't shut off the incoming fuel. The floats could be sticking, or there is a leak in the floats. (They would fill up with fuel, and wouldn't "float") Or the floats could be set too high. All these are not likely, but they are possibilites to check.

I imagine it is one of two things. The tip of the float valve could be worn, so it doesn't make a good seal. Replace the valve, you shouldn't need to replace the floats.

Or, more likely you have some small object (like dirt) sitting between the float valve and the seat. When the floats rise, the valve will close against the dirt, so it doesn't fully close. Give the carb a REALLY good cleaning, spraying carb cleaner through every fuel passage, both ways (in the direction of fuel flow, and opposite the direction of fuel flow) A can of carb cleaner is only a couple bucks, go ahead and use the whole can.

If you DO discover it is dirt, it can only come through the gas tank, and that means there is probably more dirt sitting in the tank. Get an inline fuel filter.