Carb problem, cylinder filling with gas when parked

[1993SSP]

I'm puzzled, my petcock on the tank works, turns the gas on and off. I turn it off each time I park the quad. Sometimes this happens, other times it does not. I will go to get the quad out and there will be a puddle of gas underneath it, go to kick it off and the kick locks up. I have to take out the plug and kick all the gas out of the cylinder, replace plug and it will fire up and blow a load of gas out the tailpipe. Anyone have any suggestions??? It is a 1988 250R.

Check your float level and adjust accordingly…sounds like it is out of whack.

Carlos.

[1993SSP]

I'm no carb person at all! How do I check it and adjust it???

Depending on the type & manufacture, a dimensional value for the float height exists. What type of carb do you have? If it a Keihin, remove the carb from the engine, unbolt the bottom bowl screws (4 plcs), set the bowl height based on the manufactures recommended height (I don’t recall what that number is, I want to say 17MM, however; you need to check for yourself).

While the carb is out, clean completely, inspect the needless, jets, slide, make sure everything is clean, no hairs, or foreign matter…

It is very easy; you will have no issues in setting your float height.

Carlos.

[1993SSP]

One thing that is confusing me is that the gas is turned off each time, is there that much gas left in the carb to cause this issue??


The carb is a keihin

The bowl does contain a small level of fuel, never measured the exact amount…

Your petcock could be leaking fuel through into the carb bowl as well. Regardless; cleaning & setting your carb to specifications is a good start.

Carlos.

[speedfreek]

Pull off the fuel line going to the carb. Turn petcock off and see if it is leaking.

When I park my bike I always run most of the gas out of the carb.

[JTRtrx250r]

some petcocks can be finicky, mine always wants that "optimal" off too...like it wants to be in the perfect spot or it'll have a real slow leak also

I rebuilt it a few yrs ago when it started seeping and its still finicky

[fearlessfred]

u can ck the level by removing the four screws from the bowl and then holding the bowlin place by hand and turning the fuel on for a minite and then remove .the bowl should be half full .when the bowl is on the floats displace enough area that the bowl is full to the top.the bowl is kept that full for good throttle responce.my guess is that the rubber seal in the petcock is breaking down and rubber parts are getting in the needle and seat ,not letting them seal completly. i have never known the float level to change on its own except for old brass floats that get a hole in them and sink

[86 Quad R]

as mentioned, it sounds as though the float is either out of adjustment, there is trash getting between the needle and seat, the needle is bad or the seat itself has gotten built up with funk and needs a good cleaning.

as for the shut off valve.... over time the rubber will get dry and start to deteriate or get funked up with deposites, allowing fuel to seep past. the rubber can be flipped over and reused in most cases. however, generally apply a bit of petrolium jelly on both sides(prior to re-assembly) to soften the rubber.

something doesnt sound right in regard to it filling the engine with fuel. the only other time i've seen this is when, either someone had looped the vent hoses wrong or the over flow tube in the float bowl was partially or totally clogged.

ps:this is a good time to completelt go through the entire fuel system and make sure its good and clean. including the tank aswell as install an inline fuel filter if you dont already have one.

[3racers]

I always drain the carb if it going to set more than 3 or 4 days. Gas these days is bad with ethy in it it gums up carb. quick.

[fearlessfred]

Originally posted by 86 Quad R
as mentioned, it sounds as though the float is either out of adjustment, there is trash getting between the needle and seat, the needle is bad or the seat itself has gotten built up with funk and needs a good cleaning.

as for the shut off valve.... over time the rubber will get dry and start to deteriate or get funked up with deposites, allowing fuel to seep past. the rubber can be flipped over and reused in most cases. however, generally apply a bit of petrolium jelly on both sides(prior to re-assembly) to soften the rubber.

something doesnt sound right in regard to it filling the engine with fuel. the only other time i've seen this is when, either someone had looped the vent hoses wrong or the over flow tube in the float bowl was partially or totally clogged.

ps:this is a good time to completelt go through the entire fuel system and make sure its good and clean. including the tank aswell as install an inline fuel filter if you dont already have one. or maybe one of the vent tubes are hooked to the overflow. i say this because, he stated that there is a puddle of fuel on the ground and the crank case is full of fuel