carb question

Today I installed new carbs on my 1986 xl250r (dual carbs), It starts right up and runs great but when I cut it off a whole bunch of gas leaks out of the drain tube. It never did this with the old carbs on it and I put an identical set on there and ran all of the hoses the exact same way. Does anybody out there have any idea as to why it might be doing this.


86 xl250r

it could be the needle valve is not closing , this is the pointed plunger looking item with a rubber looking tip, the usual causes are worn rubber tip, crud in the valve seat, wrong float level, float can be hung up or full of gas .

The general cure for this is first to determine if the needle valve is closing, you'll likley have to remove the carbs, remove the bowl and flip them upside down. Get a sm piece of hose and connect to the gas inlet of the carb, blow into this hose and actuate the float you should be able to stop the flow at some point,the point at witch it shuts off is the float level, this level should be parallell to the edge of the bowl, the tab on the flat is movable and permits a sm amount of adjustment. the float has to be set so that it closes the needle valve when the float is // to the edge.

The bike is not new so the needle valve rubber tip might be rock hard, its supposed to seal and with age the rubber may not be sealing.

Start with the float adjustment it should take care of alot of the overflow problems. It wont stop it if its really worn but it will give you a better idea of whats going on.

you can get these parts from your honda dealer or sudco if you need to get a new needle valve.


thanks for the info, i'll see what I can find out tomorrow


i have a 86 duel carb xr and mine doesn't do that the only thing i can think of would be your needle and seat need replacing and it is causeing it to flood cause they are just overflow pipes just put a carbie kit threw should cost about $50, also i was wondering if you could help me i havea spark problem on mine it won't spark what should i do

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