gas drip from 1971 yamaha at bottom of float cover need answer

[stinker711]

i have a yamaha 250cc dirt bike 1971 not sure of make but at the bottom of my float cover there is a small drain or breather with a 7 inch line attached to it does anybody know where the other end attaches to. it just keeps leaking gas. need some advice thanks stinker711

[mad_biker]

That hose is an over flow hose.it allows gas to drain out of the carb when you lay the bike over instead of the gas flowing into the engine and flooding it.it should not leak when the bike is standing straight up or leaning on the side stand on level ground.the first thing you need to do is take the carb off of the bike and remove the 4 screws from the bottom of the carb.tap the bowl with a screw driver handle a few times to loosen it.remove the bowl.after you take the bowl off you will see the float.when the float move upward and pushes a needle upward and stops the flow of gas into the bowl.when the bowl starts to empty the float goes down and the needle goes down also allowing gas to flow.it sounds to me like the needle is stuck in the open position.you can fix this by removing the float and cleening the needle and needle seat (the part that the needle slides into) spray a little wd40 on the nedle to get slick.put the float and bowl back on and hook the gas line back up turn the gas on and hold it uright.if it doesn't leak the try tilting it side to side slightly( if you tilt it to muc it will leak,this is normal).this should fix your problem.

[ossagp]

What Mad is leaving out is that the float should also be checked to see if it is properly adjusted. Float adjustment even on the newer carburetors is something that should be checked regularly, and at least seasonally to keep any machine running sharp. The guys you see on TV winning races have it done before each event at least.

Faded put up a post which is in the knowledge archive with good pictures showing the way to check it. I would suggest doing that when you are done with what Mad tells you, just before putting the float bowl back on.