My float needle keeps getting stuck in my carb; fuel leaking out overflows.

[caesius]

This seems to happen every other day, I'll get back from a ride and fuel starts running out the overflow pipe. From what I know this means the float needle is stuck but I cleaned the carbs about a week ago so why would this be happening?

In the meantime I remedy the situation by turning the fuel tank to OFF and running the engine for a bit. Then I turn the tank back ON and it fills the carbs' bowl and no leaks again. I'm frustrated.

[bistard]

Have you removed the floats & checked the condition of the needle & seat,
if they are damaged or worn,will give you the same symptoms,also make sure the float height is ok & float moves freely

[caesius]

Cheers bistard that's the prob, I took the carbs apart and everything's sweet as (I've got "non-sweet" pics to compare to) the only thing that I can think of like you say could be the float height.

[idb]

Look for a hole in your float, it could be filling up with gas and sinking after a period of time.

[scumdog]

Look for a hole in your float, it could be filling up with gas and sinking after a period of time.

True, I've had that problem before.

And each time I adjusted the float level it was O.K. for a week or so until the float filled with some more gas and sunk a bit.

[Ixion]

Does it ONLY leak when the bike is sitting after a ride? If you turn the fuel on and just wait does it leak? If Yes, No, then it may just be fuel expanding with heat.

A two smoker engine gets hot, and so do the carbs. While the motor is running the fuel is going through the carb fast enough that it doesn't have time to heat up. But if you stop, the motor is still hot , the carbs are hot, the fuel in the carb bowls just sits and gets hotter . And expands. That's why the overflow tubes are there, they have a purpose.

Alternatively vibration may be making the needles not seat well, when the motor is running.

[paturoa]

when you've done the cleaning was there any crap in there? If so go get one of those inline fuel filters.

[caesius]

Does it ONLY leak when the bike is sitting after a ride?

It appears to be completely random.

[Ixion]

In that case you either need to replace needles and seats, or, if they be brass, lap them in with metal polish and elbow grease.

[idb]

How'd ya go?

[Guitana]

I had this some years ago came out from work to find precious bike juice running into the gutter!!!
Nothing a new set of needles and seats won't fix!!!

[caesius]

I'm at Uni now, staying in a hostel, and the b*stards have locked me out of the garage where my bike was! (their garage has changed ownership apparently and they can't give me an access card till...they don't know :angry: :angry: )

So at the moment I have no way of doing any tests. I'm probably gonna take it into Wellington motorcycles, how much do you think for new needles and seats? The carbs are Keihin PWK 28.

[F5 Dave]

Wow you must be rolling in money.

Make sure you take the jet actually out rather than only the needle & see that there isn't any hair behind it that is getting stuck.

Think the 28s have a brass jet. Try dropping a small ball bearing down the jet & give it a smart tap with a hammer/centre punch to make sure the sealing surface is round.

[Duc]

Does your carb have a valve on the base of the fuel bowl that allows draining water/fuel through the small hose attached?

Is it tight ?

[caesius]

No valve, just a screw plug. I can see it leaking from the overflow hoses so I know where it's coming from, just not why!

[Duc]

Try tightening up the little screw plug. (Its a valve that drains water or dirty fuel from the carby bowl).
What sort of carby is it? - Mikuni?

[caesius]

Try tightening up the little screw plug. (Its a valve that drains water or dirty fuel from the carby bowl).
What sort of carby is it? - Mikuni?

As mentioned before they are Keihin PWK 28's.

Thanks for the suggestion but I really can't see how this would help. Are you suggesting fuel is leaking out of the screw plugs?