Xr600 float leak

[Dans2444]

I have a 1988 xr600 that I bought with a leaking float,(bike had sat for 2 years) have totally cleaned and rebuilt the carb,replaced needle and float,checked the tube inside of the float bowl for leaks and it still leaks from the overflow. I took the bowl back off and inspected meddle and seat double checked float height (14.5 mm) and it still leaks so for grins I adjusted the float height to 18mm.  Same leak......whenever I take it apart and reinstall it won’t leak at first, but after I run the engine and shut it off after about 2-3 mins it leaks and continues to leak running or not.    Any ideas besides throwing a lit match into the puddle of gas?     

     Thank you 

    Dan

[Backwoods-Bomber]

I have a 1988 xr600 that I bought with a leaking float,(bike had sat for 2 years) have totally cleaned and rebuilt the carb,replaced needle and float,checked the tube inside of the float bowl for leaks and it still leaks from the overflow. I took the bowl back off and inspected meddle and seat double checked float height (14.5 mm) and it still leaks so for grins I adjusted the float height to 18mm.  Same leak......whenever I take it apart and reinstall it won’t leak at first, but after I run the engine and shut it off after about 2-3 mins it leaks and continues to leak running or not.    Any ideas besides throwing a lit match into the puddle of gas?     
     Thank you 
    Dan

Easy fix. The float valve seat gets pitted from the old gas sitting for long periods. Take a small wooden dowel and sharpen one end in a pencil sharpener. Apply a fine rubbing compound to the tapered point on the dowel and stick it in the seat and spin the dowel between your fingers. This will polish up the contact surface of the seat and usually solves the leak. Be sure and clean out the seat with a shot of carb cleaner and some compressed air before reassembly.

[S.O.A.N.Z]

so with the carby out - fuel connected - bowl off

fuel on - pushing up on the floats - does it still leak ?

Backwoods Bomber beat me to it - but yeah most cases its your needle & seat

[Dans2444]

9 minutes ago, S.O.A.N.Z said:

so with the carby out - fuel connected - bowl off

fuel on - pushing up on the floats - does it still leak ?

Backwoods Bomber beat me to it - but yeah most cases its your needle & seat

With carb off fuel on pushing float to seat the needle it does not leak    I will try the dowel and compound but looking it appeares to be very smooth and clean 

Just now, Dans2444 said:

With carb off fuel on pushing float to seat the needle it does not leak    I will try the dowel and compound but looking it appeares to be very smooth and clean 

Is the seat serviceable?

[Tmosely1]

I had a similar issue after purchasing a rebuild kit and installing it. Some of those kits do not have the correct needle valve. I pulled apart and cleaned my carb several times.. almost drove myself crazy. It would sit for about a minute and then start dumping fuel out of the overflow. I suggest the old school test... remove it.. clean it.. flip the carb.. and pull a vacuum on the fuel inlet. If it bleeds off in a couple seconds... you have a bad needle or a significant issue with the seat. My guess is you need an OEM needle

[mcma111]

Clean the needle seat with a PENCIL eraser

[Dans2444]

Thanks for all of the help and great ideas!  It ended up being a faulty needle from a cheap rebuild kit,I should have known better and just bought oem. I put vacume to the fuel inlet to find the problem(thanks to a helpful user) and it leak down immediately.

thanks again for the help everyone 

[S.O.A.N.Z]

2 minutes ago, Dans2444 said:

Thanks for all of the help and great ideas!  It ended up being a faulty needle from a cheap rebuild kit,I should have known better and just bought oem. I put vacume to the fuel inlet to find the problem(thanks to a helpful user) and it leak down immediately.

thanks again for the help everyone 

Was just about to send you a link to an OEM set