[WillCRF]

My son's '02 XR100 is leaking fuel from the drip tube connected to the float chamber when the engine is at idle speed. You can see fuel dripping on the ground. The engine starts and seems to run fine. I noticed the plug was fouled which indicates a rich mixture. Does anyone have any ideas where to look first? Thanks.

[crfsonly]

my guess is the float needs to be set correctly.

[WillCRF]

crfsonly,
Thanks for your suggestion. I actually suspected the float height to be the first thing to check. Is this something I can measure by removing the float chamber bowl without removing the carb from the bike? Thanks again for your help.
Will

[gincognito]

This is an old thread but my advice to anyone having this problem is to replace the needle valve. I had the same problem on my DRZ400 and I dickered around with the float, cleaned the carb, etc. etc. I must have taken the carb out three or four times (a pain). Finally, I changed the needle valve and the leak was gone immediately.

[WillCRF]

Actually this was a float issue if I remember. I simply removed the carb, took the bottom off and cleaned the float chamber. Must have been something messing with the float because this did the trick.

Will