Wow. Okay. If your carb leaks fuel, simple rule: You're getting too much fuel.
This can be caused by the following:
1) Float valve stuck
2) Jetted wrong
3) restricted air cleaner (causes a "choke" condition).
First of all, stop the leaking. Make sure your vents breathe (cap vent works?).
Check the float level (see above post about how float will be level if carb is held upside down with the bowl removed).
Make sure there is no obstruction in the float valve passage (dirt can cause the float valve to stay open). Make sure the float valve is clean, not worn.
If that is good, and the float is level, you should never leak fuel from the carb unless the bike is upside down. If it leaks, then your float's not working.
The air/fuel screw (if the bike is equipped) is only for idle mixture. It does nothing at higher RPM. Only adjusts the idle air/fuel.
A screw about 1/4 way up on the side of most carbs is "IDLE SPEED". It physically limits how far down the cylindrical slider rests in the carb. The lower the cylinder, the more restriction, and lower the idle speed. Turn the screw in (clockwise) to raise idle speed.
A screw on the side, near the base of the carb, usually at an angle is the air/fuel. This is for idle mix only. If the bike is missing at idle, you can sometimes tune it in with this screw. If you can't, or the adjustment makes no difference, the idle passages are dirty or the idle speed adjuster is set wrong (either too low, doesn't run, or too high, revs beyond idle range.)
If the bike runs like crap at higher RPM, or backfires, then the main jet is either dirty or the wrong size.
YOU GOTTA BE WILLING TO TAKE APART A CARB AND CLEAN IT RIGHT.
Take it apart, take photos, make drawings, take notes, etc to make sure you can get it back together properly. Don't turn screws in like a maniac with a fat screwdriver till you bottom out the screws and damage the seats and needles. Take it easy. No use spending $300-400 on a new carb cuz you monkeyed it to death.
Clean everything with carb cleaner. Carefully blow out the needles, jets, and passages with compressed air.
Reassemble the carb and adjust it to spec. Gently bottom out the air/fuel screw and back it out 2 and 1/4 turns or so. Then turn on the fuel, see no leaks, be proud.
Start the thing, adjust the idle speed, and adjust the air/fuel.
Sounds like a pain in the butt, but how much time have you already spent on fixing it? And, so you buy a used carb for $40 on ebay, guess what... The dude your buying it from probably took it off a bike that sat for 3 years with fuel in the carb. That carb will need cleaned too. So, you're just better off cleaning the carb right the first time.
Trust me, it's a pain. But it gets easier and easier each time you do it right. I used to send carbs to shops. Now I can tear down a carb and clean it right, adjust it and have the bike running in about 20 minutes or so.
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Originally Posted by traxxasx
