Lesson learned

[squidchief]

My sons dirt bike started leaking fuel out the rear carb vent. Turned off the petcock but the fuel kept flowing.
1: Bought a petcock re-build kit. Not too spendy, easy to install. Old one didn't look bad, but what they heck.
Talked to a couple of people and they suggested adjusting the floats. Didn't make any sense to me as how would they of gotten out of adjustment if the carb hadn't been monkeyed with.
2: Removed the carb and gave it a good thorough cleaning. Re-installed.

Still leaking.

3: Bought a carb re-build kit. Cleaned the carb again, installed re-build kit. Some of the old O rings didn't look so good. Re-installed.

Still Leaking.

4: Scratched head for a while. Drank some beers... scratched some more.
5: Removed carb. completely disassembled again. Cleaned again. Bent the tab a bit more on the float to adjust it a bit. Everything checked out fine on the blow test. Re-installed.

Still Leaking. REALLY????? DAMNITT!!!!!!

6: Time to go back to the store.... bought more beer. On a side note, the Sam Adams Winter collection was quite nice. The "Double Nut Brown" from Mammoth Mtn Brewery, not so much... A couple of racks of good ol PBR's re-stocked my shop fridge. Time to sit back and watch some football.
7: Had a buddy come over. Removed and disassembled the carb. Getting quite good at it. Running carb cleaner spray through it we noticed a couple of small pieces of crap, smaller than grains of sand, come out of the floats needle seat. Re-assembled.
8: Installed a small screened fuel filter between the petcock and carb. Re-installed carb.

Still Leaking!! #!$&&^**$#*$#+#^*!!!!!!!!!!

9: Removed Carb. Disassembled. Cleaned. My buddy gently sprayed carb cleaner through all the orifices again while holding the carb over a white paper plate. Again, found a couple of little pieces of crap come out from the float jets again. really??? Where the hell did they come from??? I could eat off this thing it's so damn clean. Re-assembled. Man, I can do this little task blindfolded anymore.
10: Drained some fuel from the line to ensure no crap left after the filter.
11: Re-installed carb. I can do that little job in less than three minutes now!!!!

No Leak!!!! Small idle adjustment.... No Leaking!!!!!

DONE!!!!

What did I learn through all of this.... besides that I don't care for Mammoth Mtn Breweries Double Nut Brown beer?...... I often see on here where someone has pulled and cleaned their carb and they are still having carburetor problems. A small dirt bike carb is a lot less involved than one off a Shadow. Little crap can hide. Also, where did the crap come from in the first place? Probably a bit from the bottom of the gas can got into it last time fuel was put in, If I had installed the filter right around step #2 and then flushed the fuel line before re-assembling I probably would of never gotten around to needing steps #3 through #11... well except for step #6. Seems I'm always needing beer in my shop fridge.

If all the evidence points at something, even if you've checked it once or twice... it might not hurt to check it again. Having my buddy come over and show me to lightly spray cleaner through the carb and capture what comes out was also beneficial. What was to of been a simple job ended up not so simple, but it got taken care of and I didn’t have to pay anyone to work on it... well, payment in beer never counts, right?
Bike will get its final test run this afternoon when my son gets out of school but I'm thinking this project can be crossed off.

Now to get the rear end dropped out of my '68 and get it swapped out and then put it on the market to get it sold....... Better pick up more beer!

[GrumpyOldMan]

Great story! As you prove, there is no substitute for careful and thorough cleaning of carbs and fuel systems!
I remember a car my Pops had that did something similar - ended up being a small rock that somehow traveled from the fuel tank, through the pump and into the float bowl. Everything was fine until you went over some bumps, then this teensy rock would plug the float valve! We were real lucky the extra gas didn't drip onto the exhaust manifold or pipes before we found the problem!

[CavemanBen]

I've cleaned my vlx carbs upwards of 8 times before I got it right. A lot of shops drop them in an ultra-sonic tank over night to break stuff lose. If I had to guess id say your issues started with a stuck open needle valve