No...if the fuel is running out the drain on the bottom of the bowl, then the drain screw id not seated all the way...you could swap the bowl cover from a new carb to the old carb to see if that works...but I can see your point if you're at your wits-end...

 

Don't be surprised if the shop replaces that aftermarket petcock and fuel line...the volume coming down to the carb (pressure) is more likely greater than the float is designed to hold back...I believe that's the simple fix...as you know...the fuel flow is stopped when you seat it manually...so the seat is good...I'm pretty sure there is just to much fuel pushing down on that seat for the float to seal it...


And that's most likely my issue as well, as I also have an aftermarket petcock on my boy's LT80...

 

The fuel is going over the top of the tube in the fuel bowl with the original carb which is what started all of this. On the new carbs it fills and then runs out of the carb as I said. The petcock and new fuel line are identical(in diameter and size) to the original and as I said, all the issues started with OEM equipment when the fuel is so high it runs out the fuel bowl overflow tube. I even put back on the original petcock and fuel line with identical results. The one thing that I just thought of but no idea if it is relevant is that when this started it would pop and sputter then take off and run perfect and then die.I pulled the fuel line and nothing was coming out which is why I bought the new petcock. I drained the fuel tank and it looked clean and fine. Is there anyway that I get a vacuum and then pressure in the tank, which is what is happening.I know it is gravity fed but something is causing vapor lock and then pressure I tried without the gas cap just in case. As far as I know the only vacuum off carb is to rear brake(I think).I hate giving in....

 

The tanks are vented...if that vent was obstructed then you'd have negative pressure in the tank and the result would be fuel starvation...

 

So...just got done reading about 10 posts from various forums all about your situation (same machine) and there were 2 solutions:


1) float needle seat clogged
2) adjust float tabs to have float needle seat faster (less fuel in bowl)


one post said this started happening after dealer rebuilt his carb...


One way to ensure it's not the petcock is to open it partially (reduced flow) and see if you still have carb overflow...if it still overflows then your issue is 1 or 2 above...

 

Spent the last 4 hours working on the wheeler. I ended up putting the original carb back on after disassembly and cleaning again. It runs absolutely perfect if I shut off the fuel when done riding but that really hasn't fixed the issue. I will admit it wouldn't run at all before, so cleaning jets and seats helped. I just can't believe the other carbs I bought absolutely would not function either and that all 3 carbs did the same thing except the original one had the gas go over the overflow tube and run out and the others went in airbox and head. I have done a lot of stuff and built several street rods in my 60+ years and this makes no sense. I will just do like you and remember to turn the fuel off and on when I want to ride. Thanks

 

LOL...yeah...I've kinda given up on my son's atv as well...and you wonder why everything is going to EFI

 

I recently got a untrasonic cleaner...I used it on my son's clean carb and was surprised how not-so-clean it was...hoping that helps...

 

I took the carb off againand used my Dremel polish attachment on the fuel needle seat(carb cleaner would not break down the varnish) and that was all I needed. No more leaks and runs great again.

 

yeah...clean, sometimes, is not clean enough...glad to hear it's all sorted out...