I rebuilt my carb and got it running for the first time a couple of weeks ago. It's never been street legal yet so I've only had it on the dirt back roads. It has a 350 in it now, no comp. no emissions, I replaced the mech.pump with the type with a vent return to the tank. It ran ok for a while, then it started flooding bad, won't idle at all just dies and will countinue to push fuel into the carb and into the cylinders. I took the fuel cap off and it had a lot of pressure. I took the carb off to see if it was cloged up in the float valve, nothing. put it back and pluged the pump return vent line to the tank to see if it was over pressurizing the tank and forcing fuel into the carb forcing up the float valve needle. Tried it and it still floods, even out the pumper rod. disconnected the fuel line so I wont have to take all the plugs out and turn it over and change the oil again. that was yesterday, now I'm about to go back out and check it again before I take it off. I hope I didn't blow out a valve seal or something? and if I did. Did plugging the vent on the pump help it, and I just need to fix the carb now? again! Any idea's or suggestions.

 

You've got dirt in the inlet valve (it only takes a tiny speck) OR the float is hanging up on something.

To flood out a Qjet THAT bad from over-pressure you would need more than 15-20 PSI. Hook up a fuel guage near the carb temporarily to check for sure.

I suspect you jiggled some dirt loose in the fuel lines wehen changing pumps or when you simply disconnected the fuel line to rebuild the carb.

Are you running the correct fuel filter in the nose of the carb? Did you reinstall the spring that goes BEHIND the filter (in other words, you put the spring in FIRST and the filter on top of it)? It keeps the filter sealed up against the fuel inlet. Put 'em in in the wrong order or don't install the spring at all and you are getting unfiltered fuel into the carb.

I usually jsut ditch the stock filter and install a nice in-line see through filter just in front of the carb. Easier to see when it gets dirty and easier to change.

 

I took the filter out and put an in line filter just before the carb. It is parked on a slight angle/***** , just enought for the no. 2 cylinder to get fuel in. I didn't mean all, but I wasn't going to take any chance's, so I changed the oil. The carb was still flooding but after the third time checking and cleaning it stopped. I couldn't see anything so you were right about a tiny bit of something getting in there and sticking open. thanks for your help, time to go get this thing legal and burn up some back roads!