The bowl had dirt in it around the needle/seat area, so I replaced those along with the other goodies in the fuel bowl. It will start up pretty easily now, but as soon as I give it throttle it wants to stall/backfire.

I know there are 2 adjustment screws; The one for the idle speed which is on that flexible cable, and the mixture, which is the harder one to get at, in front of the fuel bowl, straight up from the bottom.

Don't know if I don't have that one adjusted correctly or not, seems every setting I try doesn't really improve things much. Barring that fact that there might still be some dirt in the carb passages, what do you guys suggest?

Bottom line, it will start easy enough, sounds good at idle, but stalls/backfires when I give it throttle.

 

The air/fuel mixture screw is the one thats harder to get to. I just went out and looked in the shop manual, and couldnt find any specs on it. I'd take a guess and say 3 turns out would be about right for stock. I can't remember what it was, but I think I have mine at either 3.25 turns out or 3.5 for the larger jets and HMF exhaust, and I believe it was right around 3 turns out when it was stock.

Worth a shot if you havent tried that setting yet, but it could be something entirely different thats wrong with it. The float needle has been sticking on mine lately, and probably needs replaced. Sticks if I dont ride it for a month or so. After taking it all apart a few times, nowdays, I just pull the fuel line off and blow air in there to knock the valve back down into place. Quick fix, but doesn't really solve the actual problem.

 

Thanks for the reply. When I reassembled it, I set it to 2 1/2 out. I have tried adjusting back & forth, but doesn't seem to make much of a difference. I will work at it more tomorrow, maybe I will get lucky.

The thought of dragging this thing in to the shop doesn't excite me, as I was trying to DIY on the cheap...

 

do you have a new spark plug in it?

 

yes, new plug.

 

I'm having the same problem! Just replaced the needle valve (was frozen) and every time I give it a little gas - popping and skipping! Idles really good -If I recall the screw you guys are referring to only adjust the way it runs on idle?? I'm thinking we both both have gotten the main needle out of wack - Please somebody help us both - this is my fathers 4 wheeler and I would like to get it fixxed and out of my garage and get "my" toy back - 1962 vette!!!

 

Kind of sounds like it is going lean real bad. I thought that screw at the bottom was the idle mixture. Could a piece of dirt dislodged and gotten clogged in something? Did you set the clip etc exactly the same? Could the float be a problem. An almost empty bowl could lead to that kind of problem.

 

Hey up2nogd2,

Do you suppose that you might have inadvertently sprayed some carb cleaner in the vacuum hose area where the main needle is? I think that I did, & I am wondering if this may have contributed to my problem here.

I will pull the bowl off later today & check things out again. Hate like heck to have to remove the carb & disassemble it again, as removal is a major hassle...

I think it is safe to say that the problem lies in the mid-circuit, or running circuit as opposed to the idle mix. Mine will start up easy & idle fine all day.

Still wondering if there is some dirt in the mid-circuit that I might have stirred up during cleaning, because it was running just fine prior to this, except for when it wasn't getting gas at all & the bowl was empty because of a clogged needle/seat.

 

I guess I could have? Yea - what a pain in the %$# !! I have taken mine apart 2X and am still having the same problem. Hopefully someone here will shed some light on what might be going on. PLEASE!!!! I really do not want to take this thing into the shop. It might just be easier and cheaper to buy the edlebrock replacement carb!

 

Yama,

It must be something easy to miss since we are both having the same issue after clean/rebuild? Mine does exactly the same thing - starts/idles better than new - give it a little gas and snap, crackle, pop!!