Lots of good advice here. Even if you replace the tank and the carb you have to thoroughly clean out the lines (I replaced mine) and disassemble the fuel pump and clean it out, even if it is new. Also add a fuel filter that you can see through to see if you missed anything.

Finally here is an old school chart that will help you per Fred's recommendation:

 

I agree with many others. Before doing too much troubleshooting on your carb, I would get your gas tank replaced. If you haven't done it already, I would even replace the fuel lines, and maybe even the pump. I had the same problems. I took my tank out, dumped out maybe a couple of pounds of rust and crud in it. Took it into a radiator shop for cleaning and re-lining. That was a couple of years ago. But now I am starting to see small bits and pieces inside the fuel filter again. I am thinking Ethanol in the fuel here, is eating the lining off the insides of the tank. It's hard to find non-Ethanol gas around here. Ethanol is a good cleaning solvent. Looking back,now I wished I would of just replaced the tank.

 

I really appreciate all this detailed input. I think I'll just go ahead and get a new carb and tank and see what happens. Drained the tank yesterday and the last bit of stuff that came out was pretty disgusting, so I'm taking the tank out today, and ordering both items. I'll post again with the results.

Thanks again, everyone.

Ed

 

If you're as cheap as me and have time, I highly recommend electrolysis. Only removes rust and is nearly labor free. You let electricity do the work.

I successfully cleaned my tank and it was BADDDD...having been neglected for years. It took a while but it finally went back to bare metal. I didn't coat it but try to keep the tank as full as possible to minimize rusting. But if it gets bad again, I will probably just pony up a couple of bills and be done with it.

 

Problem solved! I bit the bullet and bought a new carburetor and gas tank, installed both, and it runs like new. Before I put the new carb on the truck I noticed that it took a LOT more force to push the pump rod in than it did on the old one. Also the butterfly shaft on the new one is tight, while there was (just a little) play in the old one.

Regardless, it is nice to be able to actually use the idle speed and mix adjustments. Next problem, which is minor compared to what I went through with the carb, is that something keeps slowly draining the battery. I'll do some checks, search the forums, and then start a thread on that if necessary. Anyway, thanks to everyone for the information and suggestions on the rough running/carb/gas tank dilemma.

Ed

 

Excellente.. Should be purring like a kitten