Every year when I take my F-2 out of winter storage it seems like it wants to put up a fight. This year it wants to be a pop corn machine, at least sound like one. It will idle pretty nice, and even rev up pretty decent. When I put it in gear it will start OK with a little pop out of the carb but gets a lot worse as I shift up the gears. Just keeps popping through the carb.

I pulled the old plugs and they were black but otherwise looked OK so I cleaned and regapped them. Still popped. I thought it was the carb, it was dirty and leaking pretty bad. I got a kit, cleaned the carb and installed new parts and gaskets. Carb stopped leaking but still pops. Swapped in a coil I had, still the same. Bought new plugs, points, condenser, rotor and cap. Made sure the timing was on the mark and the points properly gapped, same. Then it wouldn't start at all, would spin over OK but sounded like no spark. Pulled the distributor cap off, ignition on and was getting spark at the points. Put it all back together brought over my daily driver and jump started the truck with 12 volt. Truck started and I took it around the block, popping all the way. So I thought maybe the plug wires were bad, they have to be at least ten years old, maybe older. I got a new set of wire today, install and same thing. Like I said, at idle it runs good and revs up pretty good with one or two slight pops but once under load fires off like a machine gun and about half power. Any ideas? One person suggested a stuck lifter. Could be, this is a pretty worn out engine, low compression and smokes a bit.

 

Could it be caused by back pressure from partially plugged exhaust pipe. Not sure if where you park it over the winter could mice possibly build a nest in there..just a thought..

 

How much vacuum does it pull? Any needle bounce when it pops? If it is backfiring through the carb, I would suspect a sticking intake valve. Change the oil and take it for a long drive.

 

I store it in my attached garage. As far as I know there are no mice out there but it could be a possibility.


It holds about 17 inches(?) and the need does bounce when it pops. How about some Marvel Mystery Oil? I don't really change oil much, it burns and leaks enough I just keep topping it off with fresh oil.

 

Sounds like it's short on fuel " too lean " . I would try it with your choke on just a touch .

 

When I do start it with the 12 volt jump I have to pull the choke out. I adjusted the float according to the in instructions that came with the carb kit. It also had a new accelerator pump. Everything seemed to be OK in the carb, nothing was sticking. Also, this problem was developing before I rebuilt the carb. Nothing I've done so far has changed the original problem. I'm thinking it's something internal to the engine. Oh yeah, at the end of driving season it was acting up. At the time I was having pinched nerve problems in my arm so I just parked it. So this is a problem that started last year.

 

 

Used to have problems with 305 Chebbys wearing out cam lobes. Exhaust valves wouldn't open much and as load increases exhaust couldn't get out, then when intake valve opens it goes back up intake and causes popping thru carb. Also had a 63 Chevy 6 cyl do it cuz of badly worn exhaust lobe on cam. Once you hear it you know the sound, used to be pretty common. I assume you have a flat head? Can you take off the air cleaner and see if it is popping thru the carb?

 

Just bought one of those from NAPA because of shorting at the distributor

 

I replaced that wire some years back after I drove my drove my truck someplace and wouldn’t start, turned out the wire broke. I had to trailer the truck home. It’s been a while, I’ll have to check it. It would be a cheap easy fix, what are the chances of that?

 

I would put it in the oil, as recommended on the bottle. Might clean up some sticking lifters , and/or stuck rings.
In the gas, it cleans buildup off the valves which may be preventing the valves from seating correctly (although Seafoam cleans the system faster).

 

Most of my repairs are cheap and easy after I have spent a lot of time and money on the wrong things

 

Yeah, me too. Fortunately everything I've done so far were probably needed anyway, especially the carb rebuild. In the 40+ years I've had the truck I've had the carb rebuilt four times, including now. The first I did 40 years ago, then had a "pro" do another about 20 years ago and it was a mess so I rebuilt myself again, which turned out better than the pro, and then now. So I guess they need to be rebuilt every 10 years or so. I've gotten used to modern vehicles that only usually need minor maintenance, these old truck are higher maintenance.

 

Another thing I have noticed is parts availability for these old trucks is getting really bad. No surprise really but still disheartening. I had to go to 4-5 places to get parts the last couple of weeks. I bought the carb from Rock Auto along with a new float. They sent me the wrong float so now I have to send it back on my dime even though they were in error, not happy about that. They sent me a wrong part a few years ago and I was able to told to a live person and have them pay for the return, now it's all internet, no live people to discuss a problem. This is why I prefer local, face to face transactions.

 

I had the same problem with Rockauto. After much research, I finally got through to a live person who told me their “terms and conditions” as stated on the website were outdated and no longer applied. They then hung up on me. That’s why I’ve given up on them. I’ve bought a lot of stuff from them over the years , but no more.