The Stovebolt Site Forums The Shop Area The Electrical Bay Help me with fouling!

Truck: 1953 Chevy, all stock except 12v conversion
Problem: I can only drive about 50 miles before my plugs are fouled up and then start misfiring.
What should I do?
I'm considering going to a modern pointless ignition, if so, is there one that looks stock?
thanks

Without being able to see the plugs in person I would probably say to ask for a hotter spark plug.

You might want to check the jet in the carburetor to make sure you don't have too big of a jet for the engine size.

What does the fouling look like? If it's black and sooty, that's an over-rich fuel system, and working on the ignition won't help. Black and oily is oil fouling, caused by bad rings, leaky valve guides, bad PCV valve, etc. Again, ignition tinkering isn't a fix. Eletronic ignition won't solve a fuel or oil fouling problem. If the spark is too weak to fire the plugs reliably, they'll fuel-foul, but there will be other problems almost immediately, very poor performance, missing on a pull, or under acceleration, and such. Check out the fuel system before you start changing ignition systems.
Jerry

Some more info on my problem:
I'm using AC Delco R45 spark plugs.
The fouling is mostly black sooty, not oily.
Stock carb, rebuilt about one year ago.
Have not had engine rebuilt in decades.

Thanks for all the help.
If I do have a fuel/mixture problem, I'm not really sure where to begin, so I'd appreciate any comments.

First, get the engine idling with the air cleaner off, and look down into the top of the carburetor with a bright flashlight. If fuel is dribbling out of the venturi area, about the middle of the carb body, it's flooding. Look for a hole in the float, or dirt between the needle valve and the seat area, where the fuel enters the carb. The float and the needle valve work just like the ballcock valve in a toilet, they're supposed to maintain a stable fuel level just below the point where the gas can overflow into the air stream. Most likely, you've got dirt in the fuel, and even a tiny piece of debris can cause the carb to flood. Get the carb clean, and install a good inline fuel filter to trap the crud before it reaches the carb. Worst-case scenario, pull the fuel tank and have it cleaned by a radiator shop, or replace the tank if it's really in bad shape!
Jerry

Thanks Lincoln. I'll perform that test and see what happens.
I have an inline fuel filter just before the carb, and there is little debris.
I've had the problem you described in the past, with the carb gumming up and the float sticking. But I rebuilt the carb not too long ago, so I don't think that is it.
As far as jets go, I don't have a clue which one is in there, or if it is right. Its just whatever came with the stock carb I guess. (The truck was my daily driver twenty years ago, it sat for ten years, and now I'm getting it back on the road. So the jet should be the original.)
The truck runs great with new plugs, just doesn't take too long for them to foul up.

One other possibility- - - -the carb has a "power valve" that richens the mixture on acceleration. If it sticks, you're running full-rich all the time. There will be a long brass rod in the top of the carb, that works against a spring-loaded valve in the carb body. Pull the top of the carb, and make sure the plunger is free to move. A squirt of spray carb cleaner and a little work will usually free up the plunger. A stuck power valve will really increase the fuel consumption, and foul plugs quickly, even if the carb isn't flooding.
Jerry