Clogged Carb? This is How You Fix It

Surely by now you’ve encountered an ethanol problem or two. Maybe your lawnmower has become finicky, your chainsaw never seems to run right or – horrors – your outboard’s carburator seems to continually become gummed up and fouled. We briefly mentioned in Duck Boat Blues and Outboard Motor Maintenance how to avoid this problem. Preventative maintenance boils down to adding a fuel stabilizer like Biobor or Star Tron, and draining the carb whenever you’ll let the boat sit for more than a couple of weeks. But we didn’t discuss what to do if your carb is already gummy – yet.

You have two basic options, and easy one and a more involved one. As you might expect, the easy option usually doesn’t work but it’s worth giving it a shot because it’s, well, easy. Essentially, you’re just going to clean the carb by shooting a bunch of Gum-Out carb cleaner into the breather. More than half of the time it won’t work, but now and again you’ll get lucky and your problem will be solved.

Here’s what a carb looks like on the inside, after you go through a full-tilt cleaning. If you can see any gum or goop in there, your outboard is not going to run right.

More likely, the problem won’t go away with such ease. In this case, you’re going to have to remove the carburator from the engine. Then, you’ll have to partially disassemble it and remove all plastic parts, like the float. In most cases, this is a pretty simple proceedure. Then submerge the carb in a bucket of solvent/cleaner, like Chem-Dip, and let it percolate in there for a good six or eight hours. The chemicals in Chem-Dip and similar products are pretty rough  - that’s why you had to remove the plastic parts, because them chemicals in this stuff will melt them away – and they should completely remove the offending gunk. After the dip is done, all you’ll need to do it reassenble the carb, put it back on the engine, andyou’ll be back in business. And don’t forget – an ounce of prevention is worth a gallon of chemical cleaner.