Mercarb IdentificationFinding the carburetor number.
Purchase one of our famous Mercarb ethanol ready rebuild kits. At this time our carburetor kit fits all Mercarb carburetors, but if you need to know the carburetor number look near the fuel inlet fitting. You may have to scrape some of the black paint off to see the number. In this case the number looks like this: 1389-9564. Generally the 9564 is enough to identify the carburetor.
Mercarb RebuildTake plenty of photos as you take your Mercarb apart. You may need to refer to them when putting your carburetor back together.Watch our Mercarb rebuild videos.
Part 1 - Dis Assembly
Part 2 - Assembly
Take the carburetor apart, then inspect the parts for damage, or excessive corrosion. White residue at the bottom of the float bowl, which is probably dried up ethanol gas isn't such a big deal and should clean up nicely. Look for particles of black rubber. That would be the ethanol eating the inside of your fuel hose. Replace all fuel hoses when this happens.
Since marine engines tend to sit for long periods of time, the gas may have turned and varnished up the inside of the carburetor along with the gas tank. A strong smell of varnish will be present when this happens. If the carburetor is corroded in the bottom of the bowl, then the carburetor should be discarded. Any corrosion would indicate that one or more of the small passages have corrosion which you will most likely not be able to remove.
Soak in a carburetor cleaner dip purchased from your favorite parts store. Follow the directions on the can. For example one product suggests 20 minutes of soaking. Soaking too long will discolor your carburetor, so be sure to follow directions. Rinse in hot water, removing all traces of chemicals. Many chemicals react with ethanol gas. Blow out all passages. As you go along determine where the passages leads, then feel the air going through the passage to be sure it isn't clogged. Pay special attention to the small holes in the venturi.
They can easily get plugged.
Paint the outside of the carburetor black if needed.
Dirt is the biggest cause of carburetor problems, so be sure to replace all fuel filters. Many good carburetor rebuilds go bad because of dirt in the gas tank.