|Mercruiser Sterndrive Information|
Checking your Carburetor
You can look up your exact Carburetor or Carburetor Repair Kit HERE.
Click HERE for a list of Remanufactured Carburetors.
Engines need the three basics to run. Fuel, Spark and Air.
If you are having engine performance problems and you know you have good spark, you can suspect your fuel system.
Any backfiring may indicate a lean fuel condition such as a clogged carb or restricted fuel supply.
A carburetor can get "varnished" from sitting after a few months. This varnish coats the inside of the float bowl and cloggs the jet passages. It's pretty easy to tell if your carb is varnished. Remove the engine flame arrestor (engine off!) and give the carb a good sniff. If the carburetor smells like varnish it will have to be rebuilt.
Simply spraying carb cleaner into the carb will not fix a varnished carb. It must be completely disassembled, scrubbed clean and reassembled.
If you sniff your carb and you know it hasnt been sitting long enough to varnish, you might have dirt or water in the carb. You might also have a fuel supply problem. Water in the fuel is a very common problem. Remove the fuel filter(s) and dump them into a clean bucket. Look for evidence of water in the fuel. If you find water in the fuel and you suspect that it has gotten into the carb, the carburetor will have to be removed and rebuilt.
Checking the fuel supply is usually done before assuming that the carb needs to be rebuilt. Perform a complete visual inspection of the entire fuel system. Check the hoses, clamps, fittings, pump and pick-up tube. Most fuel tanks have an antisyphon valve installed into the tanks pick-up tube. Read more about checking your antisyphon valve.
Another common carburetor problem is a stuck choke. The choke should be closed when the engine is cold and open when the engine is fully warmed up. Make sure the choke mechanism is free and properly adjusted.
If your engine tends to hesitate when you accelerate, you might have a bad accelerator pump. The accelerator pump is just a rubber piston inside the carburetor that squirts fuel into into throats of the carb while accelerating. If the rubber piston gets worn out it will not supply enough fuel to allow the engine to speed up. Most carburetor repair kits include a new accelerator pump.
Boats can explode. Moving parts can rip your off your fingers. Hot exhaust can burn you to the bone and props can slice you up. One spark near a battery can cause an explosion. You can never be too careful. Remove the battery from the boat before working with fuel. Always disconnect the batteries negative terminal first. Clean up any spilt fuel and let ALL of the fumes dissipate before installing the battery and starting the motor. Pulleys and Belts can grab your clothes and hair. Don't wear loose clothing and keep your hair up under a hat. Always wear safety glasses. Be smart.
|©2004 Sterndrive-Information.Com Email About Us Home|| Mercruiser Help Shop Manuals Message Board Contact|