Mercarb Rebuild

Dis Assembly

1st remove the choke to fast idle cam rod and the pump rod.
Remove the fast idle cam screw.
Mercarb marine carburetor rebuild
  • Remove the choke thermostat (3 screws).
  • Remove the lever attached to the choke shaft. Be careful, this screw is easily broken.
  • The housing is attached to the main body with 2 screws, which you need to remove.
  • Remove the gasket.
Mercarb marine choke removed.
  • Remove the 8 screw from the top of the carburetor. Note that one screw is a bit longer than the others.
  • Remove the Venturi (3 screws). The middle screw is different from the 2 outside screws. It should have a washer and a fiber gasket.
  • Remove the power jet, using a full bladed screwdriver so you don’t chip the jet.
  • Remove the main jets, again using a full bladed screwdriver.
  • Remove the float by pulling out the float pin. Test your float by heating up a pan of water and immersing the float. Any bubbles indicate a leak.
  • Loosen the philips screw holding the accelerator pump to the pump lever and pull the lever out. Make a note how the pump attaches.
  • Be sure to remove all of the gasket material.
  • Use an awl to scrape any staked over metal from around the power piston. Push down with your thump, then let it go so that the piston pin snaps back. Keep doing this until the piston pops out.
Mercarb Marine Rebuild

Remove the fuel inlet fitting & filter. Notice how this will go back together, spring, filter with closed end toward the carburetor and then the gasket, or washer.

Soak all parts in a gallon of carburetor cleaner following manufactures directions. Not following directions may discolor, or damage your carburetor.

Polish the pump well with crocus cloth to make it smooth. Ethanol gas has little lubrication which can damage a good pump. The pumps needs to glide smoothly.

Mercarb Marine Throttle Body

Assembly

Mercarb Throttle Body

Updated on 04/06/2021

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