Mariner 90hp 3cyl outboard help fule system

[Shawn Hall]

We just bought a pontoon boat with a 90hp Mariner 3 cyl. The engine starts up fine. I prime the engine with the priming bulb and it will run fine for about 45 seconds or so then it bogs down and looses rpms. If I pump the bulb again, the engine comes back up to the correct rpms. As long as I keep priming the engine as it runs, its fine. Any suggestions? I want to replace the guts of the fuel pump and replace the bulb. Will that do the trick?

We just replaced the plugs and checked all the coils and they are fine.

 

[guyjg]

You're on the right track. Verify the fuel tank vent is working by opening the fuel tank fill cap and running the engine. If the engine runs fine then the vent is blocked. The other thing to check is the fuel hose connections...there could be an air leak causing the fuel pump to suck air.