Thompson 190 BR with Mercruiser 4.3L - runs great for 10 min, then stalls under load

[ladchapman]

We bought a used entry level boat (1991 Thompson 190br) and it runs great for 10-15 min. Then we get a skier or tube set up and it dies out under load at 2000 rpm. Then it won't run for more than 10 seconds at idle for the rest of the day. Next day, same scenario. We changed both fuel filters and the cap and rotor. I've seen that others have had similar issues. My boat does not have a separator - i'm thinking of installing one but I'm really just hoping that somehow there's water in the fuel?

 

[alldodge]

We changed both fuel filters

The both filters is the one on the pump and the one inside the carb behind the fuel line?

Need to check your fuel pressure, should be between 4 to 7 psi
https://www.amazon.com/Actron-CP7803-Vacuum-Pressure-Tester/dp/B0006V2BS2

 

[kulle]

I'm having "similar" symptoms, curious to know what the outcome is.

 

[greno]

Sounds like a fuel restriction. First, put a fuel pressure gauge on and see if you have enough fuel pressure. If fuel pressure starts out good and then goes low you have a restriction upstream. If fuel pressure stays good then you have a carb issue.