1987 Force 85 HP losing power at full throttle

[pmcd1222]

I'm a new boat owner and learning the very valuable lesson right off the start. Boats are work....

The trouble I'm having is that when I put the motor into full throttle, it acts like it's lacking fuel.

I just replaced all inline valves on the carbs.
I've replaced the fuel pump diaphram.
I've checked all fuel lines. They all seem to be relatively new.

I also notice at the same time the motor boggs down a bit, my fuel gauge also goes down simultaneously.

The boat starts up without issue and runs great all the way until I push the throttle all the way down.

Can anyone recommend the next step in troubleshooting this issue?

Thanks;

Pat

 

[Jiggz]

Install a clear fuel filter (even a cheap Fram G2 will suffice) between the fuel pump outlet and the carbs' inlet. Orient it closer to the fuel pump so the inlet side is higher than the outlet side. This fuel filter is more for troubleshooting than filtering. Ran the motor and watch if the clear fuel filter stays at least 1/2 full. If it does, then the problem is with the carburetion and not fuel delivery. If it doesn't then the problem is with the fuel delivery, faulty fuel pump, leaky fuel hoses or primer bulb, or clogged suction tube, etc.

 

[jerryjerry05]

(inline valves on the carbs) ????? What's that?

​If you rebuilt the carbs? Then the floats might be set wrong?
Or possibly the vent line from the tank is clogged.
Hoses and the squeezie can look good but Ethanol melts the inside of the hose and it can collapse the inside.
The inline connectors, over time the rubber seals can rot and leak allowing it to suck air.

Oh yea Welcome!

 

[pmcd1222]

The inline valves are what I was describing the two fuel lines between the three carbs. Sorry I've certainly learned a lot over the past couple weeks. My terminology is improving. However, I'm not sure what you're referring to when you say inline connectors? I have noticed that behind the carbs, after I remove the front housing for the reeds that the gaskets right infront of the reeds are very old and decaying. But I would think as snug as the housing sits, the gaskets there shouldn't be an issue. Maybe I'm mistaken.

 

[jerryjerry05]

The inline connectors are any quick connects or inline plugins.
.​Anything in the fuel line.
The connectors have rubber seals that deteriorate over time.
Post a pic of the "inline valves" ???

Bad gaskets: that certainly could be a problem.
Sucking air is a huge problem.
Replace the gaskets and if your worried use a sealer on them.

The gasket behind the carb can be a problem too.

You should combine these posts as they are for the same problem.

 

[pmcd1222]

After several more hours, I discovered that the air jets and fuel jets inside 2 out of 3 of the carburetors were set backwards. The guy I paid to rebuild the carbs was pretty much blind and missed this. He fairly gave me a good portion of my $ back. So I will give him credit for that, just not the work he did. Boat runs like a dream.

Thank you all for your feedback. It certainly kept me looking at the right things.

Pat