Low WOT, water logged floatation ?

[sundaypaper]

Hopefully I've picked the correct forum,

I have an on going issue with WOT stuck at 4200 RPM. Its a 3.0LX mercruiser on a 97 17ft starcraft bow rider. This started a few years back, but recently I had a head gasket replaced, carb rebuilt, tune-up, and she runs like a top but the WOT issue still exists. I replaced my prop last week with a new 14.5 x 19 (same as the original), and got 100 RPM back. I think I'm down to 2 items, fuel pump or water logged. What bothers me about water logged is this, I can be alone with not much fuel and it goes 4300 rpm and 37 mph. With almost a full load 5/6 people (900) lbs, it goes 4300 RPM and 35 mph. I'm thinking that since it runs so well, starting, idling, midrange, no surging that its not the fuel pump either but maybe I'm wrong about all this stuff. Any comments would be welcomed.

new: 4800 rpm, 41 mph, 14.4x19
today 4300 rpm, 37mph, 14.5x19
ratio I think is 1.98.

just having fun WayTooMuchFun anyways

 

[Alumarine]

Re: Low WOT, water logged floatation ?

Welcome.

You could weight it on the trailer and then weight the trailer to determine your weight.

You could drill a few 2 inch holes in the floor and check things out.
(don't drill through the fibreglass).

 

[pinecrestwoods]

Re: Low WOT, water logged floatation ?

You could drill a few 2 inch holes in the floor and check things out.
(don't drill through the fibreglass).

Actually, if you drill through the hull, you'll know if you're full of water. (JK.... don't do it..... I'm just being a PITA).

 

[sundaypaper]

Re: Low WOT, water logged floatation ?

I would consider weighing my boat but unsure where I could go to have it done ?

 

[mkast]

Re: Low WOT, water logged floatation ?

Any truck scale on the interstate or recycling center.

 

[NoKlu]

Re: Low WOT, water logged floatation ?

Most big truck stops have scales you can use.

 

[dgopetactical]

Re: Low WOT, water logged floatation ?

I had similar issues. put a inline fuel pressure gauge between the carb and the fuel pump..........I was only getting 3 psi when I should have 5 1/2 +psi.... put a new fuel pump on and I got my 400 rpm back.

If you did a tune -up a few years back I would start with that right now that could be all it is.
Denny