2001 Maxum 2900 SCR 7.4L STOPPED PLANING OUT!

[dave4boats]

Tank was drained and disposed
of. High test was because boat doesn't get used very much.

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[NautiGal]

Originally Posted by cdhunter

I am no expert, but it could be a fuel issue. Has anyone checked the fuel pressure at the fuel rail?

I'll ask mechanic if he's done that....my friend's husband suggested same thing.

[NautiGal]

Originally Posted by mmwjr

A bad sensor should show up in a fault code. I'm thinking a fuel related issue.

Guess that rules out a bad sensor then - good to know!
Consensus seems to be fuel issue so far....

[NautiGal]

Wanted to thank you all for your responses - you guys rock!! Will provide an update as things progress...

[rick911]

So did you get your problem fix? I have a 2001 2700scr that's doing pretty much the same as yours. Getting 4200 rpm out of it but it's so hard to get her on plane, just two ppl in the boat and full gas half water or more and she takes forever to plane. Is there's much current and wind/waves sometimes she didn't plane at all.
Same as yours it has a single 7.4, bravo three, 500 hrs. Getting fed up with this so much that I'm planning on getting rid of it but at the same time I know I should be fixed le and the boat should have enough power to get up and go

[mmwjr]

Originally Posted by rick911

So did you get your problem fix? I have a 2001 2700scr that's doing pretty much the same as yours. Getting 4200 rpm out of it but it's so hard to get her on plane, just two ppl in the boat and full gas half water or more and she takes forever to plane. Is there's much current and wind/waves sometimes she didn't plane at all.
Same as yours it has a single 7.4, bravo three, 500 hrs. Getting fed up with this so much that I'm planning on getting rid of it but at the same time I know I should be fixed le and the boat should have enough power to get up and go

Is this a new problem? When did it last run good? Perform a compression test on the engine.

[Phillbo]

Rick, call the guys at Hill Marine. They have a 4 blade prop set up for the Bravo III that makes a HUGE difference in the performance.

I have a buddy with a 2800 and the 7.4L. He would have to go down into the cabin and lay on the forward V berth while his wife drove the boat out of the hole. He would also have to run at a very high RPM to keep it on plane. The 4 blade props fixed both these conditions.

Stainless Steel Propellers, Boat Props, Marine Accessories | Hill Marine

[rick911]

Originally Posted by mmwjr

Is this a new problem? When did it last run good? Perform a compression test on the engine.

Started noticing it really last year, we moved the boat where there is more current and bigger waves and that's when it started getting really noticeable. I'll check compression a soon as I get back home next week

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[rick911]

Originally Posted by Phillbo

Rick, call the guys at Hill Marine. They have a 4 blade prop set up for the Bravo III that makes a HUGE difference in the performance.

I have a buddy with a 2800 and the 7.4L. He would have to go down into the cabin and lay on the forward V berth while his wife drove the boat out of the hole. He would also have to run at a very high RPM to keep it on plane. The 4 blade props fixed both these conditions.

Stainless Steel Propellers, Boat Props, Marine Accessories | Hill Marine

I actually ordered a pair of four by 4 from them but my original pros were 20p and he makes 20p or 18... Got 18p but now I received to hight at cruising spores. I need to call him to see if I can't swap em out for something that would work better

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[Phillbo]

I'm quite certain they will work with you to get the right pitch.

[NautiGal]

Hi guys! I am beyond thrilled to report that the problem is fixed and didn’t cost me a dime!!! =)

Mechanic decided to install a temporary “lift pump” between fuel tank and high pressure fuel pump. Said if she still wouldn’t plane out that would indicate bad fuel pump starving engine of fuel. While installing lift pump, he stumbled upon a loose clamp on a hose & replaced it...then said rather sheepishly that he was gonna feel like a complete idiot if it was just that d*mn clamp causing the problem all along! (lol) Ran her with lift pump & she planed right out so I’m figuring fuel pump is bad. Then we removed lift pump and ran her again to see what would happen. I was fully prepared for her not to plane but guess what?!? She planed out like a champ!!! So yea, it was just a loose hose clamp causing the problem all along!

Oh yea, regarding the small leak in risers that I mentioned earlier in thread…I was mistaken, mechanic said he checked risers during sea trial to make sure there was NOT a leak and there wasn’t so I just misunderstood him.

Thank you guys for all the feedback - much appreciated!!!

NautiGal (Dana)

[mmwjr]

That's great. Loose clamp allowed it to suck air.

Now get out there and enjoy the rest of the season.

[rick911]

What wot rpm are you getting now?

[Trooper2928]

Has your problem ever been resolved. I'm having the same issue after rebuilding the carb, a complete tune up, compression check, changed the fuel water separator filter. Think it has something to do with the bad fuel, or something with the tank. ie; screen or filter. Anything??????

[Phillbo]

Trooper.... Read post #31

[mmwjr]

Originally Posted by Trooper2928

Has your problem ever been resolved. I'm having the same issue after rebuilding the carb, a complete tune up, compression check, changed the fuel water separator filter. Think it has something to do with the bad fuel, or something with the tank. ie; screen or filter. Anything??????

Welcome aboard

You should start your own thread as you have a different setup, the OP has a MPI engine while you have a carb. Since it happened after the carb rebuild I would look there as something may not be set right.

[NautiGal]

I got lucky and we discovered a loose hose clamp....tightened it down & good to go now! However if too much weight in boat or full tank gas AND water she still doesn't plane very quickly. I've learned not to keep water holding tank full & that seems to do the trick.

[NautiGal]

4400 is WOT RPM now

[mmwjr]

Originally Posted by NautiGal

4400 is WOT RPM now

That’s the idle WOT. Enjoy