Low power and cannot get on plane - Maxum Boat Owners Club

Willa1972 · 08-23-2010, 01:38 AM

Hello I am having a problem suddenly getting on plane, Just did a tune up, hoping this would help. Any Ideas where to start for troubleshooting? RPMs won't go higher than 4200-4300 and wake shoots up in the middle. Used to run about 23 knots+ now only around 13 knots and not any gain soon before the throttle is all the way down. Any advice would be awesome as we are only a year into boating!

Tommyfmu · 08-23-2010, 03:33 AM

Would have to know more about the boat like size, 1 eng or 2, inboard, i/o etc, and most important are you propped to mfr spec? If you are pushing water at WOT unable to get on plane, first thing to try is to drop trim tabs all the way. If you get on plane you can raise them a bit to get optimal cruise without cutting the bow through the water.

On my current boat I leave tabs down all of the time except when adjusting for list. Without tabs down, I'd push water and never get on plane, but that's due to having inboards. With outdrives and engine trim you can adjust using that instead of going to tabs first.

tackleshep · 08-23-2010, 03:52 PM

If the wake is shooting up in the middle it really sounds like the drives are not trimming down all the way. Might inspect that out of water or in water where you can feel if they are going up and down correctly. When I got my boat I had a solenoid go out and drive wouldn't drop right.

Willa1972 · 09-28-2010, 02:50 AM

Thanks for responding, Its a 2000 maxum 2800 scr, i/o engine, 7.4 ltr mercruiser MPI It ran fine all summer then all the sudden!! No plane no more!! lol Someone said it could be a fuel filter

seapuppy · 09-28-2010, 03:46 AM

well..with an mpi engine and your hitting 4200 rpm...your right close to the lower limit to the rpm range...now if your hitting that rpm and no speed...depending on what drive you have...you could have a spun hub.....but since your shooting water up into the air...I'd say your drive isn't down far enough..thus your speed is reduced...your rpm is up and your getting that gyser......

so the other question to ask is what drive do you have...???

oh yeah...welcome to the zoo.
SP

shrew · 09-29-2010, 07:41 PM

Quote:

Originally Posted by seapuppy

well..with an mpi engine and your hitting 4200 rpm...your right close to the lower limit to the rpm range...now if your hitting that rpm and no speed...depending on what drive you have...you could have a spun hub.....but since your shooting water up into the air...I'd say your drive isn't down far enough..thus your speed is reduced...your rpm is up and your getting that gyser......

SP

Ditto on either spun hub or drive out too far. With the rooster tail, i would also lean towards the drive being out too far. I would think that would be cavitating like crazy and the sound would be pretty unmistakable.

Willa1972 · 10-02-2010, 05:48 AM

The outdrive is a Bravo 3, Guess I will just find out what is wrong with it when I pull it out for the winter.....