Boat won't go over 4,000 RPM's

[Maclin]

Re: Boat won't go over 4,000 RPM's

Looks like I was working on mine while you posted!

You are on the right track to see if that is the problem or not....it is kind if fun too!

 

[Ed R]

Re: Boat won't go over 4,000 RPM's

Hey, Go back to the basics, compression, fuel and spark at the right time. Your 5.7 should turn between 4200 to 4700 RPM.
Outdrive ratio should 1.50 to .1 turining anywhere from a 17 inch pitch to a 19 inch prop.
Need to determine whether you are starving for fuel or if running on all 8 cylinders. I have always ran boat at high RPM, pulling off spark plug wires from distributor cap to make sure all cylinders are firing.

Good Luck!
ER

 

[MikDee]

Re: Boat won't go over 4,000 RPM's

Hey Ed, Just so you know, this is an inboard tournament style ski boat. By the way, as sarantis mentioned, is the hull bottom clean?

 

[AaronWhitt82]

Re: Boat won't go over 4,000 RPM's

Hey, Go back to the basics, compression, fuel and spark at the right time. Your 5.7 should turn between 4200 to 4700 RPM.
Outdrive ratio should 1.50 to .1 turining anywhere from a 17 inch pitch to a 19 inch prop.
Need to determine whether you are starving for fuel or if running on all 8 cylinders. I have always ran boat at high RPM, pulling off spark plug wires from distributor cap to make sure all cylinders are firing.

Good Luck!
ER

It's getting plenty of fuel, great spark, all cylinders firing.
I still need to get the timing checked, and should check compression in all cylinders as well, but I still think it is a carb problem.
By the way the stock prop size for the boat is 13X13 which is still on it in perfect condition. The ones you mentioned are way too big of a pitch and would be for an outboard.
The transmission ratio is also 1:1 and is a Hurth tranny.
Bottom of the boat clear? Haha you bet it is with a nice slick coat of wax.....

I did contact Indmar and they confirmed that the carb is a 600 CFM

Sooo time for some tuning this weekend.

Thanks

 

[viettim]

Re: Boat won't go over 4,000 RPM's

i seem to have a similar problem with my mercury 4.3l v-6. seems that i may want to try the idea with someone driving and play with manually openning the secondaries. also, i just bought it and know that it sat last seans with only a couple of rides. it's a 2003 with only 130 hours. i know the bottom part of the skeg is broken off (knew that when i bought it)...figured i would get that repaired, but just read a littl about skeg guard...perhaps that's a good way to go?

 

[Don S]

Re: Boat won't go over 4,000 RPM's

Start a new thread with your question viettim, or in no time your question will be lost. As many readers only read the original question and answer it. Besides, this thread is about Aarons problem, let's keep it at that.

 

[jantore]

did you fix it?