[622268]

I have an 88 mercury 50 I just had rebuilt. It starts well, idles well, pumps water etc. The only thing it doesn't do is push the boat if the rpms go over 2500. At lower rpm the boat moves forward slowly, at higher throttle, the engive revs up but there is no power to move the boat. I've looked at the prop, it looks good - no wear on the splines - it's only year old. I need some other ideas before I have to have them take it apart again!!

 

[mk5381]

Prop

sounds like the prop is spinning out. It could look good but still need to be re-hubbed. A quick check would be to take off the prop and put on a spare just to see if it pushes the boat.

Fatal Attraction

 

[seaslug44]

What size boat/how many passengers?

 

[sharphook]

Is it possible that the bottom of the boat is full of barnicles? They can make a boat feel as if it has a parachute on it.I have a 13.5 foot boston whaler i always had that problem...good luck

 

[622268]

re: your replies

thanks for the replies so far.
I will try the suggestion about using a different prop.
Boat is 17' cc with clean bottom.
Any other ideas out there?

 

[B.Attitude]

Sounds like you spun a hub,change the prop or have it re-hubbed.

 

[615099]

Definitely first try a new prop before you bring it in. This has to be the problem, Good Luck

option 1

 

[seaslug44]

Did you ever have this engine on this boat before, or is this your first experience with it?

 

[614035]

Mercury Engine

Franki,

I had a similar problem with my engine. As others have stated check the prop first. If you have an internal tank and a fuel water separator check that also. That was my problem. I had water in my tank. If that is the case you would have to drain the fuel and perhaps even have your carbs cleaned. My engine was a 90HP Mercury. Good Luck

 

[622268]

SPUN HUB!!

THANKS TO ALL POSTERS!

It was indeed a spun hub. Tried my spare and everything is fine. I could not make the bad prop spin by hand though. Hi-torque necessary!