Poor Performance.

[bracboy]

I have a 1997 60 hp on a 16 ft deep V fiber-fishing boat. I recently installed a 14 pitch prop which online prop selector suggest should give best results, But the plane time is bad and i only top out at 4400 RPM? Not sure of speed because my gauge is broke. Any ideas?

 

[Greg New Zealand]

Re: Poor Performance.

bracboy<br /><br />Sounds like too much pitch. Your prop is biting more than it can chew! A lot depends on your laden hull weight and shape verses motor power. But you are certainly way off your WOT range. Can you go back to wherever you purchased it and try another with less pitch? <br />Someone like Lubedude on this forum will come up with a pitch suggestion - I don't want to guess.<br /><br />Greg

 

[LubeDude]

Re: Poor Performance.

Well, because my name was mentioned, I will jump in. What was the original prop pitch? Prop selector charts only get you in the front gate, not necesarily into the ball park. If the engine is running at its full potential, (Im not sure it is), you would have to go to an 10P or less to get into the ball park. Im sure your optimum RPM must be in the 5-5,500 RPM range. Are you sure you havnt dropped a cylinder?

 

[rickdb1boat]

Re: Poor Performance.

A 60 HP on a 16'er will have no problem reaching at least 5000 RPM's, if it's running right with a 14" pitch prop. There could be other factors, such as a waterlogged heavy hull or the motor may be mounted too low. You're looking for 5500 RPM's and you are not going to get it with a lower pitched prop. Something is amiss... Is there any other history you can provide us about your boat and motor? In particular, the weight of the boat normally loaded and where is the cavitation plate in relation to the bottom of the hull? What brand of prop?