WOT - on my 15hp

[geedubcpa]

Is it ok to run a 15hp 2 cycle in WOT most of the time - It is for my pontoon boat and basically its the only way to maintain speed.

I guess i wasn't sure if running this way would drastically reduce the motor life.

 

[psteurer]

Re: WOT - on my 15hp

I run my 20hp Johnson WOT all the time. The key is to make sure you have the right propeller. I believe my manual says WOT is between 4500-5500 rpm's. That should be similar for your motor. I am running a 10x13 inch prop. You might be able to step down to a 9 inch pitched prop (i.e., 10x9) if you are pushing a heavy load. You really need a tachometer to measure the rpm's accurately. Running WOT with the wrong size prop will cause premature problems for your motor.

P.S. For fuel economy, you might want to nudge back on the throttle just a bit. That saves a lot

 

[Chinewalker]

Re: WOT - on my 15hp

Your 15 should be peaking in the 6000 RPM range. If you aren't propped to do that then running it wide open will kill the motor by lugging it down. Kinda like driving up hill in fifth gear while towing a trailer...

 

[crxess]

Re: WOT - on my 15hp

As above. You never want to over rev, but the motor must be able to reach correct WOT rpm's to function properly.

If needed, a lower pitch prop will make a world of difference.

Just went through this with my 6hp. Dropped from 8x8p tp 8.25x5p and tripled my speed while fixing WOT issue.

Oh, and 3x speed = 8 mph up from 2.5

 

[tx1961whaler]

Re: WOT - on my 15hp

As above. You never want to over rev, but the motor must be able to reach correct WOT rpm's to function properly.

If needed, a lower pitch prop will make a world of difference.

Just went through this with my 6hp. Dropped from 8x8p tp 8.25x5p and tripled my speed while fixing WOT issue.

Oh, and 3x speed = 8 mph up from 2.5

Not to hijack, but where did you get the prop for the 6 HP?

 

[crxess]

Re: WOT - on my 15hp

Not to hijack, but where did you get the prop for the 6 HP?

Unfortunately I think I just bought the last 2 in existence. Found them on ebay from a dealer in Cali. After testing one and (unfortunately) destroying one on some rocks, I grabbed what I could find.

Part is 0386587