'01 25 hp Johnson acts like spun prop. hub...

[hcrumbie]

I've a 2001 25 Johnson on a 17' Lowe aluminum bass boat that acts like the hub is spun. Here are the symptoms and what I've done to date. It engages fwd or rev ok. It'll run at any throttle position for a while without any problems. After a few min's at hi or full throttle the engine revs, and the prop looses power and the boat steers left. Back off of the throttle and it'll run ok until the power is up again. I don't usually run at WOT for long, tending to stay at about 75-80% when running at high speed. Based on reading posts in this forum I've purchased a replacement prop and had the OEM prop reworked. No change in symptoms using either prop. What else might cause this to occur?<br />Thanks, HC

 

[ShafferNY]

Re: '01 25 hp Johnson acts like spun prop. hub...

Maybe the wrong pitch? I really have no idea thats just a guess.

 

[hcrumbie]

Re: '01 25 hp Johnson acts like spun prop. hub...

The prop is a 10x13 as supplied by the dealer. They set it up to run a bit below the OMC spec for WOT RPM. Question ... what does the 13 in 10X13 represent? 10 is the diamater and 13 is the pitch, but how many whats does this 13 indicate? Why not back to the dealer? I live in a small town and it's about an hour and a half up there, and the boat/motor warranty has expired. Thank goodness it's only a 10 min. drive to the boat ramp!!

 

[Rex Birt]

Re: '01 25 hp Johnson acts like spun prop. hub...

Rivrrat I believe what you are looking for is (degree) 10 inches and 13 degrees. You might need more or less degree to produce the speed you want. I think that weight has a factor in this too. It sound like you are not getting enough water through your prop and there for the motor revs high. If you were happy before you change your prop you should go to the same one. Good luck<br /><br /> catfish156123

 

[steelespike]

Re: '01 25 hp Johnson acts like spun prop. hub...

Could be a cavitation problem.Your motor may need to be lower or trimmed in a little bit.(prop closer to the boat.

 

[hcrumbie]

Re: '01 25 hp Johnson acts like spun prop. hub...

Thanks catfish156123 and steelspike. I haven't changed from the pitch or size supplied by the dealer. But I do carry a spare now! <br />I chase catfish on the Big Cypress Bayou here in Jefferson as much as possible. That involves hitting a stump or two no matter how<br />you may try to aviod them. I did make sure NOT to hit anything with either new prop by putting in at the lake and somehow<br />resisting the urge to fish, sticking to the task of testing the boat. <br /><br />I'll try moving the motor in one notch and see if that changes things. <br /><br />"When you work on an outboard<br />without a manual you have a fool for a mechanic"...not to mention a few leftover parts.