AmericanKiwi
Recruit
- Joined
- Jul 22, 2008
- Messages
- 3
I have some propeller questions, but first I need to give you some background?
I have a 23ft 2006 Nautic Star Deck Boat with an F225 Yamaha outboard. The manufacturer lists dry weight as 2700lbs. It came from the dealer with a 13-3/4 x 21 Aluminum propeller. I called Nautic Star recently to ask what size prop they would recommend for a switch to stainless and they recommended 15-1/4 x 19. I figured the best match for my Yamaha would be a Yamaha SWSII and I installed it this past weekend.
I immediately noticed a significant increase in the ?clunk? when shifting into gear however this was anticipated with the dramatic increase in weight of the new propeller. What I did not expect was the audible vibration/rattle I experienced once I shifted into gear and at minimum RPM?s. This rattle however disappeared as soon as I started to give it some gas and the prop performed fantastically throughout the rest of the rev range.
I called Yamaha USA service dept and was told that either my drive shaft was bent (which I do not believe is the case) or that it was ?prop chatter?. I was not offered an explanation, but it was suggested that this could be eliminated by contacting my dealer and having then increase my low idle revs. I called my dealer and he informed me about what I understand is commonly called ?prop rattle? that is sometimes a result of changing to a heavier stainless prop and changing the size and pitch. He did not recommend adjusting the min revs as he highlighted that this would exacerbate the ?clunk? when shifting into gear and he said his experience was that this rattle is more annoying than actually detrimental to my outboard. He suggested living with it or changing props.
My problem is that at $500 a prop it is an expensive proposition to change props in the hope that I find one that eliminates this rattle but still gives me the performance I am seeking.
Now my questions:
1. I want to eliminate the possibility of a bent shaft or a propeller that is not balanced. Surely if I had either of these issues then the rattle would become significantly worse as I increased revs?
2. I struggle it believe this ?rattle? would not be doing harm to my motor. My instincts tell me that any resonance is bad and potentially damaging?
If it is ?propeller rattle? as I am now referring to it as. Then any information, comments or suggestions you can give me on this subject would be appreciated.
I have a 23ft 2006 Nautic Star Deck Boat with an F225 Yamaha outboard. The manufacturer lists dry weight as 2700lbs. It came from the dealer with a 13-3/4 x 21 Aluminum propeller. I called Nautic Star recently to ask what size prop they would recommend for a switch to stainless and they recommended 15-1/4 x 19. I figured the best match for my Yamaha would be a Yamaha SWSII and I installed it this past weekend.
I immediately noticed a significant increase in the ?clunk? when shifting into gear however this was anticipated with the dramatic increase in weight of the new propeller. What I did not expect was the audible vibration/rattle I experienced once I shifted into gear and at minimum RPM?s. This rattle however disappeared as soon as I started to give it some gas and the prop performed fantastically throughout the rest of the rev range.
I called Yamaha USA service dept and was told that either my drive shaft was bent (which I do not believe is the case) or that it was ?prop chatter?. I was not offered an explanation, but it was suggested that this could be eliminated by contacting my dealer and having then increase my low idle revs. I called my dealer and he informed me about what I understand is commonly called ?prop rattle? that is sometimes a result of changing to a heavier stainless prop and changing the size and pitch. He did not recommend adjusting the min revs as he highlighted that this would exacerbate the ?clunk? when shifting into gear and he said his experience was that this rattle is more annoying than actually detrimental to my outboard. He suggested living with it or changing props.
My problem is that at $500 a prop it is an expensive proposition to change props in the hope that I find one that eliminates this rattle but still gives me the performance I am seeking.
Now my questions:
1. I want to eliminate the possibility of a bent shaft or a propeller that is not balanced. Surely if I had either of these issues then the rattle would become significantly worse as I increased revs?
2. I struggle it believe this ?rattle? would not be doing harm to my motor. My instincts tell me that any resonance is bad and potentially damaging?
If it is ?propeller rattle? as I am now referring to it as. Then any information, comments or suggestions you can give me on this subject would be appreciated.