Propeller choice for Pearson 26 and 9.8 Tohatsu

[1972p26]

Hi, I am new to this list and 2 years into owning a sailboat. I just replaced the 1972 Chrysler 2 stroke 9.9 with a new Tohatsu 9.8 4 stroke long shaft. I believe it came with a 8 pitch three blade prop. There is a lot of vibration and resonance at most throttle settings. Since the engine is new I have not gone to wot, but at 1/2 throttle the engine sounds really labored. I seem to reach hull speed at about 1/4 throttle.

The factory rep recommended the 4 blade high thrust 5 pitch saying that I was lugging the engine with the 8 pitch. I'm nervous about buying the 5 pitch, I don't want to be running at full throttle and high rpm to reach hull speed.

I'm hoping someone can offer me some advice and perhaps their experience with a similar boat and engine?

Thank You!

 

[Joe]

Take the advice of the factory rep. Your existing prop is designed for small boats that can plane. Sailboats are heavier and have displacement restrictions on speed. Running you motor at its designed target RPM will insure optimal performance and a longer life.

 

[1972p26]

Take the advice of the factory rep. Your existing prop is designed for small boats that can plane. Sailboats are heavier and have displacement restrictions on speed. Running you motor at its designed target RPM will insure optimal performance and a longer life.

Thanks Joe, I will most likely do that. I am still curious what other folks with similar boats are using for props on similar ob's, and what you are finding for throttle settings and rpm at near hull speed motoring. Since winds are not always reliable here on the lake, there are times where a lengthy motor home is required. Looking to be fuel efficient and least strain on the engine.

Thanks

Warren

 

[sailingseadragon]

For what it is worth - Years ago when we had our '74 P26, we purchased a Honda 9.9 four stroke long shaft to replace an older outboard that came with the boat. The Honda dealer also recommended replacing the 3 blade with 4 blade "high thrust" prop... We did and we were very happy with the results.....

Garner

 

[1972p26]

Hi Garner, Thanks for posting! Do you remember what the pitch was on the 3 blade, and on the high thrust? Throttle setting difference between the different props for the same speed? Did the high thrust give you less vibration?

Sorry for all the questions, but I want to be as sure as I can that the High thrust prop will help with the vibration issue. I'd love to chat with you about your experience with the p26 as well as the 367.

Warren

 

[Roadking Larry]

I had the 9.8 Tohatsu long shaft on my Macgregor 26S. It had the 4 blade high thrust prop. I nver had any issues with prop walk with it and it would push the light Macgregor to hull speed at not more than 1/4 throttle.
The Tohatsu was absolutely stone cold reliable.

 

[Chief RA]

I have a 2013 Tohatsu 9.8hp,electric start, 25" shaft, 4 blade on my C250. It sips gas, quiet, low RPM for hull speed. 4 blade came on it and don't know the pitch . Great motor!
Chief

 

[1972p26]

Thanks everyone! I'm ordering the 7 pitch four blade, hopefully it will fix the vibration!

Warren