3 Blade Prop & a 1GM10

[William Church]

I have a 3 blade 12x9 prop on my 1980 h27 which is powered by a Yanmar 1GM10. My diesel machanic wants me to replace the prop with a 2 blade prop. He feels that a 3 blade prop should never be used on a 1 cylinder engine. The prop shop tells me that the machanic is all wet and the issue is prop pitch and not the number of blades on the prop. Any ides as to who is correct, can you use a 3 blade prop on a 1 cylinder engine?

 

[Pete]

props

I'm not a expert but they use three blades props on small outboard why not on inboards? I think the issue is wether or not the engine can handle the prop does it rev up to full rpm spec? If you are not overloading the engine I think it would be fine. Just my un-expert opinion ! Pete

 

[Gordon Torresen]

Pete's the expert.

Ignore the soggy mechanic and listen to Pete.

 

[Bob Haskell]

3 blade prop

I have a Hunter 30,1978 with a Yanmar 10 hp engine with a 13X13 3 blade prop. Yanmar says I should be able to achieve 3500 rpms at full throttle and underway and we can,however 2200 rpms sounds and feels a lot better.If your mechanic is not familiar with these thoughts perhaps you should educate he or she that is, of course, assuming I am correct.  Have a good one and Aloha from Bob and Lynda and the S/V BlackMist.

 

[Bob Haskell]

3 blade prop

I have a Hunter 30,1978 with a Yanmar 10 hp engine with a 13X13 3 blade prop. Yanmar says I should be able to achieve 3500 rpms at full throttle and underway and we can,however 2200 rpms sounds and feels a lot better.If your mechanic is not familiar with these thoughts perhaps you should educate he or she that is, of course, assuming I am correct.  Have a good one and Aloha from Bob and Lynda and the S/V BlackMist.