Repowering 1990 sailfish with yamaha 200 four strokes

[Ronaldolney]

I am repowering my 25 sailfish with new Yamaha 200 fourstrokes from 200 HPDIs. My question is my props that were on the HPDIs were 14.25 x 19. The max RPMs I would get was around 5100. Was wondering if anybody has any recommendations on what prop they use with Yamaha 200 4srokes on a 25 sailfish.

 

[ScottyCee]

I'll bet you need to drop to a 17" or possibly lower. The 4 strokes really like rpm...

 

[Ronaldolney]

I'll bet you need to drop to a 17" or possibly lower. The 4 strokes really like rpm...

That is what I was thinking but wasn't a hundred percent sure. would you keep the 14.25 diameter or go up a little. Just hate to buy 2 props and they not be enough to get my rpms up.

 

[wrxhoon]

Assuming you are looking at the 4 cyl ( you can get V6 200 hp as well) they have 1.86 gears same as HPDI but they make power at higher rpm . WOT at 5100 the HPI's are about right but the F200 you need to be 5500 if you want to be at the mid range .
I would think 17" pitch, maybe even 16 .

 

[Ronaldolney]

Assuming you are looking at the 4 cyl ( you can get V6 200 hp as well) they have 1.86 gears same as HPDI but they make power at higher rpm . WOT at 5100 the HPI's are about right but the F200 you need to be 5500 if you want to be at the mid range .
I would think 17" pitch, maybe even 16 .

I bought the 4 cyl 4 strokes since they are about the same weight as the HPDIs. would you keep the 14.25 diameter with the 17 pitch. I do have room to go up on the diameter. Just do not know how much it would make a difference. Thanks for your input.

 

[trapper]

Yamaha does recommend the Reliance series for the F200i4. Mine is on a 208 and am running the Reliance 15p. I know it is not a Sailfish but thought I would throw in my 2 bits.

 

[wrxhoon]

I bought the 4 cyl 4 strokes since they are about the same weight as the HPDIs. would you keep the 14.25 diameter with the 17 pitch. I do have room to go up on the diameter. Just do not know how much it would make a difference. Thanks for your input.

Bigger diameter will give you more lift and better hole shot all else being equal. You have 2 props so I don't think you need more blade in the water. Bigger blades are better for heavier and slower craft, smaller diameter is better for faster craft. A 25' sailfish with 400 Hp should be a fairly quick boat. If I was you, I would stick with the lower diameter. The HPDI's should have more torque and make the max power at lower RPM than the 4 strokers. If you go with bigger diameter more than likely you will need less pitch .
Of course all the above will depend on how much load you have too.
Why not run the motors in with the 19's you have , when you have say 5 hours running run them at WOT and see what RPM you get, then you will know what pitch you need.
Every inch you move up or down will change the RPM by 150-200 RPM all else being the same ( load and diameter).
Good luck with it, actually it is not a bad problem to have, brand new engines, good reliable running for 10 years.

 

[Ronaldolney]

Yamaha does recommend the Reliance series for the F200i4. Mine is on a 208 and am running the Reliance 15p. I know it is not a Sailfish but thought I would throw in my 2 bits.

I appreciate any recommendations. I am thinking about buying some aluminum props to try before I order the stainless steel ones and just have them for a spare.

 

[Ronaldolney]

Bigger diameter will give you more lift and better hole shot all else being equal. You have 2 props so I don't think you need more blade in the water. Bigger blades are better for heavier and slower craft, smaller diameter is better for faster craft. A 25' sailfish with 400 Hp should be a fairly quick boat. If I was you, I would stick with the lower diameter. The HPDI's should have more torque and make the max power at lower RPM than the 4 strokers. If you go with bigger diameter more than likely you will need less pitch .
Of course all the above will depend on how much load you have too.
Why not run the motors in with the 19's you have , when you have say 5 hours running run them at WOT and see what RPM you get, then you will know what pitch you need.
Every inch you move up or down will change the RPM by 150-200 RPM all else being the same ( load and diameter).
Good luck with it, actually it is not a bad problem to have, brand new engines, good reliable running for 10 years.

Thanks for the feedback, I sold my old props with my HPDIs, I am getting motor mount powder coated and hope to get new motors put on in next couple of weeks. I am thinking about buying some aluminum 17s but not sure if I should go up with the diameter. I have room but just not sure if I need too.

 

[VeroWing]

I would guess 15x17, but you should both consult Grady White, Yamaha, and perhaps a prop specialist before making your choice. There are also prop selector tool guides online that consider vessel weight, etc to give you a "rule of thumb" guide to choosing correct prop, but I would go with the pros on it.

 

[Ronaldolney]

I would guess 15x17, but you should both consult Grady White, Yamaha, and perhaps a prop specialist before making your choice. There are also prop selector tool guides online that consider vessel weight, etc to give you a "rule of thumb" guide to choosing correct prop, but I would go with the pros on it.

Thanks, I will call Grady White and see what they say.