What a difference 3/4" makes

[Rayvon]

Ever since I bought my Grady 208 I knew something wasn't quite right performance wise. With a F225 Yamaha it should have run faster with a 17P prop and the revs wouldn't go up when I trimmed it out. I was WOT at 5300 RPM at 36 MPH. I tried adding a hydrafoil,SE4000 ,and it did nothing but screw up the steering manouverability. I suspected the motor was too low so I raised it up one hole on the weekend (The 3/4").
This morning I tested it out and it now runs at 5500 RPM at WOT and has gained 4 MPH,over 40MPH. I'm happy with that,much closer to specs it should run at. A different prop might improve it slightly,but not worth the effort. Who knew 3/4" would make such a difference and make somebody so happy?
( Insert jokes below.)

 

[Stizzla]

Ever since I bought my Grady 208 I knew something wasn't quite right performance wise. With a F225 Yamaha it should have run faster with a 17P prop and the revs wouldn't go up when I trimmed it out. I was WOT at 5300 RPM at 36 MPH. I tried adding a hydrafoil,SE4000 ,and it did nothing but screw up the steering manouverability. I suspected the motor was too low so I raised it up one hole on the weekend (The 3/4").
This morning I tested it out and it now runs at 5500 RPM at WOT and has gained 4 MPH,over 40MPH. I'm happy with that,much closer to specs it should run at. A different prop might improve it slightly,but not worth the effort. Who knew 3/4" would make such a difference and make somebody so happy?
( Insert jokes below.)

That’s what she said.

 

[Dorman Point]

Her: It looks like you moved it about 3/4”.

Him: I’d say it’s closer to 6”, actually.

 

[Original]

We’re you noticing any proposing before or after?

 

[Brando]

nice work ray, probably gained some fuel economy as well.

 

[Nahmintbay]

Keep going with it to the 15pitch. That last 500rpm in the f225 makes a big difference. I found the Mirage props to respond well in the same pitch usually a little quicker then the Yamaha sws.

 

[Rayvon]

We’re you noticing any proposing before or after?

Yes,that's why I tried the hydrafoil,but it didn't make any difference.I can use my tabs to control that.

nice work ray, probably gained some fuel economy as well.

I was thinking the same thing,it just feels right now.

Keep going with it to the 15pitch. That last 500rpm in the f225 makes a big difference. I found the Mirage props to respond well in the same pitch usually a little quicker then the Yamaha sws.

If I go with a different prop I might try a 4 blade to get some stern lift.The boat naturally rides bow high with the bigger motor and kicker etc..I've thought of calling the "Prop Gods",a guy in the U.S.A that specializes in prop selection for all models of boats.Lots more Grady's down there,so he should have a good handle on what works best for this hull and motor.I have a 13 1/4 x 17P SWS stainless prop now .

 

[Aquaholic]

Yes,that's why I tried the hydrafoil,but it didn't make any difference.I can use my tabs to control that.

Why not try the foil again after you get the right propeller and motor height combination? By using the trim tabs to try to control porposing, you are probably slowing the boat down by driving the bow into the water and making the hull operate less efficiently. The Hydro foil will help control porposing without doing that.

 

[doug78]

Yes,that's why I tried the hydrafoil,but it didn't make any difference.I can use my tabs to control that.

I was thinking the same thing,it just feels right now.

If I go with a different prop I might try a 4 blade to get some stern lift.The boat naturally rides bow high with the bigger motor and kicker etc..I've thought of calling the "Prop Gods",a guy in the U.S.A that specializes in prop selection for all models of boats.Lots more Grady's down there,so he should have a good handle on what works best for this hull and motor.I have a 13 1/4 x 17P SWS stainless prop now .

Want to try a 15 1/4 x 15 pitch? The 228 crowd loves a power tech ofs4 in a 15 or 16 pitch as per Ken at prop gods. Likely the 16 or maybe 17 on your smaller 208. Wondering if a big diameter might give you the lift your looking for.

 

[Squire]

The .com version of the Yamaha Outboards website includes performance bulletins where you can often choose a boat of comparable weight and configuration to yours. The actual performance data can be useful to narrowing down your prop choice. It takes an extra step of searching the prop by product number to get the pitch but it’s useful info.

300-225 HP V6 4.2L Outboard Motors - Yamaha Outboards

The V6 4.2L Yamaha outboard has a range of horsepower: 300HP, 250HP or 225HP. It is designed for smarter, lighter and faster offshore power for your boat.

yamahaoutboards.com

 

[Nahmintbay]

Yes,that's why I tried the hydrafoil,but it didn't make any difference.I can use my tabs to control that.

I was thinking the same thing,it just feels right now.

If I go with a different prop I might try a 4 blade to get some stern lift.The boat naturally rides bow high with the bigger motor and kicker etc..I've thought of calling the "Prop Gods",a guy in the U.S.A that specializes in prop selection for all models of boats.Lots more Grady's down there,so he should have a good handle on what works best for this hull and motor.I have a 13 1/4 x 17P SWS stainless prop now .

Yes,that's why I tried the hydrafoil,but it didn't make any difference.I can use my tabs to control that.

I was thinking the same thing,it just feels right now.

If I go with a different prop I might try a 4 blade to get some stern lift.The boat naturally rides bow high with the bigger motor and kicker etc..I've thought of calling the "Prop Gods",a guy in the U.S.A that specializes in prop selection for all models of boats.Lots more Grady's down there,so he should have a good handle on what works best for this hull and motor.I have a 13 1/4 x 17P SWS stainless prop now .

Grady’s naturally ride bow high, common is every modle, if you look at images of them running you will see what I mean. A 4 blade might help you a little, worth a test, after reading your only swinging a 13 1/4 now I think a 14 1/4 x15 will give you what your after. Never mind the stock stats from the Grady website simply having bottom paint drags you back a few mph. Again trying out a Mirage 15pitch if you come across one would be worth a try. The key is trying a few because every boat is different, fun to keep testing until you get the desired feel, if you have run a few boats you know what the feel is.

 

[Rayvon]

I'd like to try a different prop,but I didn't think dealers were willing to offer props on a trial basis anymore.What diameter range will work on an F225? I'm always trying to improve the boat cosmetically,fuel mileage,storage,dependability etc..I'm not looking for speed,just want to maximize efficiency in the power range at cruising speed.As "Nahmintbay"says you know when it "feels" right and it didn't but I'm much closer now.

 

[Nahmintbay]

I'd like to try a different prop,but I didn't think dealers were willing to offer props on a trial basis anymore.What diameter range will work on an F225? I'm always trying to improve the boat cosmetically,fuel mileage,storage,dependability etc..I'm not looking for speed,just want to maximize efficiency in the power range at cruising speed.As "Nahmintbay"says you know when it "feels" right and it didn't but I'm much closer now.

Absolutely Ray, your on the right path, the motor lift is the hard part out of the way, propping is the easy part to bring it all together. You can swing 15 diameter, I wouldn’t go bigger with your set up. On further thought I think your 13 1/4 is the Yamaha semi cleaver style? If you go up to the 14 1/4 or 15 diameter in either the SWS or Mirage you will see that they are cupped and more blade surface and that will give you a bit more transom lift that your looking for. Again any “Hunt” designed hull will ride a bit bow high, big deadrise hull under you thus the ride reputation. Agreed hard to find dealers to let you test new, what you can do is chat the few dealers about what they have used kicking around to try or a Facebook request to try. Don’t be afraid of the older style 2stroke M props they all fit your f225. In fact Evinrude Rebel with intchange hub will fit and they are good as the others. Lots of those kicking around in old stock now lol.

14 1/4 x15 pitch or 15x 15. Start there there before 4 blade hard to find any 4 blades below 15p, because a 15 4 will be equivalent to 17.

 

[Old Fisher]

Yes,that's why I tried the hydrafoil,but it didn't make any difference.I can use my tabs to control that.

I was thinking the same thing,it just feels right now.

If I go with a different prop I might try a 4 blade to get some stern lift.The boat naturally rides bow high with the bigger motor and kicker etc..I've thought of calling the "Prop Gods",a guy in the U.S.A that specializes in prop selection for all models of boats.Lots more Grady's down there,so he should have a good handle on what works best for this hull and motor.I have a 13 1/4 x 17P SWS stainless prop now .

I highly recommend Ken at Prop Gods. He knows his stuff - will want to know your current setup so he can calculate prop slip. He put me onto Powertech OFS4 for my boat and I love it. Four blade props work very well on our stern heavy fishing boats.

 

[Squire]

14 1/4 x15 pitch or 15x 15. Start there there before 4 blade hard to find any 4 blades below 15p, because a 15 4 will be equivalent to 17.

I agree that this last statement is generally true. However, when comparing Yamaha SWSII props to Powertech OFS4 a 17P was equivalent to a 17P. My path to prop selection was similar to the OP’s in that I also raised the outboard one hole then added wedges. The SWSII 17P was a pretty good match and since I wanted a decent spare anyway I ordered a Powertech OFS4 in 16P. It wasn’t enough pitch and I ended up returning it for the same in 17P. (This was with an F300).

If doug78 above had a 15 x 15 for you to try and his comment wasn’t hypothetical it might be a great place to start.

 

[Brando]

17p eco enertia if you want fuel economy 225 is lots of power on a 20’ you should be able to swing the larger prop even if you drop a couple hundred rpm on the top end but are still within the rated max range your not spending much time at 5000+rpm so focus in the 3800-4200 range where you’ll see the biggest improvement. Run this one for awhile now that the engine height is good and get a baseline for comparison.

 

[wolf]

I'd like to try a different prop,but I didn't think dealers were willing to offer props on a trial basis anymore.What diameter range will work on an F225? I'm always trying to improve the boat cosmetically,fuel mileage,storage,dependability etc..I'm not looking for speed,just want to maximize efficiency in the power range at cruising speed.As "Nahmintbay"says you know when it "feels" right and it didn't but I'm much closer now.

HHMMM sounds like a new boat in the future!!! LOL

 

[Rayvon]

HHMMM sounds like a new boat in the future!!! LOL

Nope,just making the one I have the best it can be.I haven't seen anything to tempt me YET.

 

[Stizzla]

Nope,just making the one I have the best it can be.I haven't seen anything to tempt me YET.

And when you do…

 

[Rayvon]

And when you do…

You may have to wait for me to leave this earth and go to the place where there are limitless fish,no fn fisheries,no rockfish or orca closure area's and fishing is open everywhere forever.Or one of my son's will get it.