2001 282 w/f250's...prop size

[mleads310]

I've tried searching this to death and hoping you guys have some input. I just purchased a new to me 2001 282 with 05/06 F250's. I believe there props are the original Yamaha 15x17 when I had Yamaha tech look over boat at purchase.. But I'm going to boat to double check tomorrow. Since I purchased the boat, Max rpm is 5500 @ approx 36knots approx 39 gph (according to Yamaha gauge). Loaded or light it's always been the same at wot. I cruise around 3800 -4200 rpm depending on seas which is about 26 knots approx 21gph. Since any Grady performance numbers on my boat don't reflect F250's , I can't reference what I should be at. I know that these yams should be Wot in upper range of 5 to 6k. So I missing it there at 5500. But my fuel burn and speed seem way off. Anyone have this boat with these motors, if so what numbers are you getting and what prop are you using.

Thanks in advance

 

[Legend]

i repowered my 2004 Sailfish last year with 2017 F250's. The props recommended by Yamaha were 15 1/2 x 17. These get me 6,000 RPMs wide open and about 52 MPH. When I first for the engines the props were back ordered and I was using 15 1/4 x 19 from my old F225s. Those props only got me about 5400 RPms. The fuel burn seems in the ballpark for wide open throttle.

Good Luck

 

[mleads310]

Legend thank you for the quick response. I'm going out to the boat tomorrow and getting prop info as well as doing a 500rpm increment speed analysis with motors trimmed down and no tabs. I really want to give as much info as possible to compare with what you are running.

 

[Tuna Man]

Your numbers don't sound right... in general older outboard powered boats should consume about one gallon per hour for every ten horsepower at wide open throttle. With most outboards made after 2000 they would often consume one gallon per hour for every 11 horsepower. On some modern outboards they get as good as one gallon per hour for every 12 horsepower. That being said, with 500 hp you should be around 45 gph, but your at 39 gph. I just found the link below for reference and found the engines consumed 43.7 gph. Based on the formula I mentioned your engines are only producing about 429 hp (39 x 11).

I 'd use this for reference:
http://www.yamaha-motor.com/assets/prod ... 50txrd.pdf

At 35 knots, your doing 41.4 mph, that is way below where you should be with twin 225 hp and even worse than with 250 hp. A bunch of questions for you, what condition are the props in? Is the boat painted and what condition is the boat bottom in? Are the fuel filters clean and the gasoline fresh? Have the engines been tuned recently? Are you making sure the trim tabs are fully retracted and the engines trimmed up as far as possible when doing your tests?

 

[Ratical]

I to researched the whole prop thing this spring and had similar numbers with a single Yamaha 250. I am currently running a 24ft grady offshore and feel your pain...... My cousin fishes out of lower Alabama and is a pro staff for power-tech props. He told me to call them with my performance numbers and they would tell you exactly what i would need. I did and they hit it right on the chin. I never saw 6000 at wot, best i could get was 5600 at wot and my fuel burn was like 24 gph. My cruse was between 4400 and 4600 depending on the seas and my burn was 14gph and i to was running a 15x17 3 blade Yamaha prop. I also had to run lots of tab because the boat ran very bow high.....

They told me to to run a 15.25X16 four blade and the boat really preforms.I'm now at 6000rpm wot,at 21gph and cruse at 4100-4200rpm at 9.5gph, i run no tabs because the four blade creates stern lift and my fuel burn at cruse is 9.5gph. I did loose a couple MPH but i like the economy!!!!!
PowerTech! Propellers, Phone (318) 688-1970

 

[mleads310]

I went to the boat yesterday expecting to do a trial run with rpm, gph, mpg etc but weather wasn't cooperating. I did identify the prop which is a Yamaha 19-M.

The outboards have been serviced by a certified Yamaha tech a couple of months ago, everything from belts, tension sensors, plugs, filters, etc top to bottom. I have ablative paint on hull. Hull is is pretty good shape itself. I ran the previous numbers with no tabs and the engines trimmed up as high as possible without causing the props to slip (about 3to4 bars on Yamaha tach). Condition of props are pretty good with only a very minor Nick on one blade. I was able to find the Yamaha reference numbers with these outboards and this boat.... I'm not getting any where near them at any rpm.

 

[mleads310]

Forgot to post. The bulletin shows the following props being used in test

15-1/4 x 19 SWSII
6D0-45970-00-00
6D1-45970-00-00

I'm not sure if my 19-M is the same because a Google search just tells me it's discontinued

 

[wahoo33417]

Valentines day was first calm day in a while, so no fishing, so just a nice cruise with the Admiral. However I did get to run (the boat) wide open for a bit.

2007 282 with 2007 Yamaha F250's hit 5900 rpm with 3/4 fuel. That got me about 46 mph on Yamaha SSW II props, 15 1/4" X 19". Boat has bottom paint in rough shape.

I don't believe the 282/F250 combo is over-propped with 19" props. She hops onto plane just fine.

Rob

 

[Legend]

Forgot to post. The bulletin shows the following props being used in test

15-1/4 x 19 SWSII
6D0-45970-00-00
6D1-45970-00-00

I'm not sure if my 19-M is the same because a Google search just tells me it's discontinued

If I recall the m 19 is on the outside etched in the stainless. I think the size is etched on the inside of the prop on the prop face that is toward the engine so u have to remove the prop to get the size

 

[mleads310]

I recently switched my m-19's to a pair of the same props I had as spares, but had them refinished to compare numbers. I also did this while my boat was being worked on the other week, so clean painted bottom. I ran the new props in somewhat choppy weather, wind at 5-10kts, against the tide, 2 people, light gear, 80 gallons of gas. Good news was I was able to hit 5900 rpm, but still could only Max out at 45mph. Maybe because of wind and slight chop? Also good news I was able to cruise with much better efficiency, I believe I was around 3900-4100rpm, aprox 29mph, aprox 17-18gph. Which even in perfect conditions I don't believe I achieved with the other props (maybe those small dings really made a difference)?. Also for reference outboards mounted per Grady spec and second to top hole.

 

[amf282]

We had 250's on a 2007 Sailfish, 15 1/4 x 19 3 blade props. Same numbers as you posted above. We'd run 5900 WOT and get about 47 mph. Loved to cruise at 4200-4400 rpm to get around a 1.6 mpg burn. Trim up a little more and you will get a little more speed.

 

[mleads310]

Thanks amf282, that's what I'm thinking too, I'll trim up a bit more. . I'll take another run if weather holds this weekend and report back.