prop advice Yamaha F225

Discussion in 'Boats, Motors, Trailers and Towing Rigs Forum' started by Wondermur, May 21, 2020.

  1. Wondermur

    Wondermur Member

    We have a 2003 F225 with 17" pitch 3 blade s/s prop. It is a (edit) 17-M. Yamaha prop. Boat is a Double Eagle 206ext. We have run this prop for 6 years and it is OK. I would like to try a 19-M prop or something similar. I have some numbers for you guys and hope to get some suggestions and thoughts on a good prop for this boat.

    In Up to a 1.5 foot sea swell with 2 people on board the boat weighed about 4300lbs which is about as light as we run it.

    1st speed test with 17-M prop
    3500Rpm - 23.5mph
    4000rpm - 28.5mph
    4500rpm - 32.5mph

    2nd speed test with 17-M prop
    RPM MPH
    3000 13.3
    3500 23.5
    4000 27.5
    4500 30.8
    5000 35
    5500 38.3
    6000 42.7
    6100. 44

    We bought a 4 blade aluminum prop 19” pitch and tried it out for a couple of hours at a lake years ago but performance was worse, so hoping to do better this time.

    I feel like if I got the same prop with higher pitch, performance should be predictable - a bit faster and similar low planing speed?
    We have trim tabs.

    What do you fellas think?

    Following some advice Here I will see if I can track down a used prop on the buy/sell forum? Then sell the aluminum prop and keep the 17-M for backup.

    Thanks
    Wondermur
     
    Last edited: May 22, 2020 at 8:44 PM
  2. profisher

    profisher Well-Known Member

    The important factor is are you running heavy most of the time or light? A higher pitch prop will give you a higher top speed but will make getting out of the hole more difficult for the engine. So if you are running heavy most of the time, not the best situation. Would be like dumping the clutch from a standstill, on a hill, in 3rd gear instead of 2nd. Also if most of your use is on the ocean...max speed is not important at all as most of the time you can't run it. If you are pulling skiers...again a lower pitch/gear is better and easier on the motor and they get up quicker.
     
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  3. Wondermur

    Wondermur Member

    Yes we run in the ocean mostly.
    The 17 is great for waterskiing. It’s not a heavy boat for a F225. Illustrated by it hitting the rev limiter at 6100rpm. If we are running heavy we would be at about 4800-5000lbs.
    Thanks
     
  4. Pineapple Express

    Pineapple Express Well-Known Member

    Prop selection is complicated...way more complicated than just looking at the pitch number or number of blades.

    The first goal of selecting a prop is to have the right pitch so you reach the manufacturer's recommended wide-open-throttle (WOT) RPM range. The Yamaha F225 is rated for WOT RPM of 5000-6000. Usually it is recommended to be able to reach the upper half of the range under normal boat loading (fuel, gear, people, etc). So your current 17" pitch prop is getting you there, but if you can hit the limiter maybe you do want a bit more pitch. One option is to have your existing prop re-worked to add pitch. There's a shop in North Vancouver called Osborne Propellers that can do this for you.

    If you're looking for a new prop (which you indicated that you are) you may want to look for props that have stern-lifting characteristics. These are usually props with lots of blade area and longer exhaust tubes. Often 4-blade props do provide stern-lifting characteristics which is why they're frequently recommended for fishing boats with kickers and gear at the stern.

    One popular prop for your use is the Powertech OSF4
    https://www.ptpropeller.com/content...wertech_ofs4_stainless_propeller_mercury.html

    Note that is says for Mercury, but with the right hub kit I believe this can be installed on the Yamaha.


    Is this the prop you're currently running??
    https://www.greatlakesskipper.com/y...nless-steel-3-blade-right-hand-boat-propeller
    Another option would be going to the Yamaha Saltwater Series or Series II props. I run a Saltwater Series prop on my Yamaha F250 and it's a good all-around prop. I find that it breaks loose in corners and it takes a moment to bite back, but I haven't tried other props to compare.
     
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  5. Pineapple Express

    Pineapple Express Well-Known Member

    The other variable to make sure you've dialed is the engine mounting height. Often motors are mounted too low from the factory. On our boat we raised the motor one hole from the factory mount...we did try 2 holes up but settled on one hole up. Generally you want the ventilation plate visible above the water when running. It will be getting splashed obviously, but the ventilation plate should just be skimming the water surface. The mounting height will be slightly dependent upon the prop selected but no matter what you don't want the engine buried in the water when running.
     
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  6. Olde School

    Olde School Well-Known Member

    I have a boat of similar length and mass, with similar power.
    During my prop selection phase it soon became evident to me that my number 1 parameter was hole shot, closely followed by cruising fuel efficiency.
    A SS 3 blade 17" was the best compromise for me.
     
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  7. ericl

    ericl Well-Known Member

    The website www.boatdiesel.com has an "advanced prop calculator" that let's you model various parameters including increasing/decreasing weight of your boat.

    You enter your boat's parameters, length, weight, known top speed, etc & then choose from a database of engines (they are all diesels BTW), gear ratio's the prop pameters - pitch, diameter # blades.

    I have tried w/o success to find a similar calculator for O/B's, but choosing a high RPM 225 HP diesel should give good results.

    Downside is that access to the calculator requires a $50 US yearly membership.
     
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  8. beemer

    beemer Well-Known Member

    I would try a higher diameter prop and leave your pitch at 3 blade 17". if you bump up to a 16 diameter you will get better hole shot and good fuel efficiency. As Pineapple express says mounting height is also key.
     
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  9. Wondermur

    Wondermur Member

    Thanks Pineapple Express.

    I went down to the boat today and took a photo of the prop and it is a 17-M, not a 17-T as I initially wrote.

    026F463A-1BA0-4CEF-9C57-F31DF9C45B5F.jpeg

    We had the rubber hub replaced on it 6 years ago I think at Osborne’s. This prop came with the boat.

    Appreciate everyone’s advice

     
    Last edited: May 22, 2020 at 8:49 PM
  10. Wondermur

    Wondermur Member

    Hmm. Ok. Holes shot is good currently. I was thinking if we went up to 19” the fuel economy would improve as the revs at say 30mph would drop from 4500 to about 4200...and hole shot would be not as good... Also wide open throttle would be down to about 5700-5800rpm, rather than 6100 at the limiter...
    Appreciate your thoughts.

     
  11. profisher

    profisher Well-Known Member

    Less revs doesn't always mean less fuel. You can be running 4500 rpms with less throttle applied because the motor it turning easier with less load....and running 4200 rpms with more throttle applied to hold that setting.
     
  12. Wondermur

    Wondermur Member

    Yes that makes sense.
    I guess I want to be able to go faster?
    And hitting the rev limiter makes me think I could go up in pitch and not sacrifice too much?
    Also I told you the wrong prop and have Edited the post after going to the boat today.
    It’s a 17-M Yamaha.
    Cheers
     
  13. Pineapple Express

    Pineapple Express Well-Known Member

    Agreed with @profisher about the loading of the motor.

    What other markings are on your prop @Wondermur ? The pic doesn't show the blades very well so it's hard to tell. I think you may have this prop with the paint brushed off?
    https://www.amazon.com/Yamaha-Prop-Propeller-6G5-45947-01-00-6G5-45947-01-98/dp/B005C5BFJI

    Look in the hub area where the prop nut is to see the markings...you need to know the diameter and pitch. But be careful comparing one propeller model to another because they're not directly comparable....prop selection is often a trial-and-error process.

    Check the engine height to confirm you're in the right zone before doing prop trials because if you're buried you may wind up having to get a different prop after adjusting the motor height.

    This might be too much pitch but it's a local seller so maybe you could do a trial and return or ???
    https://vancouver.craigslist.org/van/bpo/d/vancouver-stainless-steel-propeller/7128320414.html
     
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  14. brutus

    brutus Well-Known Member

    Be careful what you wish for, a friend of mine sort of did what you are looking at doing, campion 682 with a 250 yamy, went from 17 to 19 pitch, ok he gain more speed 3 mile an hr at same RPM,BUT as soon has he get people on board like 2x so 4 on board the thing is a slug to get on plane, sort of like they all need to go to the front of the boat to get on step and he did not gain anything, actually he lost 700$ for a prop that did nothing lol. Also when we go offshore me in my boat he on his,he as issue with big fallowing tides, he need to stay floored to stay on plane, as soon as he ease up on the Trotel The thing just bogs down, or he is going way to fast and goes flying and take a beating. Myself went from an 14”3/4 x18 3 blade ss to a 14”3/4x15 four blade ss, i get up on step in any condition, can stay there at lower speed and way cheaper on gas. Again there is a but lol, where i fish going over 30mph most days will get you nothing but a beating. So depend what you wish for
     
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