Help choosing a prop

Discussion in 'General Open Forum' started by coastal creeper, Apr 27, 2020.

  1. Anyone recommend somebody in Vic to help me choose the right prop for my boat. I’m running a Yamaha 115 on a Malibu 182. Does about 25mph at 4300rpm. When it’s a full boat it has a hard time getting up on step
  2. fish brain

    fish brain Crew Member

  3. Thanks brain
  4. ReelSlim

    ReelSlim Crew Member

    Do you have a HydraFoil on it or just stock? I had the same boat with a 115 Honda that is heavier than the Yamaha. I put an SE200 Foil on it and it made a huge difference with lift and was cheap. I know there are a lot of Foil haters out there but I had them on my last 2 boats and for those set ups worked well. You can go with 4 blade props to get some lift but with a 115 it might be a bit shy on power. I also kept a few spare cannon balls up front in the anchor locker along with a fair bit of chain...anchor and rode for a safety anchor. (Not a full Hali set up)
    Last edited: Apr 28, 2020
  5. Foxsea

    Foxsea Well-Known Member

    You may have too much pitch. Will it run up close to 6000 rpm at WOT? Check with the experts but I have a F115 on a Malibu Tyee. The prop has a 15 pitch and the boat jumps
  6. Hopefully the winds are down this weekend and I can try to get my wife open throttle reading while on my way to a Ling spot ;)

    good call, the prop experts will want that info

  7. I’m def not opposed to a foil. I will however make sure I’m running the appropriate prop first tho. We’ve only had the boat for a couple months so still getting it dialed in.
    ReelSlim likes this.
  8. donnie d

    donnie d Active Member

    If you figure out how to get your wife open throttle, let me know buddy
    agentaqua likes this.
  9. Fixit

    Fixit Well-Known Member

    Who doesn’t love a fully throttled open wife??!?

    seems like she’s over propped I’d guess. Need to get wot rpm into spec
  10. ratherbefishing

    ratherbefishing Active Member

    I had this boat with a Honda 115 which is heavier than the Yamaha. While I don't have the boat anymore and I can't remember what pitch I ran, what I can say is adding a set of trim tabs (I installed Bennett) made a world of difference. Not only did it get things up on step faster, but it kept things on step with much less effort.
  11. Ya I’ve got trim tabs. I’ve only had one opportunity to see how it handles in rough weather and it’s really cool how you can keep a boat on plane at low speeds. I think I was doing 18mph still on plane.

    For your tabs to help get up on step do you just fully engage them before giving your wife... I mean motor throttle?
    Fixit likes this.
  12. Northcst

    Northcst New Member

    Sounds like your over propped and/or the engine isn't running well. What details do you have on the prop?
    For reference and it may help others with the same setup...
    I've tested 3 props (4 if you include the older 115 motor) on a Tyee 17 with a newer Yamaha 115. These were done with a full tank, 9.9 Yam kicker, dual batteries,2 people and a medium/light load with the top up.
    The white aluminum Yamaha cleaver style 13 1/4" x 17K, 64KPH @ 6200 RPM and would easily allow the motor to rev past the 6300 red line. these props typically come stock, are cheap and perform ok in comparison to what's available.
    Aluminum Talon GP 13 1/8" x 17", 71 KPH @ 6200 RPM. With this combo this motor can rev to 6300 trimmed up until just before blowout.
    Aluminum Talon GP 13" x 18 " , 72 KPH @ 6200 RPM. With another passenger and prawn gear I was able to hit 70 KPH @ 6000 RPM.
    In my case the Talons outperformed the cleaver at all RPM's with less blow out once your out of the hole.
    Your rig is heavier and may compare more closely to a Double Eagle 18 with a 115 Yamaha in weight and prop performance.
    I'm currently on the lookout for a SS Turbo FX4 in a 16" pitch or performance series SS prop GYT 16 13.25 X 16 to try out.
    Good luck finding the right prop. It shouldn't difficult to get her running well and it's a nice hull to work with.
  13. Cuba Libre

    Cuba Libre Well-Known Member

    I am suprised that you have trouble getting on the step. While I have a 20ft Aluminum boat, with a Merc 115 4stroke and a 9.9 kicker, I can still get up easily carrying three guys, all gear , 200 liters of gas and a large cooler loaded with ice at the stern.....and cruise at 21-24 mph. Never go over 4400. Never have to tell the passengers to move forward. The prop is a compromise...Aluminum .... Gets up out of the hole quickly while carrying a load, but has a lower speed at WOT., Its a Turning Point 13.25 x 19... 21431911 They do make a prop for a Yammie. Hope this helps.
  14. Thanks for the replies fellas. We finally got our wide open throttle reading... tough thing to do with these winds in Victoria haha. Got up to 5500 rpm.

    I feel like we’re going to try and tick all the boxes in terms of tuning up the engine. Our boat was owned by 2 old guys before us and I don’t think it got used a whole lot. Great for some reasons but I don’t think motors like to sit.

    once we’re confident the motor is running as it should we’ll look further into prop. The only markings I can see on our current prop is 17k. And I think it’s a 13”.

    for getting the engine tuned up the things we’ll try doing is: check plugs, fuel filters, fuel injectors. Any other obvious ones I should be checking?
  15. Northcst

    Northcst New Member

    Cheap insurance to have the motor scanned.
    It may be a 13" X 17 " pitch which may or may not be too much depending on prop design. Try a search on motor setup as motor height can be a factor in how the boat performs in addition to the prop installed. If the ventilation plate is running too deep or shallow it can cause issues on some hulls.
    Yamaha ring free or another fuel conditioner can help clean her out if you don't already run something in the tank and I'd try Foxsea's suggestion or consult with a prop shop if everything else fails.
    Last edited: May 23, 2020
  16. CatchAll

    CatchAll Member

    Also make sure that the motor is high enough on the transom. When you are on plane the anti ventilation plate should be skimming the surface of the water. When I got my boat the motor was mounted a couple inches too low and performance was terrible. After I raised the motor to the bottom hole on the bracket it was like a different boat.
  17. Northcst

    Northcst New Member

    Mind me asking which hull you have. I've considered raising mine but have found the Double Eagle style hull can be sensitive to ventilation when the motor is run much higher than a near level vent plate height with the props I've tested(mine is 1/8"higher).
    Some hulls perform much better with the plate higher than level. Props with more cup and rake or 4 blade can be less susceptible although as with tires most props are a trade off.
    Once you're on a plane how far up can you trim the motor before the prop loses traction or vents?
    PS I'd put thermostat near the top of things to check while doing preventative maintenance.
  18. CatchAll

    CatchAll Member

    I have an older campion explorer 185. When I got it the vent plate of the motor was about 2” below the bottom of the transom if you ran a straight edge off the transom/keel. It would spray lots of water, porpoise, burned a lot of fuel, and had trouble reaching full rpm. I raised the motor one hole at a time and test drove after each raise. With that motor I got to the bottom hole on the bracket and it ran better each time. When I switched motors I put a manual jack plate on to make fine tuning the motor height easier. Now I can crack four bolts loose and crank the motor up or down without a hoist.

    Right now the vent plate is a bit higher than the bottom of the transom, but the jack plate set the motor back about 4” which makes a difference as to what motor height will work best. I haven’t had any traction or ventilation problems running straight or turning hard, but I only trim up far enough for the boat to run right. If I keep trimming up the boat starts to porpoise before it ventilates. I think trial and error is the best way to tune in your motor height. You’re correct that hull design, prop design, etc all make a difference.

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