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My Poor Prop

Discussion in 'Pontoon Forum' started by Dennis T., Sep 26, 2017.

  1. Dennis T.

    Dennis T. Member

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    Here are the pics of my prop. hit a rock running around 4000 rpm. no other apparent damage, and amazing only lost 1mph off of cruising speed. alot of questions, especially considering my previous ones around top speed. first off:
    *repair or replace prop? i have heard both, i think i will see if this can be repaired, and then also buy new in the spring
    *Lower Unit? no new noise or damage other than a nick in the skag (sp). i need the toons cleaned and a marina here will pull the boat. i will have them check it and see.

    http://s61.photobucket.com/user/DandDT/slideshow/prop

    **top speed. these pics show more of the numbers on the prop than the damage. the point is this is a 14.5 x 15. I assume the 15 is the pitch. the previous owner was a big skier and wanted hole shot above anything else. i also assume this prop traded top end for low end to that end. so a larger pitch will go the other way? what is a good middle choice?
    Thank You! DT
     
    Last edited: Sep 26, 2017
  2. Dennis T.

    Dennis T. Member

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    Oh yeah, the pic of the motor mount. as you can see it is in the top hole, meaning the motor is all the way down. that was one of the questions when we were discussing top end. DT
     
  3. BigKahuna

    BigKahuna Well-Known Member

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    Is there a vibration now that your prop is damaged?!? If not just keep using it until the off season. Never had a stainless prop fixed so I have no idea how much that will run. Good thing there is no damage to your lower unit. The stainless props don't "give".

    Looks like the "skeg" almost did its job by taking some of the damage away from the prop.........
     
  4. lakeliving

    lakeliving Well-Known Member

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    I raised mine one hole. Slightly better top end but my sharp cornering suffered slightly. Worth it for my use.
     
  5. ImTinkerbella

    ImTinkerbella Well-Known Member

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    Wow, Dennis, that is painful to look at. I'm so sorry. :(

    While it doesn't share the vintage sawmill blade appearance of our own shredded prop, I can see (without having any real experience or knowledge) that your prop was SS where mine was aluminum... so I know that there are more things to consider (outside of the cost).

    Hope it works out better than you may fear...
     
  6. Dennis T.

    Dennis T. Member

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    Thanks All, No vibration that i can tell, but i have only had this boat for weeks, not even a month so may not be able to tell. Nothing obvious, I will still get the LU checked out. The sound was horrible, so i was expecting a Tinkerbella result, but maybe I got lucky.
    LakeLiving: thanks for the feedback, good to know. If i go for more top end i will most likely do it with prop and not motor relo based on your result. we tube alot and sharp corners and donuts is where i get to have fun throwing them off so i need my corner speed :). back to prop i will see if my assumptions are correct and possibly get a higher pitch prop to get more top end, but not too much as the hole shot does feel strong.
     
  7. mattb

    mattb Well-Known Member

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    Get it repaired if they can and use for a spare and buy a new one.
     
    Dennis T. likes this.
  8. Remediation

    Remediation Well-Known Member

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    My 3 blade SS with slight damage was $65 to repair.

    The 22' boat has a seat on the front of the helm. Our friend was sitting on it talking to me and I never saw the buoy I ran over at speed.:(
     
  9. cwag911

    cwag911 Moderator

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    If you have a 15p prop now, you don't want more pitch. You'll only go slower.
     
  10. Dennis T.

    Dennis T. Member

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    thanks CWAG 911, any more info on props you can share? in laymans terms how does diameter and pitch impact hole shot and top end? thanks again. DT
     
  11. Spoiledrotten

    Spoiledrotten Well-Known Member

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    Think of a go cart. If you have just so much engine (5 HP), and you have an 8" tire on it, you'll most likely do what it's intended and designed to do. Now, if you remove the rear tires and put 25" car tires on it, that 5 HP motor is going to suffer greatly, trying to turn those huge tires. The more mass you have, the harder it is to make that mass go, so you need more power to turn it. You will suffer greatly at the hole shot, but it will actually go faster if you could get it up to a decent speed, it would probably go faster than the little go cart tires. That's as laymen as I can probably get. :)

    You can't take a prop off of a 200 HP boat motor, and put it on a 45 HP motor and expect it to do anything but bog the motor down. Smaller diameter prop and lower pitch means less power to turn it, plus it raises your RPM in doing so.

    I hope the go cart example wasn't too stupid sounding.
     
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  12. Tooner

    Tooner Well-Known Member

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    I can't chime in on the cost of prop replacement, or repair. However, I can address the "top speed and top mount hole" discussion. I have the exact same prop you do on our 21 SLX with 150 Yamaha and SPS. When delivered, our boat's top speed was 44.1 mph as verified by our Garmin DV54. Also, there was a relatively wide range where the trim affected speed and ride attitude. But, one thing I was not happy with was the amount of speed I was losing when making high speed turns. Also, when doing this, the prop tended to cavitate unless I trimmed down. I thought that was "the norm" and continued to enjoy the boat, although we spend a lot less time at top speed than leisurely cruising of speeds up to 25 mph, which is the normal speed limit on our river. Inspection by me showed the motor was mounted in the third from the top mount hole. Oh, btw, our Yammy has a 25 inch long shaft.

    When the dealer replaced the center toon due to it leaking, the motor was reinstalled in the top hole. I questioned the master mechanic at our dealer and was told that the top was the recommended position by Bennington. More importantlyhe told me that at this position, the anti cavitation plate on the motor was exactly even with the bottom of the pontoons, which is where Yamaha suggests it to be.

    What I've noticed since getting the boat back is that my top speed has dropped to 39 mph, or just over 5 miles. The RPM have also dropped from 5900 to 5600. However, now the Benny turns MUCH better at high speed, and the prop no longer blows out and cavitates. Also. The trim has become a lot less sensitive and the boat just seems to ride better. Maybe all the experts at Bennington and Yamaha know what they are talking about. (Sarcasam font needed, because the folks that build this stuff truly are the experts!)

    So, I am happy to have the boat in its new and correct state of rigging. The ride and handling certainly justifies the loss in top speed. (Btw, I do have pictures of my prop, and motor mounting before and after toon replacement, but posting them would not serve a big purpose.)
     
  13. ugleeual

    ugleeual Active Member

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    Good info thanks
     
  14. Dennis T.

    Dennis T. Member

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    toon and spoiled-r; thank you both. good stuff. I appreciate the analogy from SR and all the rich details from tooner. this is much clearer to me now. from what i read the top hole should be good and gives me better cornering, less cavitation, and takes a few MPH off the top. I will stay with that set up. I will get the toons cleaned and repair the prop if possible. I will assess the performance then and when i buy a new prop in late spring consider a change to bring back a little top end. ONE QUESTION: to do what i said in the last sentence (new prop), am i on track that a slightly higher pitch will do that, give me more top end but give up some hole shot. that is my thought now. thanks again, DT
     
  15. myv10

    myv10 Well-Known Member

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    The higher the pitch the faster the boat will go at top end, within reason of course, acceleration will be slower to reach that higher top end.
     
  16. cwag911

    cwag911 Moderator

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    If you have a 22' or 23' boat with a 150 on the back then a 15p is as large as you'll want to go. If you go bigger, the boat will go slower. Unless you have a Suzuki which has a different gear ratio.
     
  17. PJatLOTO

    PJatLOTO New Member

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    Dennis,
    Had a stainless prop, 3 blade fixed for $95. Yours does look worse than mine did. Just for reference, the rubber clutch was $95 as well (different incident). A friend of mine busted 1/2 the skeg off of a Yamaha 200 - $100.

    For the lower unit, if you have run it some and are able, you could pull the plug and see if you have water in it or check for metal shavings.
     

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