Trophy Sport pitch question

Discussion in 'Boats, Blinds, & Gadgets Forum' started by cjc16, Aug 16, 2017.

  1. cjc16

    cjc16 New Member

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    Ok so I called powertech today. They recomended the SRD4 (4 blade with 11.25 diameter) in a 13p. My first response was "can my 50 4stroke turn that," and he said that it being a 13p it would have no problem. Said they put the SRD3s (3 blade,11.25 diameter) on boats/motor combos like mine all the time.

    Thoughts?
     
  2. muddywater

    muddywater New Member

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    I got the PM for input on Trophy Sport.
    If your hole shot got worse, it is because you have too much pitch and you switched to a 4 blade. As a general rule you should pick the 4 blade with 1 inch LESS pitch than a properly pitched 3 blade. It kind of sounds like your 3 blade had too much pitch for your boat/engine combo so you just made it way worse with the 4 blade. Either one would probably work fine if you got one with less pitch.

    I had been switching back and forth between a 15 pitch Mercury Vengeance which was propped perfectly for my old 1992 2-stroke Mercury 40 and a 15 pitch Trophy Sport, but the 15 pitch Trophy Sport is really too much prop for my engine. It dropped my rpms to about the same level they would be if I was running a 16" pitch vengeance, so for my boat I really should have gotten the Trophy Sport in 14 pitch (which is why I had put the 15 pitch one up for sale). I knew about this when I ordered the 15 pitch Trophy Sport, but I was adding a jack plate and thought that I would be able to run the engine a little higher and get my rpm's back, which did not work. With the jack plate on my boat I lost speed and too much water pressure by raising the engine further, but did did allow me to run quite a bit shallower. The reason I had gotten the Trophy Sport when the Vengeance was already propped perfectly was that the Vengeance blows out like crazy on some of the super curvy bayous I was running. I recently had more cup added to the Vengeance which fixed the Vengeance blowing out problem, but I lost a lot of performance (adding cup effectively increases pitch and dropped my rpm's too much, so too much cup can be a bad thing). As a result I started running the Trophy Sport for now which still performs pretty well despite the fact that I really need to go to one with one inch less pitch.
     
  3. cjc16

    cjc16 New Member

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    Muddywater... thank you for responding! Yes... I made a rookie mistake with the 4 blade. I was able to run a 14P Vengeance and it was much better holeshot and I never hit the rev limiter on the top end (don't know the speed). So I actually think I would need to drop to a 13P TS, if I even get another TS. I've been talking to PowerTech and they have me talked in to wanting a larger diameter prop for holeshot for loads and rpm control when I'm not loaded, as I mentioned before your post. I may also try to vent my 15P 3 blade and see what that does. Apparently that helps the 4 strokes on the low end torque. If that works well, I may be brave enough to do it to my TS. Although the TS is basically brand new, so I could sell it very easily I'd imagine.
     
  4. muddywater

    muddywater New Member

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    The best thing you could do before spending any more money is get a tachometer and check your rpm's before putting any more money into props because it can get really expensive really fast. Increasing prop diameter can improve hole shot, but it can also reduce rpm's if you are running the prop buried. If you are running the prop really high or surfacing, it might not be detrimental to rpm's. If it is a real barge of a boat the large diameter prop might help, but I would not buy any more props until you find out your rpms. If pitched too high, a large diameter prop would just make things worse, because the smaller prop would at least slip a little and gain some rpms, but the large prop will slip a lot less and would lug the engine if it is overpitched. You might also consider the black Yamaha props which 1995 US1 is always recommending. I have been itching to try one myself, but Yamaha doesn't give those babies away.
     
  5. cjc16

    cjc16 New Member

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    Alright here's an update on my situation...

    Got the VesselView and man is it sweet! Today with only me in the boat and my 15p QS (Vengeance) I ran 5400rpm and 38.5mph @ WOT.

    If the widely used formula of 200-250rpm per pitch change is true, then if I drop to a 13p I should be pegged out (max rpm = 6000). Which is what I'm looking for since this will be a hunting prop for load pulling and shallow water.

    Thoughts anyone? Thanks!
     
  6. muddywater

    muddywater New Member

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    Sorry, I have not been back for a long time, but your conjecture that dropping to a 13pitch sounds pretty close. I bet it will jump up on step like a different boat with a 13pitch. If it is a barge of a boat, increasing diameter may help also as it did for me when I switched to a much heavier boat with the same engine. How did it end up turning out?
     

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