which prop to use

Discussion in 'LOCAL KANSAS TALK' started by gdlocal10, Jan 21, 2009.

  1. gdlocal10

    gdlocal10 New Member

    Messages:
    434
    State:
    kansas
    was wondering which prop would be the best, we have a 88 johnson spl just wondering what the differences in props are.
     
  2. PHLIPS4BIGKATS

    PHLIPS4BIGKATS New Member

    Messages:
    2,679
    State:
    Alma Kansas
    If you want a whole shot prop have one with less degree pitch and if you are looking at more top speed go with more pitch. Like 13 degree versus 22degree. Hope this helps.

    Chris
     

  3. gdlocal10

    gdlocal10 New Member

    Messages:
    434
    State:
    kansas
    thank you for the input ill be looking into this and see what is best all around have agreat fish season
     
  4. GaryF

    GaryF New Member

    Messages:
    3,649
    State:
    O.P., KS
    Prop choice is complicated to the point that people really will have trouble answering your question with any specifics. There is a online calculator here http://www.watercraftservices.com/Propwiz.php?pageID=info_testimonials.php&locationID=1586 (scroll to the bottom for the calculator) that will get you into the ballpark.

    You can guess from the questions that the calculator asks that there are a lot of variables related to boat size, style, loading, etc that come into play, which is why there is no one size fits all answer for a certain outboard. To really dial it in, even the pros end up doing trial and error, watching the engine rpms and speeds achieved as they try different props with different pitches. And it is important to watch what happens to your engine RPMS at wide open throttle (WOT). Too high or too low and it is hard on your engine, over spinning or overworking it. I don't know if you have the owners manual for yours, but it should list an RPM range to target with WOT for your engine, something like 5000-5500 or 5500-6000 would be common.

    For materials, stainless steel props will usually give the best performance... I think that is because they can be made thinner, but don't quote me on that. They are also the most durable, you will probably get many years of use out of one. The downside is that they are more expensive, and the other thing is that your gears or engine are more likely to be damaged if your prop strikes a solid object. Many steel props have a hub built in with rubber or a soft pin that is designed to break free and prevent engine damage. You still have to have them repaired, but it's a cheap repair compared to a new prop or engine problems.

    Aluminum is good until it touches something solid, then it's goodbye prop blade. Composite or plastic props are about as strong as aluminum, and survive encounters with objects only slightly better.

    Most of the guys on the rivers here run stainless props. It only took me 4-5 months to destroy the aluminum prop that came with my motor, and I'm pretty careful. Mostly now I'm using one of the composite Piranha props with replaceable blades. Trash a blade and you can just slide a new one on for about 20 bucks. It definitely cost me 1-2mph on my top end though.
     
  5. gdlocal10

    gdlocal10 New Member

    Messages:
    434
    State:
    kansas
    thank you for your advice, ill be researching the web site you recomended, I see there is a little technical going on now
     
  6. arkrivercatman

    arkrivercatman New Member

    Messages:
    4,472
    State:
    KS
    Gary is right about the SS probs damaging gears if you hit something.
    My boat mechanic doesnt like them. Atleast on his boat anyways.:smile2:
    I like the idea of being able to replace the blades. Id sacrifice a few mph.
    As long as I get there I am happy.:smile2: