prop ?

Discussion in 'Boating' started by yellingrebel78, Oct 30, 2009.

  1. yellingrebel78

    yellingrebel78 New Member

    Messages:
    455
    State:
    georgia
    I got a 15 ft boat with a 1974 mercury 500 50hp motor it's running a 17 pitch prop on it right now my ? is that a good pitch to run rivers with. The boat is aluminum and probally weighs about about 1200 lb person and gear and all. If it is not a good prop what pitch would yall suggest.
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Thats a good size for the load you are carring for lake or river. To be sure you are useing the right prop you will have to run a tach on the engine.That will tell you if you are running in the right RPM range
     

  3. yellingrebel78

    yellingrebel78 New Member

    Messages:
    455
    State:
    georgia
    k thanks I don't know much about boat motors I'm in a learning process do u have to have a certain kind of tach or can I put an automotive tach on it since it got a distributor
     
  4. Ken G

    Ken G New Member

    Messages:
    12
    A generic automotive tach will not work on your outboard. Outboard tachometers receive their signal from the stator. Your '74 has the Type II ignition which uses an 8 pole stator and you would set the tach to receive 4 pulses. My '77 Merc 500 has the Type V ignition and the stator has 12 poles and the tach setting is 6. The tach setting has nothing to do with number of cylinders, it is based on the number of negative pulses from the stator (half the poles).

    You can however use an automotive inductive tachometer which uses the pickup which clamps around a plug wire. The problem with these is if the pickup wire is short you have to run down the river hanging over your transom which I wouldn't recommend.

    There is a company called Tiny Tach which sells several different inductive tachometers which can be permanently or at least semi-permanently mounted. I think they run $35-$40.

    A genuine Mercury, or an aftermarket like Teleflex, tach will plug into the connector at the front of your MerControl if the connector matches. I don't know if the original connector harness would still be available due to the age of the motor.
     
  5. yellingrebel78

    yellingrebel78 New Member

    Messages:
    455
    State:
    georgia
    the biggest thing is my motor doesn't have a stator at all. This motor didn't even come with it. Don't even have a starter yet.
     
  6. Ken G

    Ken G New Member

    Messages:
    12
    If it runs you have a stator. The stator is beneath the flywheel. It makes no difference if you have a manual start or electric starter you will have a stator.
     
  7. yellingrebel78

    yellingrebel78 New Member

    Messages:
    455
    State:
    georgia
    it don't it got a distributor all the stator is for charging I don't even have a battery hook to mine all I got is a kill switch to shut it off works like a lawn mower it grounds the ignition out
     
  8. Ken G

    Ken G New Member

    Messages:
    12
    OK you got me there. I rechecked the book and found that the manual start Merc 500 does not have a stator. You would still use an outboard tachometer and connect it to the brown and black wires in the MerControl. I don't know what pulse setting you would use.
     
  9. yellingrebel78

    yellingrebel78 New Member

    Messages:
    455
    State:
    georgia
    k i geuss i see if i can find one
     
  10. gotta go

    gotta go New Member

    Messages:
    2,395
    State:
    SC
    I'm fortunate enough to live close to someone that rebuilds props. He can tell you the pitch you need by looking at your old prop, outfit. I guess he has been doing it so long he just knows. I wish that worked all the time with wives and catfish:big_smile:
     
  11. yellingrebel78

    yellingrebel78 New Member

    Messages:
    455
    State:
    georgia
    ok got me tach hooked up now didn't realize they was one on the boat I got the motor off of . which was the one for that motor I forgot all about it till my dad mentioned something about it I feel like a fool but what should I be running on when at full throttle.
     
  12. Ken G

    Ken G New Member

    Messages:
    12
    WOT (Wide Open Throttle) for that motor is 4800-5500 rpms. I'd shoot for the upper half of the range if possible.
     
  13. playin4funami

    playin4funami New Member

    Messages:
    4,104
    State:
    Saronville Ne.
    wide open right near 5000 rpm,would be as much as I'd want to push it. Any higher you risk motor damage
     
  14. yellingrebel78

    yellingrebel78 New Member

    Messages:
    455
    State:
    georgia
    just got back with it and at wot it was pushing 2500 rpm I think I got to adjust the advance screw alittle more I cleaned the carbs already and adjusted them I set the timing on it not exactly set as far as it suppose to be like 3 degrees ye to be right on its hard to adjust it when you running it in a barrel I geuss next time out I'm going to adjust on it while I'm running but the only problem I cant use a timing light