How do I adjust my RPM’s?

  • out_fishing
    Moorhead, MN
    Posts: 1151
    #1357672

    I have a 2004 Merc 4 stroke 75 horse and I would like to turn my RPM’s down to try to slow my trolling speed a bit. The boat is a 17 foot tiller so there should not be any reason I cant get it below 2 MPH. Currently runs about 2.5

    I have heard all it is is a screw you can adjust down. I cant find a manual online for a diagram. I dont think it can be that hard to do.

    Give me a hand

    Thanks

    Brian Hoffies
    Land of 10,000 taxes, potholes & the politically correct.
    Posts: 6843
    #1403272

    It won’t be hard to do providing you don’t mess it up. Have you tried You Tube? They tell me you can find a video for about everything there.

    out_fishing
    Moorhead, MN
    Posts: 1151
    #1403274

    No I havent looked at youtube yet but thats a good idea, it has to be on there. Im good at breaking things so anything is possible!

    blackbay
    Posts: 699
    #1403329

    I know some of the Mercury 4 strokes I’ve used, 40 and 50 hp, had many of the carb settings done at the factory and were sealed. There were no idle screws to mess with. The carb has spots for them, but would need to be drilled and tapped for a screw to be used. I don’t think Smart Craft gauges will work so I think a trolling plate or drift sock would be your best bets to slow the boat down.

    puddlepounder
    Cove Bay Mille Lacs lake MN
    Posts: 1814
    #1403345

    2.5mph is right where you should be. trolling plate, drift socks, or two 5gal pales will slow you down to .5mph without messing up your motor.

    out_fishing
    Moorhead, MN
    Posts: 1151
    #1403360

    I can back troll it alittle under 2.0 but it’s nice to go forwards on the calm days. Got a drift sock too but it’s a pain pulling in and out. You guys are probably right just to leave it and not mess anything up.

    poomunk
    Galesville, Wisconsin
    Posts: 1509
    #1403381

    If they didnt make big changes between 01 and 04 the 75 is basically the same as my 01 90hp. The is a low idle set screw on the bottom of t he throttle ‘bar’ that is the screw to adjust, NOT the individual carb. Set screws. Cant say id recommend setting it below the spec low idle speed though.

    tracker2
    Bloomington
    Posts: 19
    #1403432

    Have an ’01, 50hp Merc on a 16 foot Tracker. Trolls about 2.5 on the GPS. I have tossed out a drift sock and now get.8 mph on the GPS. Granted – a little bit of a pain to do but very reliable and I do not have to mess with the factory carb settings.

    out_fishing
    Moorhead, MN
    Posts: 1151
    #1403504

    Quote:


    If they didnt make big changes between 01 and 04 the 75 is basically the same as my 01 90hp. The is a low idle set screw on the bottom of t he throttle ‘bar’ that is the screw to adjust, NOT the individual carb. Set screws. Cant say id recommend setting it below the spec low idle speed though.


    Thanks, ill do some looking and see what I can find.

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