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  1. #1
    Join Date
    Mar 2008
    Timmins, Ontario, Canada

    Default "I have a 4 hp Johnson 1972 we

    "I have a 4 hp Johnson 1972 weedless model 4W72S, ser # 48996 does it have points? It won't idle properly but runs fairly well at top speed (which is not fast HaHa). What shoud the gap be is I have them? Could a crank seal cause this problem? The carb was cleaned a few times already and new plugs put in."

  2. #2
    Join Date
    Feb 2001
    Central West Florida

    Default "Spark plugs should be Champio

    "Spark plugs should be Champion J6C plugs, gapped at .030.

    Yes, the engine has points. Set as follows:

    (Point Setting Of Magneto Models)
    (J. Reeves)

    Set the points as follows. Have the flywheel key aligned with the fiber rubber portion of the ignition points. Adjust the gap so that a .020 gauge will pass thru but a .022 will not. Should there be any question of the points being dirty (touching the contact with your finger would cause them to be dirty), clean them with a small brush and acetone or lacquer thinner.

    NOTE: Should the operating cam have a small portion on it with the word "SET" imprinted, align this portion with the fiber rubbing portion instead of the flywheel key.

    When time permits, visit my store at: http://stores.ebay.com/Evinrude-John...tc?refid=store

    I'd suggest that the carburetor be rechecked and adjusted as follows:

    (Carburetor Adjustment - Single S/S Adjustable Needle Valve)
    (J. Reeves)

    Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

    Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

    Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

    Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

    Note 2: If the engine should be a three (3) cylinder engine with three (3) carburetors, start the adjustment sequence with the center carburetor.

    When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

    When time permits, visit my eBay store at: http://stores.ebay.com/Evinrude-John...tc?refid=store

    There's a brass high speed jet located in the bottom center portion of the float chamber. Make sure that it's clean."
    We occasionally have questions. If you fail to answer, it may affect ours.

  3. #3
    Join Date
    Mar 2008
    Timmins, Ontario, Canada

    Default "Thanks Joe, I appreciate ever

    "Thanks Joe, I appreciate everything you guys do on this site. Wow that was a quick response. I'll get right to it.

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