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  1. #1
    Join Date
    Sep 2018
    Location
    NE Alabama
    Posts
    8

    Default 1994 OMC 50 hp cooling system questions

    This question may sound ridiculous to some but I'm puzzled and a little embarrassed.

    I just put a '94 Johnson 50 hp back into service after a 2+ year down time due to illness.

    I noted no tell tale stream when running on the muffs. It doesn't overheat but there is not a tell tale stream. I've checked the hose and find no obstructions from insects etc. The problem is I can't remember if the stream is dependent on the state of the thermostat or not. In other words does it "piss" on start-up or does it have to warm up first? I'm also wondering if I should be able to blow air through the tell tale hose back through the engine or not? I can not do so even with the water pump removed. As a precaution checked the water pump and out of an abundance of caution replaced it. I have yet to test but will in the morning. I just want to be "armed" with all the information I can gather before proceeding further if the water pump replacement doesn't solve the problem (if there is one).

    Also, for another reason, it was necessary to separate the two upper cowl sections and in the process the exhaust baffle grommet (between the lower cowl and the exhaust housing) cracked. Can it be safely run in that condition while I search for a replacement or figure out how to mend mine? Can you believe there is only one in stock world-wide! The guy that has it won't sell it and says he has turned down $180 for it.

    Any advice from you "ole hands" will be greatly appreciated.

  2. #2
    Join Date
    Sep 2010
    Posts
    24,219

    Default Re: 1994 OMC 50 hp cooling system questions

    Water should come out of the tell tale within seconds after the motor starts.-----Part # of this exhaust baffle grommet ?-------I think I have a few used ones laying around.

  3. #3
    Join Date
    Sep 2018
    Location
    NE Alabama
    Posts
    8

    Default Re: 1994 OMC 50 hp cooling system questions

    Quote Originally Posted by racerone View Post
    Water should come out of the tell tale within seconds after the motor starts.-----Part # of this exhaust baffle grommet ?-------I think I have a few used ones laying around.
    Man that would be terrific! The part number is 0334883. There is a visual of it at this link. https://www.crowleymarine.com/parts/16769.cfm

    It's been a while since I last changed a water pump. How difficult should the drive shaft be to turn after installing the new pump. It seems tight to me.

  4. #4
    Join Date
    Sep 2010
    Posts
    24,219

    Default Re: 1994 OMC 50 hp cooling system questions

    Yes it will be harder to turn.

  5. #5
    Join Date
    Sep 2018
    Location
    NE Alabama
    Posts
    8

    Default Re: 1994 OMC 50 hp cooling system questions

    What's your opinion on running the engine with a crack in the exhaust relief grommet until I can find a replacement?

  6. #6

    Default Re: 1994 OMC 50 hp cooling system questions

    Run with cowl off.Motor runs poorly on exhaust fumes.

  7. #7
    Join Date
    Sep 2018
    Location
    NE Alabama
    Posts
    8

    Default Re: 1994 OMC 50 hp cooling system questions

    Quote Originally Posted by Rwbutler View Post
    Run with cowl off.Motor runs poorly on exhaust fumes.
    I didn't make myself clear. My understanding is that the exhaust relief grommet vents the top of the exhaust housing which I believe is separate from the upper cowl area where the carbs, and thus the air intake to the engine is located. I think that my only concern is for exhaust and water/water vapor intrusion into that upper area.

    I just need confirmation of that.

  8. #8

    Default Re: 1994 OMC 50 hp cooling system questions

    I'm sorry,I do not know where you broke your grommet.key word exhaust.

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