74 johnson 15hp water problem

[mjc707]

I just bought a Johnson 15hp motor. It runs great but no water coming out of pee hole. I checked the water pump and all seems good. I will replace soon to be on safe side. I put a hose on the tube that goes from the pump up to the powerhead and blew into it and if I blow as hard as I can I can hear very little air. Is something clogged? Is it possible the t-stat bad or is there something else I should be looking for. Any help is appreciated. Thanks

 

[tashasdaddy]

Re: 74 johnson 15hp water problem

did the 74 have a tale tell hose? thought it still used the exhaust relief ports. if it has a hose, run some weed eater line up the hose, or disconnect it and clean it out. critters like to live in there.

 

[mjc707]

Re: 74 johnson 15hp water problem

I don't know what a tell tale is sorry

 

[iwombat]

Re: 74 johnson 15hp water problem

The '74 does not have a "pee hole" (tell tale). It uses the exhaust relief port and it will only spit a little after the t-stat has opened up.

 

[mjc707]

Re: 74 johnson 15hp water problem

Ok that tells you what I know. So how can you tell if you have good water circulation? Thanks

 

[iwombat]

Re: 74 johnson 15hp water problem

Unless the guy you just bought it from can produce documentation of a water pump change in the last two years, just replace the thing. After replacement, if you can see water spitting out of the exhaust relief port (just under the powerhead in the back), then you're good to go.

 

[mjc707]

Re: 74 johnson 15hp water problem

There is water spitting out just like you said. but I was told by the guy at the marina that it should be a solid stream. I guess I wasted a couple of hours taking it apart again for no reason. I appreciate the help and quick response. Thanks

 

[Rick.]

Re: 74 johnson 15hp water problem

mjc707: No time wasted, your just learning about your motor. Please heed Iwombats advice. Replace the impeller if your not certain of it's age. A twenty dollar item can cost you a motor. When the motor has been running and up to temp. you should be able to hold your hand on top of the head for a three count. Then you know it's cooling satisfactory. Best of luck with it. They are good motors. Rick.

 

[iwombat]

Re: 74 johnson 15hp water problem

You should still just replace it if you haven't already. Over 3 years old and you never know when they'll self-destruct.

 

[mjc707]

Re: 74 johnson 15hp water problem

replacing it is definately the plan I just wanted to make sure everything else seems good so I could get a list going and hopefully not make to many trips to the marina. I appreciate the info and help. Thanks again

 

[Mas]

Re: 74 johnson 15hp water problem

I know that a tell-tale does not verify cooling, but it does at least tell you if the pump is working at least somewhat. Monitor the temp often by checking with your hand so you can learn to be "one with your motor" by recognizing subtle changes.

MAS

 

[samo_ott]

Re: 74 johnson 15hp water problem

Be one with your motor? Hmmm... It sounds lonely where you are!

 

[Rick.]

Re: 74 johnson 15hp water problem

mjc707: Have a look at this link. This Mr. Wiesner has written several articles on the 9.9 and 15 OMC's. I think you will learn a lot by reading it. I know I did. Rick.

http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm