1983 25hp Johnson Water Circulation Problem

Paul Trahan · Dec 1, 2007

I just purchased a 25hp Johnson (w/ boat) and the engine runs great, but it does not circulate water through the pee hole. I replaced the impeller and installed a water pump kit, but it still does not work. I pushed water through the engine (by running a hose directly up into the intake, below the engine inside the exhaust housing), so I know the engine is clear. I blew through the copper water tube, and it is clear. I am stumped. I certainly would appreciate any help.

Paul Trahan · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

Let me add, I believe the boat has been setting up for about two years. I was surprised that the engine was so quick to fire up.

HighTrim · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

Remove the tell tale hose and clean it out. Also remove the "nipple" on the cowl and clean it out with a needle or weedeater line or the like. Spiders love to build nests in there, blocking water flow. If you remove the tell tale line and run the motor, will water now exit there? Let us know what you find. Good luck.

Paul Trahan · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

I don't think that is the problem because I shot water through the engine and water came out of the tell tale line (I assume this is the same as what I have always heard called the pee hole?) with pretty good force. Should I try what you suggested anyway?

HighTrim · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

ah no sorry then, i misunderstood. Was the water intake area clean of debris? When re installing lower unit, were you careful when lining up water line with the grommet on top of the impeller housing? I have seen that as a trouble area a few times. Are you running the boat on the water or in the driveway on muffs or in a barrel?

F_R · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

It's that time of year again, when we gotta ask everybody if they are running the motor in a bucket. Are you? The motor has to be deep enough to submerge the water pump before starting it. The pump is not self priming.

HighTrim · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

exactly my thoughts

Paul Trahan · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

HighTrim said:
ah no sorry then, i misunderstood. Was the water intake area clean of debris? When re installing lower unit, were you careful when lining up water line with the grommet on top of the impeller housing? I have seen that as a trouble area a few times. Are you running the boat on the water or in the driveway on muffs or in a barrel?

The water intake area is clean of debris. I was careful to make sure the copper tube landed in the grommet. I am running the boat in the driveway w/ muffs. Might this make a difference? Thanks for your help.

HighTrim · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

Let me get this right then. When the lower unit was down, you shot water up the water line and it exited as it should? But when the lu is installed, it does not pump any water? If so, I would double check the key for the impeller or the water line.

Paul Trahan · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

That is what I will do then. Tell me this, does it make a difference how you put the impeller in? I honestly can't remember how I put it in. I will check the book and make sure that I have the "clockwise" or "counterclockwise" thing right. But, to me, it seems like with that soft plastic it would just reverse direction with the rotation of the shaft.

HighTrim · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

with a brand new impeller, no it does not matter which way you drop it on the shaft. You do however need to rotate the driveshaft clockwise while lowering the impeller housing onto it. Add some oil to the fins of the impeller to ease the start up. You did remember the key for the impeller right?

Paul Trahan · Dec 1, 2007

Re: 1983 25hp Johnson Water Circulation Problem

I remembered the key, but I have only tried running it with muffs. I will take F_R's advice and try running it in a bucket. If that doesn't work, then I will drop the lower unit again, take it apart, check everything (again), and see. Thanks for the tips guys. I will let you know what I figure out (too late to fire up the engine tonight, I will wake the neighbors).

F_R · Dec 2, 2007

Re: 1983 25hp Johnson Water Circulation Problem

When on muffs, water should go through whether the pump is working or not, because it is being force-fed from the hose. However, if the impeller is not rotating it can't get past it. (back to the key). This is to say that you can't check water pump performance while running on muffs.

Paul Trahan · Dec 2, 2007

Re: 1983 25hp Johnson Water Circulation Problem

Is there anything other than the key that would keep the impellor from rotating?

Paul Trahan · Dec 2, 2007

Re: 1983 25hp Johnson Water Circulation Problem

Mission accomplished! Thanks for all your advice. I ran it in a trash can, and it started squirting water immediately. This is curious to me, because I replaced the water pump kit on my Johnson 28SPL, and I only tested it with muffs, which worked fine. At any rate, I am fired up about getting this boat out on the water. The temperature is going to be near 80 today here in Austin. It is a good day for it. Thanks again.

F_R · Dec 2, 2007

Re: 1983 25hp Johnson Water Circulation Problem

Well, let's back up a bit. Checking on the parts diagram for a 1983 25hp I see that that one still has the old style gearcase. Muffs don't work on that one. The water intake screen is on the leading edge of the exhaust outlet snout, below the anti-cavitation plate. Any water you squirt in those little holes in that side plate will just run out the intake screen just mentioned. No wonder it didn't work.

HighTrim · Dec 2, 2007

Re: 1983 25hp Johnson Water Circulation Problem

Glad you got it. Now Im jealous, here my boat is under 100 feet of snow

Paul Trahan · Dec 2, 2007

Re: 1983 25hp Johnson Water Circulation Problem

F_R said:
Well, let's back up a bit. Checking on the parts diagram for a 1983 25hp I see that that one still has the old style gearcase. Muffs don't work on that one. The water intake screen is on the leading edge of the exhaust outlet snout, below the anti-cavitation plate. Any water you squirt in those little holes in that side plate will just run out the intake screen just mentioned. No wonder it didn't work.

That explains it FR and makes perfect sense. I guess that means that I am going to have to use a bucket all the time, which is not a big deal. I have a small trash can that fits perfectly. Thanks again guys for all the help. This is my second boat purchase, both used. This last one (a 25hp Johnson on a 14' Sears Gamefisher) is for my mother for a Christmas present. She lives on the Trinity River. I can see how this might get addicting. It is a lot of fun.

1983 25hp Johnson Water Circulation Problem

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