86 johnson 15hp water pump not pumping water

[guyute1500]

Hi guys, last year I bought a 14' seafarer with this motor and did a lot of fishing with trolling motor and never used the johnson. The boat had been sitting for a few years and I was told the carb had been worked on and it should run. Was planning on having someone go over it but it never happened. It's almost fishing season here in Pa and decided to take a look myself. First thing I noticed, besides the throttle being almost unturnable, was that there was no fuel pump. Ordered a new one, some new lines, and a couple plugs. Lubed up throttle handle and installed new stuff, put her in a 55 gallon drum. She started right up! Unfortunately I didn't get any water out of the pee hole. Blew the hole out,took the hose off and blew through it. Everything seemed good there so I ordered a new pump, had to be done anyway. The old impeller was toast, maybe one fin left. I tried to blow everything out and didn't see plastic anywhere. Installed new pump and still no water. Impeller key didn't stay so redid and tried again still no water. Decided to do the drill test and the water pump is not pumping anything. Could it be as simple as bad water pump? Any ideas?

 

[PGRChaplain]

If the Impeller is good it should Pump Some Water. I look for obstruction in the Water Passages. Have you run it with Ear Muffs on it?

 

[RaisedByWolves]

If the Impeller is good it should Pump Some Water. I look for obstruction in the Water Passages. Have you run it with Ear Muffs on it?

Yup, now you have to find the rest of the old impeller.

Using the drill, are you sure you’re turning it the right way. If not, put another new impeller in it or that one will shred too.

 

[Pappy]

Basics............ Start with the basics.
When you put the engine in the drum the water pump has to be covered with water. These pumps are not self priming unless covered by water.
Raise your static water line in the drum until it is completely past the parting line of the gearcase to the exhaust housing plus bring it up to the lower mount clamshells on either side of the exhaust housing. In other words as deep as the engine would be sitting if the boat were in the water. This is by far the most common reason a pump will not pump.
Two.....put a water hose on the pick up tube in the exhaust housing and see if the line is clear.
Three.....if the original pump was "toast" the engine may have been overheated to the point that the water tube grommets at the top of the water tube(s) are melted and closing off the water supply or severely limiting the supply to the powerhead. This may need to be checked. I have wriitten about this before and it is common to this series of engine. Also added photos of the grommets
Four.....Just because you get some water out of the overboard indicator this will not indicate whether these grommets are melted or not. The restriction is at WOT where you need it the most. I would run additional oil in the fuel until you are done diagnosing the lack of water.
Five.....if you are running it on the earmuffs that are squared off these muffs are notorious for not supplying water to the enigne. Get the round ones and make sure they are tight against the gearcase.

 

[guyute1500]

Thanks for the help guys. I never did find any of the old impeller plastic but i blew air through everything and it seemed clear. I thought i had the water high enough but i guess i was just under where lower leg and top unit join. I put it all back together and added a little more water to the drum. Still no water, so I shut it down. Came home from work just now and started the motor to run gas out so i could take the lower unit off again and viola! Nice, steady stream immediately! I know that's just an indicator but wonderful to see. Is there anything I should be looking for other than overheating, that will tell me if the grommets or anything else isn't right? I do have round muffs and can try it that way if it would make a difference. I'll take Pappy's advice and run a little more oil in the mix for the time being but I think I didn't have the water high enough even though I was aware of that from other posts, just seemed really high but that is where the water pump sits. Hopefully I can just change out the lube in the gearcase and take her out for the PA trout opener Saturday. Thanks again.

 

[Pappy]

Thanks for the help guys. I never did find any of the old impeller plastic but i blew air through everything and it seemed clear. I thought i had the water high enough but i guess i was just under where lower leg and top unit join. I put it all back together and added a little more water to the drum. Still no water, so I shut it down. Came home from work just now and started the motor to run gas out so i could take the lower unit off again and viola! Nice, steady stream immediately! I know that's just an indicator but wonderful to see. Is there anything I should be looking for other than overheating, that will tell me if the grommets or anything else isn't right? I do have round muffs and can try it that way if it would make a difference. I'll take Pappy's advice and run a little more oil in the mix for the time being but I think I didn't have the water high enough even though I was aware of that from other posts, just seemed really high but that is where the water pump sits. Hopefully I can just change out the lube in the gearcase and take her out for the PA trout opener Saturday. Thanks again.

 

[Pappy]

Yes, it is just an indicator. Your engine will not give you any indication of an overheat by the way. It has no buzzer or any means to let the operator know.
If your engine went through a complete disintegration of a water pump impeller it was overheated pretty badly. if the engine were mine I would have the powerhead off the midsection after ordering new grommets and a base gasket.....and replace the fuel lines while the powerhead is off as well.
Up to you whether you heed this advice or try and justify and ignore it. Not meant in a mean spirited way I have just seen too many go this route.