Johnson 5hp NO WATER PUMPING!

[ChrisCKL]

Hi all. I have a 1999 Johnson 5HP and the problem is there is no water coming out the pee-hole. This is what i did: When I changed the impeller with the vanes going the right way there was no water pumping still. So i thought i might have made a mistake and so I switched the vanes the other way (the wrong way). Still did not work so I finally put it in the right way (turning the shaft in a clockwise direction and lowering the housing). When i first started the engine after the new impeller the water ran fine in good amounts but then it died away and only hot air came out. I have heard of a thermostat, which can causes these problems aswell. I do not know where it is. Am i able to change it? and if so where abouts is it? I do not have a manual so please just guide me with a few words of your expertise. Do i ahve to buy a new thermostat or can i just fix the current one? what does the thermostat look like? please help me. I will get a manual when i have the time but i really need to fix this engine fast. Thanks in advance

 

[seahorse5]

Re: Johnson 5hp NO WATER PUMPING!

The service manual is avialable as part number 787027.<br /><br />That motor has a rectangular grommet that seals the top end of the water tube, where it makes a 90 degree bend underneath the powerhead. You may have to remove the powerhead and inspect the tube and grommet. Also in that area, salt, sand, and mud can build up restricting the flow of cooling water. There is no thermostat on a 5hp Johnson for '99. It would be a good idea to replace the head gasket whenever a motor overheats badly.

 

[ChrisCKL]

Re: Johnson 5hp NO WATER PUMPING!

I also feel that the problem was a build up in the water system. I have tried flushing it out by water in the lower unit (through the copper tube) and i saw only a trickle of water coming out at the pee-hole. This means there is a blockage? So seahorse are you saying i have to remove the powerhead? Is the powerhead the big engine block? The one where all the burning takes place? What is the powerhead? What is the grommet and gasket? Is there a difference? <br />sorry im such a newbie and thanks for your help so far

 

[oldboat1]

Re: Johnson 5hp NO WATER PUMPING!

Unless the engine is overheating and/or no water is coming out of the exhaust port, the tell-tale is probably plugged. If you can hold your hand on top of the cylinder head for a few seconds without burning yourself (in other words, unless it's too hot to touch), the engine is getting water through the water passages. If you determine the engine is not overheating, try inserting a fine wire into the tell-tale opening, or forcing air or water up there to clear the blockage.<br /><br />If the engine is overheating, there is probably a blockage in the water passage. To clear it, you may need to remove the cylinder head and the exhaust port cover and clean out the passages.

 

[Solittle]

Re: Johnson 5hp NO WATER PUMPING!

Chris - That is a good motor and I would hate to see you do damage to it due to your lack of knowledge or experience. We all started somewhere so please don't take offense.<br /><br />My suggestion to you is to have a marine mechanic fix it. You stated "Is the powerhead the big engine block? The one where all the burning takes place? What is the powerhead? What is the grommet and gasket? Is there a difference?" That tells me that you are starting at the very beginning learning about these motors. Buy a shop manual and read up on the basics. Then for the next repair or maintenance try it yourself using the manual.