Johnson 1985-120hp V-4....water pressure

[Boseefus]

Big Howdy to all from a new member..I have a 1985 120 V-4 Johnson that has very little water pressure coming from pee-hole-water coming out, but no force to it-just gravity. I have hooked up a water pressure guage but it does not register. I change the water pump impeller every year and have changed thermostats and springs twice in the last 2 years but it has not helped. Overheat buzzer comes on and I shut it down, I feel the heads but they are really hot, and the peewater is just good and warm not hot. Any ideas? Thanks in advance!

 

[DJ]

Re: Johnson 1985-120hp V-4....water pressure

You've got a restriction someplace. Were any of your impellers destroyed (in pieces)?<br /><br />If so, there may be some parts of them floating around in the engine.<br /><br />Also, It's time to pull the thermostats and check them out again.<br /><br />Can you relate the symptoms you see now to a service interval?

 

[petryshyn]

Re: Johnson 1985-120hp V-4....water pressure

Hi Boseefus<br /><br />I think djohns is right. You have a restriction between the pump outlet and exhaust cover inlet, or a leak.<br /><br />>is it possible that the tube seal is missing out of the water pump housing?<br />>how did the impellors look when you've changed them? were any busted up, pieces missing?<br />>is it possible that the relief valves are not installed properly?<br /><br />If the above were OK, I'd pull the exhaust covers and leg. I'd blow with shop air from the exhaust cover water inlet and see if you have a free passage to the leg water tube.<br /><br />There are several passages throughout the engine and middle section that could house a restriction or provide a large bypass. I would check the easiest first.<br /><br />>check valve assembly<br />>seal in top of waterpump outlet<br />>remove exhaust cover and leg, and blow from exhaust inlet to water tube. If a restriction is noted (poor volume coming out the water tube) you could try using a pressure washer (car wash wand) to blow out obstructing pieces. (gonna require new exhaust cover gaskets)<br /><br />This is just my opinion, others may have better!!<br />Good luck

 

[Boseefus]

Re: Johnson 1985-120hp V-4....water pressure

Thanks for the infomation guys. Impellors look okay, heads are not really hot, I will pull it apart to check it out and use forced air to see what the restrictions are. Thanks alot once again. Sure am glad I found this forum. Thanks.

 

[petryshyn]

Re: Johnson 1985-120hp V-4....water pressure

Boseefus:<br />If the heads AREN'T hot, then I'd be looking at the relief valves first. They determine water pressure. They don't affect flow, so cooling isn't affected. Check them first. You steered me down a different path when you said the heads were hot....<br /><br />Good Luck!!

 

[Boseefus]

Re: Johnson 1985-120hp V-4....water pressure

Thanks again Schematic for replying to my post. On my original post, I left out the word "not hot" about the heads. Sorry about the incomplete post. I will check out the relief valves. Thanks, Boseefus

 

[Digdug]

Re: Johnson 1985-120hp V-4....water pressure

Hey Boseefus, I have a 1994 Evinrude 120hp and I have no pressure at the pee hole but engine seems to be cooling fine. My pressure guage reads 5-8 psi at idle and 25-30 psi at WOT. I have checked thermostats and water pump and everthing seems to be working fine. I have often wondered why no pressure out the pee hole. The pee-hole opening on my engine is about 7/16 diameter but hose to pee-hole is very small diameter...this may be the reason water does not shoot out.

 

[Boseefus]

Re: Johnson 1985-120hp V-4....water pressure

Thanks for all the replies everyone...Just waiting for warm weather here in NE to check to work on the motor..