9.9 Evinrude cooling problem

[william =robert1]

I have a 1975 9.9 evinrude(10524c). When the motor is running at idle or a little above, no water comes out of the exhaust hole and the motor heats up. If I go to about 3\4 throttle a little water comes out and the engine cools off rapidly. I have just changed the water pump impeller and everything else looks fine,and the pump plate was not scored. Should I be looking for a blockage or mabye a thermostat problem. Also what would be a normal operating tempature? Other than this cooling problem, she runs like a top. Any help, info or comments would be greatly appreciated.

 

[william =robert1]

Re: 9.9 Evinrude cooling problem

If any body can shed some insight on this problem I will be very greatful.

 

[ICEMAN]

Re: 9.9 Evinrude cooling problem

Hi, It's possible that the upper water tube grommet is restricting the water flow into the powerhead. I have come across this often in these older 9.9 motors. You would need to remove the powerhead and exhaust tube to get to it. Time consuming job for such a little part, but necessary sometimes. P.S. Have Patience, Some of us aren't online 24/7/365. Most topics get replied to, But not always within an hour.

 

[william =robert1]

Re: 9.9 Evinrude cooling problem

i removed the thermostat and ran the motor momentarily. Loads of water getting to the powerhead. I dont know what to check next.

 

[william =robert1]

Re: 9.9 Evinrude cooling problem

Any more ideas?

 

[NathanY]

Re: 9.9 Evinrude cooling problem

Does it overheat without the thermostat? Might be sticking until the motor gets real hot. Have you checked the impellor? Is the pump housing clean? Is the tube that goes from the pump housing to the power head clean? Are you running proper heat range plugs? <br /><br />Here are the things that I would do if it were my motor.<br /><br />Change the impellor even if it has been done.<br />Clean the pump housing real good<br />Pull the water pick up tube and clean it<br />Replace the thermostat<br />Power Flush water jackets<br /><br />That is all there is to a cooling system.

 

[william =robert1]

Re: 9.9 Evinrude cooling problem

thanks for your help, Im glad to have found this site. Looks like it does a good service to lots of people.<br /><br />Life is a game. Fishing is serious.

 

[GF]

Re: 9.9 Evinrude cooling problem

 

[Solittle]

Re: 9.9 Evinrude cooling problem

williamrobert1 - I have one of those little 75 9.9 workhorses. If the above suggestions do not fix the problem, take the head and exhaust covers off. Sometimes crud will build up in the water passages and restrict the water flow even if you have a new impeller & good thermostats. This is more prevelant in salt water motors. An easy job - get new gaskets if you do it.<br /><br />Howard

 

[Neil]

Re: 9.9 Evinrude cooling problem

WB1,<br /><br />I have an exact post. Mine is an Evinrude XP10.<br /><br />Similar problem. Steam out of tell tail I have replaced my pump and before I refitted I connected a hose pipe to the pump outlet pipe. I found a surge and then a trickle at the outlet pipe. I can pass water in both directions so I know the passageways are not blocked, but it does look restricted.<br /><br />The grommet was also suggested. It is strange though how I do get a large surge when I initially connect and then it slows. I suspect some pressure regulating somewhere. Next step is thermostat removal.<br /><br />NG

 

[Boatist]

Re: 9.9 Evinrude cooling problem

Williamrobert<br />First how hot does it get?? Should be able to hold finger on power head for 3 to 4 seconds, about 150 degrees.<br /><br />Was your motor doing same thing before you changed the impeller??<br /><br />Before you do anything I would suggest you start up your motor on the muff and let it warm up. Shut it down and at the water outlet at the back of the motor near the cover latch force water in this hole to back flush. I use a tapered sweeper hose attachment that works very well. You can also try forceing water in water outlet holes above the cavation plate but will have to plug all the holes on both sides.<br />After that I would try the motor on the muff again and see if find any difference. Next I would pull thermostat and put in a pan and make sure it opens at 140 degrees. While you have it out clean passages as much as can and flush out.<br /><br />If unit was not over heating before impeller was replaced then I would pull lower unit again and check a couple of things. First thing to check is where water tube goes in top of impeller housing there is a rubber Grommet with a couple of ears on it. Not uncommon for this grommet to catch on the water tube durning instalation and fold over plugging the water tube. If that is ok then I would pull the water pump impeller houseing and reinstall. Make sure the Plate below the water pump is put in correct. Worn side up and hole to front port side. Put some gasket sealler on both sides as pump sucking at this poing and a air leak can cause it not to suck up water. Next put on your impeller and key pin. Put impeller cup in impeller housing and again put some gasket sealer around base then slide housing over impeller while turinng clockwise. Two long screws go in the front and the short ones in the back. Make sure the seal and O ring on top of the impeller housing are installed and the O on end of drive shaft. When putting lower unit back on make sure water tube installed up in power head and bottom goes inside impeller grommmet, I put a little grease on it.<br />Good Luck and let us know what you find.

 

[DJ]

Re: 9.9 Evinrude cooling problem

williamrobert1,<br /><br />I think you answered your own question. If you get plenty of flow without the t-stat. That's the problem.

 

[Neil]

Re: 9.9 Evinrude cooling problem

Williamrobert1<br /><br />I agree it is the thermostat.<br /><br />I just lifted nine out and it was broken. My pressure surge was due to the seat being forced oout by water pressure and then shut down by the spring.<br /><br />That was the least of my problems. With the thermostat out I had little flow. I left the hose connected and watched sand pump out until it cleared.<br /><br />If you have water coming out of the housing you just need to replace the stat and seal.<br /><br />NG