1976 Johnson 9.9 Cooling problem

[Fish mojo]

I put in a new water pump kit. Prior to I was not getting any flow out the exhaust port at the bottom. After putting the kit in, still no flow. I ran it in a tub of water, deep enough cover the inlet ports, but still see the outlet. The engine runs good. I used an infra red thermometer to measure the block temp. I get about 210 degrees. I have the tubes aligned properly and the pin is in the slot for the impellor. Any thoughts? Is there a thermostat that could be stuck shut?

 

[Solittle]

Re: 1976 Johnson 9.9 Cooling problem

210 is way to hot for that motor and I would not run it until you find the problem. You have a blockage somewhere. I don't remember if that motor has a tstat but if it does that would be the place to start. You can pull the lower unit and duct tape a water hose to the pickup tube and turn the water on (low pressure at first) and see where the water is going. This is like backflushing a car motor. If that does not seem to provide answers, pull the head and look for blockages and check the rubber deflectors (I think the 9.9s have them). Do this with the hose still connected and run water through it. Check also for a buildup of crud in the water passages (more of a problem with salt water motors) and finally you can pull the exhaust cover to check for crud there (do this last as it is not uncommon for those bolts to break on older motors.

 

[OBJ]

Re: 1976 Johnson 9.9 Cooling problem

Hey fish mojo...welcome to the forum.<br /><br />Just want to add a alittle to solittles post.<br /><br />I noticed that in your original post you said that you had enough water to cover the intake ports. Just want to make sure that the water was ABOVE the mating line between the lower unit and midsection. These pumps don't draft water. They have to be IN the water to work. So make sure the water is well above the pump.<br /><br />Keep us posted.

 

[seahorse5]

Re: 1976 Johnson 9.9 Cooling problem

If you still don't have water flow when you submerge the gearcase to the "split-line", then you may have a plugged up thermostat or quite possibly a melted and distorted water tube grommet under the powerhead. In severe overheat cases, it melts and blocks off the water flow to the powerhead. You have to remove the gearcase and the powerhead to replace the grommet.

 

[Fish mojo]

Re: 1976 Johnson 9.9 Cooling problem

I guess I need a shop manual. Is Seloc or Clymers better? Where is the thermostat? Any tips on pulling the powerhead?<br />Thanks

 

[8up]

Re: 1976 Johnson 9.9 Cooling problem

I have a Clymer manual for my 85' 140hp Evinrude. I'm not that impressed with it. If I had to do it over again I would flip for the factory service manual.<br /><br />Good Luck

 

[Solittle]

Re: 1976 Johnson 9.9 Cooling problem

Fish - Do yourself a big favor & get the OMC shop & parts manuals.

 

[DJ]

Re: 1976 Johnson 9.9 Cooling problem

Fish,<br /><br />You can get reprints of original OEM manuals-here:<br /><br /> http://ww3.kencook.com/evinrudejohnsonmanuals/

 

[Fish mojo]

Re: 1976 Johnson 9.9 Cooling problem

OK, heres an update.<br />I removed the water jacket cover and t'stat.<br />Then hooked up a hose to the water tube. Flushed some gunk clear. New t'stat and gasket and hooked it all up. Runs much cooler (135). Vapor and water droplets comes out the telltale.<br />However, exhaust smoke comes out the water outlet and some water leaks out around where the shift rod is exposed thru the housing.<br />We are better off, but is the head gasket leaking causing exhust gas to leave thru the water outlet?<br />ps, thanks for all the support. You guys rock!

 

[OBJ]

Re: 1976 Johnson 9.9 Cooling problem

Fish...the exhaust coming from the exhaust relief ports is normal along with the water droplets. If your hooked up to flushetts (ears) the water issuing from around the shift rod is normal. You got pressure in around there and will come out where ever there is an opening. 135 sounds good for temp at idle.

 

[tigermuskie]

Re: 1976 Johnson 9.9 Cooling problem

I have the exact same issue with the 9.9 I bought this weekend! How did yours end up?

Thanks in advance.

JOn

 

[tigermuskie]

No Overboard Water Indicator for the First 3 Years ?

No Overboard Water Indicator for the First 3 Years ?

No Overboard Water Indicator for the First 3 Years : The water simply was pumped thru the motor, then was exhausted out the bottom of the powerhead into a split section in the exhaust housing. There is a baffle that is only open on the bottom, slightly below the one 3/8" hole on the outer rear of the housing. This system was common to all the earlier OMC engines prior to these years & was carried over into this series of motors thru 1976. With this older system it could be hard to really tell whether your water pump was really working or not if you are used to the newer "pee hole". The only way to tell if the water pump is working is while the motor is running on a boat, place your hand behind this hole. It should get wet by the misty water that should blubber out along with some exhaust. If you are not certain, if the motor runs & the block does not get so hot that you can not hold your hand on it, the water pump is bad & needs replaced.

http://www.wisnersinc.com/Fishing Info/Johnson 9.9_15.htm

 

[tigermuskie]

Water Tube Test? (76' Johnson 9.9 Cooling Issues.)

Water Tube Test? (76' Johnson 9.9 Cooling Issues.)

Should I be able to blow into the waterpump copper tube to the motor with ease? Does the thermostat seal it off? I tried to blow clear and it blows very hard! But some air/water does go in?

Jon