85HP Johnson Javelin Water Heating Problem

[shynot]

My husband and I disassembled the lower end of our 1977 Johnson Javelin 85HP OB to replace the impeller. We did this because he noticed we weren't getting a good discharge from the pee hole and the engine was getting hot. We discovered the key way had lain over and disappeared somewhere! Otherwise everything looked ok. We replaced impeller and are still barely getting any water from pee hole, it is just bubbling up, not streaming out. We feel fairly confident the tubes are lining up - but how and the heck are you sure? Is there anything else we can check. Where does the water come in? What is behind that plate on the part of the motor that faces the back of the boat? Man, it was a long day, the lower end was heavy. We struggled, and thought we had done good . . .

 

[DJ]

Re: 85HP Johnson Javelin Water Heating Problem

The "telltale" is NOT always a good indicator. They frequently become clogged.<br /><br />Are you sure it is actually getting hot? You should be able to touch to top of each cylinder head, for a few seconds, with out getting burned. It should be about 140 degrees F.<br /><br />The water comes in the slots just above the gearcase "bullet".<br /><br />If the plate you are referring to is just below the lower cowl pan, it is just a cover for aesthetics.

 

[shynot]

Re: 85HP Johnson Javelin Water Heating Problem

Thank you DJ. I asked my husband about that plate, evidently I misunderstood him. He indicates it is a plate, under the engine cover, between the two cylinders, that is about 6"x8", where the water tube originates. He is wondering if that is a part of the water jacket. Is "telltale" the proper term? Or "signal hole", I've just been repeating what the guys at the marina said . . . I think we are going out again tomorrow and we'll test really how hot things are getting. I think the idea my husband had was to see if he could find a clog . . .

 

[emdsapmgr]

Re: 85HP Johnson Javelin Water Heating Problem

The 6" X 8" plate you refer to is the exhaust cover plate. The water telltale originates there. It is a water jacket/cover. If the water pump was replaced correctly, you should have proper cooling. If you still have cooling issues, you may want to open up the thermostat housing and replace both thermostats, check the pressure relief valves. This housing is located directly below the exhaust cover. The two large hoses to the heads come from that housing. When in there, make sure the two very small holes in the valve body are open or it will overheat.

 

[shynot]

Re: 85HP Johnson Javelin Water Heating Problem

Thank you emdsapmgr, we'll check that out. Thanks for the detailed info. I'll post our results later, hopefully, everything will be fine.