Whaler Central - Boston Whaler Boat Information and Photos

Posted by gerobertson1 on 03/02/14 - 7:45 PM

Good evening folks. I have to tackle changing my thermostats on my 1980 Johnson 115. Does anyone have advice on how to tackle this job. I have read how they are a real pain to access, but I am hoping that someone on this forum has a sneaky little trick, or a special tool to use.

Thanks for the help.

1972 Katama 16'7

Posted by chiburis4 on 03/03/14 - 5:56 AM

If it's the same setup as my 1992 OMC 90HP V4 it's really not that bad. It's just a little tight getting the wrench in there to back off the three bolts because of the lower cover. Maybe cut down a wrench just for this job. I've done it a couple of times because the saltwater really eats them up.
Good Luck.

Posted by Weatherly on 03/10/14 - 6:19 AM

I have replaced thermostats on several of my V-4 90 degrees OMC outboards. Removal is easier than installation of the new t-stats. I use zip-ties to hold the complete t-stat assembly together as I bolt the unit back into place. You can cut and remove the zip ties after you have seated sufficiently the assembly to the block.

Replace the thermostats, gaskets, and grommets all at once. Make sure the white plastic pressure relief valves are free. The torque on the 1/4-20 bolts is 5-7 ft. lbs. File a very small notch in each white valve to help drain the thermostat housing and to bleed the air quickly when starting up the motor.

I saw an Evinrude 112 SPL with three bored out holes in the rear aluminium housing, that allowed for direct access with a socket wrench to the three thermostat housing bolts. The local fisherman that owned the motor kept a piece of black duct tape over the bored holes.

Posted by gerobertson1 on 04/17/14 - 6:00 PM

I knocked out the job tonight. Not as bad as I was expecting, but still a bit tedious. Glad I took the time to do it though. As I expected, one of the stats was stuck open. Hopefully this weekend I can take a test run on the bay.

Thanks for all the advice.

Posted by Whalerbob on 05/29/14 - 11:09 AM

A friend of mine suggested only using gasket sealer on one side of the gasket so the housing can be opened for inspection / cleaning without damaging the gasket. That's the way I did it last time and haven't noticed any leakage so my question is do you guys use gasket sealer, install them dry, or 50/50?