1986 V4 Johnson Thermostat stuck open

[vintage_car]

with my IR thermometer and running the engine with muffs on, the cyl are only showing 95 degrees after about 5-7 minutes of run time. I believe the thermostats are stuck open. No alarms going on. I don't see a printed replacement procedure in the manual I downloaded.
did some searching and some say pull power block, others have mentione removing exhaust panel and gaining access that way. the latter sounds much easier for someone who has not done this before. This leads me to the question, can I do this? I do have mechanical skills, but never worked on boat engines- only car engines. Does anyone have something printed that would show the latter process of removing those panels and where the thermostats are located?

 

[AEROCOOK]

Re: 1986 V4 Johnson Thermostat stuck open

What model number / HP?

 

[vintage_car]

Re: 1986 V4 Johnson Thermostat stuck open

What model number / HP?

guess that is important...duh! 110HP J110TLCDC

 

[emdsapmgr]

Re: 1986 V4 Johnson Thermostat stuck open

It sounds like your diagnosis is solid. Either the stat is stuck open, it is missing completely, or the nylon pressure relief valve is not closing properly at idle. You have a bubble back engine, and pulling that stat housing on that model is really a bear. A skinned knuckle job for sure. You can loosen the lower cowling to increase your finger wiggle room, but on that later model, it won't help much. Still it's better than nothing. You are still probably better off not pulling the powerhead-just the stat housing. A 1/4" drive socket set with a swivel connecter is the right set of tools. Best to run that engine with thermostats. I think the flat rate on pulling the powerhead is 3 hours, and you should be able to do the stat housing in less time.

 

[vintage_car]

Re: 1986 V4 Johnson Thermostat stuck open

Running with the stats open, since I did that this weekend not knowing there was this issue would that cause damage?

I actually found the issue because the vro sensor was hooked up but I mix my oil. The alarm for low oil sounded as I was on the lake (I jumped outta my skin!) so when I got home I disconnected and was testing the overheat sensor just to make sure it worked, which lead to the curiosity of how hot the engine was running... Not that any of that story really mattered, ha!