1991 johnson 140hp not warming up?

[boating maniac]

During the summer time the temp gauge goes up to the middle and stays there. But during the winter time when the water is cold it pretty much stays at the bottom. Now the temperature of the water in the lake is about 70 degrees and it stays just a little bit off the bottom. My question is is that temp gauge the temperature of the engine or the temp of the water going through the engine? The engine runs just fine and everything.

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

I forgot for the model number was since I threw away the paper I hade it written down on. But I think it is a VJ140LEID

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

Anyone have any ideas as to why the temp gauge doesn't move when the water is cold?

 

[boobie]

Re: 1991 johnson 140hp not warming up?

The temp gauage may not be accurate. Best way to measure temp is to check on top of the block with an infared red temp gun.

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

what causes it to be not accurate? It's one of those idiot gauges that's for sure. What temp should I be seeing? I'll check it with my heat gun. I'll probably only be able to do idle speed unless I can get someone to go with me on the boat.

 

[Faztbullet]

Re: 1991 johnson 140hp not warming up?

That engine has the water control valve and it should show warm till the throttle is opened. I would check it for proper operation and the hose routing off t-stat/poppets.

 

[boobie]

Re: 1991 johnson 140hp not warming up?

After it is warmed up properly the temps on top of the block just before the heads should read 140* +/- 15*. If not you have something wrong with your thermostats. The mtr should run the same temp weither the water is hot or cold.

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

Alright well I took the boat out today and went out for a couple hours. I came back to the dock and put my infrared thermometer to the powerhead right before the cylinder heads and both sides showed about 95 degrees. This was with the engine idling at the dock. I know this engine has 2 thermostats. What's the chances of both of them staying fully open?

 

[boobie]

Re: 1991 johnson 140hp not warming up?

First off check the thermos and then look at post # 6 again. This mtr has a goofey temp control system on it. You may also want to check shop.evinrude.com and look at the parts diagrams.

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

Are the thermostats at the top of each head with the hoses routed to each other and there are 4 bolts holding them on? Is this something I can easily remove and inspect without having a bunch of parts fly out that I won't be able to put back on?

 

[Solittle]

Re: 1991 johnson 140hp not warming up?

I be bettin that someone pulled the t-stats & did not put them back in.

 

[boobie]

Re: 1991 johnson 140hp not warming up?

Did you check the parts diagrams I told you about????? If you do you will see water pressure holds the thermos on their seats when the mtr is idleing.

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

I didn't see anything about the thermostats on the parts list on that website

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

Ok I found it. This is a diagram for an evinrude though. I have a johnson. Are they both the same engines? Don't they have parts diagrams for johnsons?
I looked at the cylinder and crankcase section. Looks like number 37 is the control valve assembly you guys mentioned for 82 dollars and number 94 is the thermostat assembly for about 32 dollars each. Does the assembly mean it comes with all the gaskets and everything or is that just the thermostate itself?

 

[boobie]

Re: 1991 johnson 140hp not warming up?

Dumb question. Did you ever check to see if the thermostats are in it?

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

Nope never did. This thing acts like it doesn't have them in doesn't it? I've heard of people removing them. I suppose that's fine during the summer but what about when the water gets cold? It's not good to run an engine cold all the time.

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

I found a diagram that shows the thermostat for the johnson. They
are only 22 bucks each. They are 140 degree t-stats. It doesn't look like there is anything more than just the thermostats themselves. Is that all I need to buy if in fact I find they aren't in there? Or are there gaskets that I need to replace too? An outboard motor should get up to temperature regardless of the water temperature right? Just like a car.

 

[Faztbullet]

Re: 1991 johnson 140hp not warming up?

n outboard motor should get up to temperature regardless of the water temperature right?

Yep... I know the early V-6 loopers with this water valve design will run hot if t-stats are removed, never tried it on on V-4 but would guess it would do the same.. The t-stat/poppet on that motor should unscrew and you can just replace the vernatherm or t-stat inside it depending which style it has.

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

Running hot isn't the problem. I remember in the summer time when the water temp was 90 degrees it would go just a little past the midway mark on the gauge when you were running it at full throttle. But it would go back to being normal if you slowed down. That was with a full tank of fuel, fishing poles, ice chest full, and another buddy on the boat. Then once the weather got cooler the engine would stay cold. I'm gonna pull the thermostats out if they are in their today. How do I tell if it's open or closed?

 

[boating maniac]

Re: 1991 johnson 140hp not warming up?

Ok well I took out one of the thermostats. Here is what it looks like. How do you tell if it's opened or closed?