Thermostat?

[swrupert83]

How important is the thermostat on the engine?

I just fired up my '85 85hp Force this weekend in the bucket, and noticed that the water took a few seconds before it began coming out the back and when it does its more of a spray than a stream. I pulled the cover off of where the t-stat is supposed to be and.... no t-stat. also, is the lack of back pressure that would be created by the t-stat the reason why its spraying instead of being a stream?

 

[ljc1957]

Re: Thermostat?

S83, does your engine have an actual "tell tale"? Some of these engines didn't have them and the "spray" you're talking about maybe normal. On my 66 Chrysler motor, there's an exhaust port below the cowling, just above the waterline. When running, it spits out a spray not a stream. It takes a couple of seconds for the water to travel from the pump to the exhaust outlet. If you haven't checked your impeller, it's probably a good idea. You should have a t/stat in that motor, they run better at their optimum temp. My engine runs at 130 degrees.

 

[swrupert83]

Re: Thermostat?

no tell tale, i wasn't sure if it was smoke or steam coming out with the water... but i could keep my hand in with out any pain. Any idea how to find the correct t-stat.

also any idea how to find a cheap clamp block mount, I only need the part that mounts to the transom, my 70's vintage one fell apart. All the local marine stores wont go below $190, for alittle block of steel or aluminum that is a rip off and I know they can't be paying more than $20 for it.

 

[SweeperForce]

Re: Thermostat?

It's been my understanding that the t-stat only keeps the motor running smoothly while cold, As the motor heats up, the t-stat opens to cool it. You can run it without a t-stat, it just may run rough until you reach normal operating temps(130-160). Your impeller may be spinning and pumping up water properly, but the water just comes out of the relief port until the t-stat opens. It may come out either in a spray or stream. If it never opens or is stuck shut, you'll overheat in a heartbeat. I assume the previous owner never put one in to eliminate the whole overheating issue caused by a thermostat. I replaced mine last year just to be on the safe side. T-stat and gasket for my local marine cost under 30 bucks. Hope this helps.

Tom

 

[jerryjerry05]

Re: Thermostat?

The thermo is needed to keep the motor at operating temp.It should be there.They can be found on this site.
The mist you see is from the pressure relief ports.NORMAL!!
Most of the water/exhaust goes out the snout.
It takes a few seconds for water to circulate to the thermo area.
Replace the impeller(just in case),do a compression test(just in case) and start changing the hoses cause Ethanol is messing with older hoses and causing problems.J

 

[maxpower_hd]

Re: Thermostat?

I also have a Chrylser outboard I am bringing back after 8 years of storage. I had a problem way back when where the overheat alarm didn't work and I lost a piston. That was fixed back then. What I want to do now is add a tell tale stream so I don't have to rely on the alarm. Does anyone know an easy way to do this? Mine is an 198? 90 horse. I think it's a 1983 but I would have to confirm.

I see what appear to be water lines that go to each piston water channel. My thought was to put in a tee on one of these and add a small line plumbed out the side of the lower housing so I could easily see it. I would use something as small as possible as not to rob too much water from the motor. I was also thinking it should be done at the highest point assuming that if water is reaching the top AND making it out the tell tale then water should be making it everywhere else.

Any thoughts?

 

[maxpower_hd]

Re: Thermostat?

You know....I'm not a rookie to forums although I am a rookie here. i should have checked the FAQ sticky first. I found what I needed I think. I will have to look at my model and see if I have the plug at the top of the head where I can add a fitting.

Sorry for the rookie mistake. I would still like to know if anyone has any other thoughts or ideas though. My goal is in flux right now. I'm either going to use this motor to repower a different boat or sell the motor to help fund a different boat. Either way I want it to be right.

Thanks again.

 

[wickware]

Re: Thermostat?

I like the tell tale on my 1970 35 HP Chrysler because it gives a solid stream from a glance vs the spray appearance in the rear. I feel I have noticed the spray in the rear looks closer to a solid flow at higher RPMs. jow