How important is the Thermostat?

[McGvr]

Hi All,
I have read several post that refer to the importance of the thermostat.

My 1987 30HP Evinrude did not have a thermostat installed when i bought it. I found out while working on it after it over heated, this was after I ran the motor through the mud (Lots Of mud) and destroyed the water pump. ( The motor ran great for 2 years before I found out it did not have one)
When I went to the boat shop to get parts (Including the Thermostat) they told me that unless I planned on using the motor outside of Florida, that I did not need it. He explained,the thermostat is there to bring the motor up to operating temperature and keep it from running cold, he said that's not a problem in Florida because the water is generally warm year round.

I'm now confused. Do I need it or not??

McG

 

[Chris1956]

Re: How important is the Thermostat?

Thermostats keep the cooling water between 140-180*. Will Florida water consistantly do that? I think not.

If you want the motor to run the best, use the thermostat. Make sure the waterpump in in good condition, as is the water passages.

 

[tashasdaddy]

Re: How important is the Thermostat?

the water can move too fast thru the power head, thus not allowing the water to absorb the heat, it can also cool it too much. it will cause fouling of your plugs, build up of carbon, which you just took care of. as said the thermostat starts to open at 140 * engine temp really should never get above 160*.

If you mechanic said that, when you need work done, find another certified mechanic.

believe me, if it was not needed, the bean counters would not have let them install it in the first place.

 

[McGvr]

Re: How important is the Thermostat?

Thanks guys,
I was kind of leaning that way. What kills me is that I was going to buy the thing. It cost them a sale.
I actually have started getting my parts from another dealer, the problem is that Bob's is about 4 miles from the house and the new place (Funtime) is about 40 miles (I have to go to Merritt Island). But I do get really good advice from them.

Well it looks like a trip to Merritt Island.

McG

 

[tashasdaddy]

Re: How important is the Thermostat?

most of my parts either come from iboats marine store, or here http://shop.evinrude.com/

my time is worth more than chasing parts.

 

[McGvr]

Re: How important is the Thermostat?

Do they have a good price on shipping?
I have found several places on-line for parts, the problem is the ones with the best prices have terrible shipping.
Ishopmarine, has great prices and huge selection BUT shipping.......Not so good.

I needed some gaskets and seals, the cost was about $12 the shipping was $19
and that was for UPS ground not overnight
I'll check Iboats, may save me a trip to MI

McG

 

[Chris1956]

Re: How important is the Thermostat?

McG, There are other sources for parts. Try ebasicpower.com as one example. You can do a google search on the part numbers and multiple sources will pop up. You will need to c/o the shipping costs manually.

 

[tashasdaddy]

Re: How important is the Thermostat?

iboats, and http://shop.evinrude.com/ have good shipping rates, and are fast. ishopmarine is high, and slow.

 

[npd4432]

Re: How important is the Thermostat?

I have ordered parts from here on several occasions and all times the shipping was fast, order was correct and the prices are good. Highly recommended.

 

[Silvertip]

Re: How important is the Thermostat?

Asking a parts counter person for engine advice is like asking a doctor's receptionist for medical help. Yes -- they know parts and can provide general advice. No -- they are not necessarily up to speed on engine technology and why things are the way they are! You very likely would have received a different response if you asked one of the technicians in the shop if the thermostat was necessary.

 

[metriccrescentwrench]

Re: How important is the Thermostat?

...the water can move too fast thru the power head, thus not allowing the water to absorb the heat...

This is one of those urban legends that's simply not so. (In a previous life I was a chemical engineer, and did a lot of work with heat transfer.) With heat exchange the more coolant flow you have the better, period. The only limiting factor is pumping efficiencies.

Sorry to nit-pick, just hoping to add a little bit of knowledge to a great forum.

 

[ezeke]

Re: How important is the Thermostat?

I think that Mr. Reeves' reasoning is a tad more scientific: http://forums.iboats.com/showpost.php?p=1797826&postcount=10

 

[McGvr]

Re: How important is the Thermostat?

This is one of those urban legends that's simply not so. (In a previous life I was a chemical engineer, and did a lot of work with heat transfer.) With heat exchange the more coolant flow you have the better, period. The only limiting factor is pumping efficiencies.

Sorry to nit-pick, just hoping to add a little bit of knowledge to a great forum.

I agree with that, which brings me back to TDs other point, without the thermostat the motor may run to cool.
I'm going with, installing a thermostat

 

[McGvr]

Re: How important is the Thermostat?

Great discussion guys!
Thanks for the help.

McG