Can I trash the thermostats?!

[dakk1]

Hey Guys,<br /><br />Can I trash the thermostats?! (Figuratively speaking.) 1985 Merc 150 Black Max. Here in Al. the water gets warm quick and I've been reading a recent thread about Mercs running on the hot side. I know some say that if motors didn't need 'em Merc. et al, would have left them out. Others make the point in hotter climes they're not necessary. Going to the coast tomorrow and plan on doing some trolling (read low speed not really good for Mercs.) What say you?

 

[one more cast]

Re: Can I trash the thermostats?!

Dakk,<br /> I'm no expert but your motor is designed to run a certain temp. say 160,180 degrees or whatever. by removing the thermostats you are lowering the temp. alot and I would think that would be not good.

 

[Walker]

Re: Can I trash the thermostats?!

Can't say about your Merc. but my johnson has a water cooled rectifier and without thermostats the water level in the block doesn't rech the rectifier.

 

[Joe Reeves]

Re: Can I trash the thermostats?!

Dakk.... (Thermostat Purpose)<br /><br />Many engines are considered high performance engines and demand a thermostat(s), but many smaller hp engines also require a thermostat for the following reason. The pistons actually distort/twist off round when running. The thermostat is required to keep the outer wall surrounding the steel cylinder, and the cylinder wall itself at a temperture to compensate for the distortion.<br /><br />With the thermostat removed, the difference in temperture between the inside the cylinder and the water jacket quickly reaches a point whereas (in effect) you have a oblong piston running up and down a round cylinder. Bottom line is without the thermostat, the piston and cylinder wall could be damaged in a short period of time.

 

[dakk1]

Re: Can I trash the thermostats?!

Thanks to one more cast, Walker, Joe Reeves.<br /><br />I didn't realize that outboards operated in such a narrow temperature range such that they needed to be that precise. I see and hear of so much going wrong with overheating really never considered problems caused by "underheating". I thought that since I would be trolling a lot this week and idleing and low speed seem to be associated with overheating, that pulling the t-stats might be the answer. So, scratch that idea.<br />Thanks Again!