1990 Evinrude 200 hp Big bore Looper

[RetNav]

In the final stages at the shop rebuilding one of my motors and the mechanic wants to take the thermostats out and leave them out. He says we are in south Georgia and doesn't need them. Sometimes it gets real cold here too. Seems to me like if they weren't needed wouldn't have been designed with them in. Looking for opinions/reccomendations.

 

[93bronco]

Re: 1990 Evinrude 200 hp Big bore Looper

i wouldnt do it, they are there for a reason.<br />but then if he does it will he warranty it from a future ph failure due to piston seizing , broken rings from excess carbon or cylinder scoring?

 

[rickdb1boat]

Re: 1990 Evinrude 200 hp Big bore Looper

Agree with 2K BOAT. Make sure they put new ones back in. They are there to make sure the engine comes up to proper operating temp. Like you said, they are there for a reason! I would have to ask the Mechanic what his logic is as to why he would want to leave them out, other than you live in the south. Huumm!

 

[Joe Reeves]

Re: 1990 Evinrude 200 hp Big bore Looper

RetNav.... I try not to ever criticize a fellow mechanic, however your mechanic's suggestion about the thermostats does raise some questions.<br /><br />(Thermostat Purpose)<br />Many engines are considered high performance engines and demand a thermostat(s), and 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.

 

[RetNav]

Re: 1990 Evinrude 200 hp Big bore Looper

Hey guys, I really appreciate the quick response. I know that running a car without thermostats can cause overheating if stuck in traffic, etc... and figured the same of an OB. On these rudes it looks to be a simple fix as the t'stat is located at top (I think) of head and the bolts won't be hard to remove as the mech had to take them off to remove the tstats. I will get new and replace myself. Thanks again!