To pull the thermostat or not?

4Winns22

Member
Joined
Oct 30, 2006
RO Number
24082
Messages
15
I winterized my 90' Four Winns with a 4.3 litre OMC Cobra yesterday. Only my second season with this boat so it was my first go around in winterizing this engine (a boat mechanic friend did for beer my first season).

I did all the usuals in order: warmed the engine up on muffs; changed oil and filter; changed outdrive lube; and fogged the carbs. Now, what I consider the most important part of the process: drained both risers and both sides of the block. Then I backfilled the four hoses going to the thermostat housing without pulling the thermostat out. The whole process consumed a total of 3 gallons. I've gotten a 50/50 opinion in my research about whether you should take out the thermostat or not when you pour A/F into the motor. Which practice do you adhere to? I would be interested to know since I'd like to (and my engine too) sleep well this winter. Thanks in advance for your input.
 
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