As my name implies, I am no expert on water cooled two stroke motors, but I can turn a wrench. I have a 1984 8 HP Evinrude long shaft sailing Model # E8RLCRM that is over-heating . A brief history: This motor ran in brackish water in an earlier life, but is run only in a fresh water lake now (5+ years). Since mid-July, it began to steam from the exhaust relief, getting worse each time I took it out. The water pump indicator stream was normal, although the water temp. being discharged quite hot to the touch. I replaced the heavily encrusted thermostat, rodded out the cooling ports as best I could, and tried it again last night. Not only was it worse, the indicator was intermittent. Of course, once tied up safely in the slip, the WP indicator stream was running fine. I checked the thermostat housing and found the ports on both sides of the T-stat wet.<br /><br />I will change the water pump, but I am concerned there is a problem with something clogging the cooling ports. The skipper in the slip next to me suggested running the motor in a 5 gallon bucket of vinegar to clean the ports. Therein lies my questions: Has anyone heard of this before, is it safe? I'm concerned about compatibility of vinegar with seals, gaskets, etc. Also, if this is a good idea, should I run the vinegar through with the old water pump or the new one
what is the greater advantage/reduced risk if any? <br />One other point... this began not long after I mixed a batch 50:1 with Texaco Havoline TCW-III for the first time. I have used Evinrude and Pennzoil TCW-III in the past without problems, and didn't think about this until now. Is that a potential issue?<br /><br />Thanks in advance.
