Possible thermostat issue??

**newbe2** · 06-08-2016, 07:31 PM

Hey guys, I picked up a used boat ( 1981 skeeter with 75 horse Johnson) a couple years ago. It had been stored it's entire life in a heated garage and properly winterized yearly. I even have recieps to show work through the years. I purchased from a gentleman's widow. Boat had sat for a few years his son said, so first thing I did was have a mechanic check it out when I bought it. New impeller and so forth. Flash forward a year later ( last fall) and it shut down on me for being over temperature. I basically let her set over the winter and just started digging into it last week. I replaced waterpump housing, impeller. I noticed when I fired it up that it had water coming around motor cover so I removed to find water coming straight out of water jacket on side of the motor . It looked like it had happened some time before and instead of replacing the plastic fitting, the person just glued it back into the motor. I used the original size tap drill to clean out the hole. The threads were still good so I picked up a brass fitting at hardware store to use in place of the original plastic one. I put the muffs on and started her up. I once again had water Coming from the tale tale hole. I let her run for about five minutes and the stream of water coming from tale tale began to get smaller and smaller. The engine started to get noticeably hotter so I shut her down. All the information I have found online points to cooling issues primarily coming from a blockage, or a bad impeller. I just replaced impeller, and if I had water coming through tale tale for first few minutes that makes me think I don't have a blockage? My next thought was the thermostat, but have read that when they fail, they fail in the open position. I believe my next step will be to just replace the thermostat, but I'm curious to the opinions of others. Thank you in advance to anyone that takes the time to read my long winded story!

**Cray** · 06-08-2016, 09:43 PM

Water not coming out of tattletale hole should have nothing to do with thermostate. On that motor if I'm not mistaken you should have 2 holes on back side of center section, should be water mist coming out of there when thermostat opens. First pull that fitting out and check it for any trash, blow out the hose that goes to it, take a small wire or something that will fit and make sure the pee hole is clean even though you had water flowing. Then with all that off and the cowl off turn on the water and see if your getting any flow out of it, then crank motor and see what happens. If no water flow, pull lower back off and you need to blow air back through that fitting hole to try and blow out any trash. Then recheck water pump was installed in right direction, and that water tube is clear and double check that upper seal on pipe is good. When reinstalling make sure it is going in place and seated properly.

Plus you can check thermostat by just removing it and run motor without it.

**newbe2** · 06-10-2016, 06:55 AM

Thank you Sir! I'll definitely try what you have mentioned this weekend. I appreciate your response.

**dfar** · 06-13-2016, 04:24 PM

If you did not have the water hose turned on high enough when the thermostat opened it would cause the condition you described.
Try turning the hose up before you do any thing else. Was the old water pump bad?

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