Joe your response led to more questions

" Joe, thanks for helping me w

" Joe, thanks for helping me with this little motor- the 70 model 9.5 johnson. I am having trouble finding a new thermostat for it, so, I thought maybe I will start by checking/testing the old one. Is there a way to test to see if it is working properly? I cranked the engine in a barrel and it smelled hot, so I shut it down and noticed a "bubbling" of material (like Permatex) around one edge of the thermostat housing cover (I had the cover off the motor). I also never saw any water coming from the top rear area of the engine. How can I make sure water is even going to the thermostat, and then out again?

Also, without a gauge or alarm, how would I know if this engine is overheating and what will it do if it overheats? Is there a risk of damage if the thermostat is left out and the motor is run? I sure don't want to damage the motor. I know this is a lot of questions, and I really appreciate your time and expertise. I won't be able to do anything to it until Saturday, but I will be able to get the needed information from here(hopefully) tomorrow when I come in to work. Thanks again Joe and I have referred several friends to this site for their motor questions. "

"Alabama..... The easiest way

"Alabama..... The easiest way to find out if water is getting up to the thermostat is to take the thermostat out of the engine and leave the cover off. Start the engine.... the water should shoot up out of that area like a geyser. If it doesn't, replace the water pump assy (the whole water pump kit), not just the impeller. The pump kit assy is OMC part #382296 with a list of about $45/$50. The thermostat OMC number and superceeded numbers are #378065 ->393659 ->437414 ->434841 with a list of about $15. You should be able to obtain these from various stores. There are what is called "Heat Sticks" one that melts at a certain temperture, one that doesn't.... which would give you a general idea as to the tempertute of that engine. However, the best way is to pay attention to the water pressure that exits that rubber hose at the back of the engine. If a engine overheats to an extreme point, the pistons seize to the cylinder walls, resulting in heavy scoring, loss of compression (when it finally turns over again)..... in general, major damage could result. The good part about a small engine is that you are sitting right next to it, so if anything should interfere with the water coolant flow, you would spot it instantly. Unless you're running in a cold area with pretty cold water, you could run without the thermostat if necessary, but it's best to have it in there to obtain a proper expansion relationship between the aluminum pistons and the steel cylinder walls. Hope this helps.

Joe "