1983 Johnson 70 horsepower J70ELCTE cooling question.

[Big Bubba]

Good evening everyone,
I have a question on my 70 horsepower, 1983, model J70ELCTE Johnson outboard. My question is, is I was running my 20' Pontoon boat around pulling a tuber and had 6 people and gear such as a cooler, food, towels, etc. Anyway, I noticed when I first crank it up that a good flow of water comes out the two exhaust relief holes just under the cowling like it is running wide open but it isn't and it pees fine becuase I saw it peeing fine and I just replaced the water pump impeller about a month ago and yesterday was the first day I took it out to the lake. Now, after I pulled tubers and went to the beach to have lunch I took the engine cover off immediatley to see by hand how warm the engine got and it was pretty cool actually cool as a cucumber and slightly, ever so slightly warm around the spark plugs. I did not ever replace the thermostat since I have owned the outbaord and was wondering if the thermostat is maybe stuck open allowing water to circulate and have good water flow out of the two exhaust relief holes out the back of the motor on initial startup and continually there after. Last year, 2008, I rebuilt the carbs myself and got a mechanic to do a lync and sync for me. Is this normal and It doesn't idle as good as I would like it to also. It cuts out on me and I have to raise the warm up lever and then go with it. Do you think the thermostat maybe causing the motor not to warm up to normal temp could cause it to run like it is cold natured and causing it to shut off on me when I give it throttle?

[kenmyfam]

No harm in changing out the stat. Should be routine maintenance in my opinion. At least removing and checking it's function anyway. Balance of questions can be addressed after the stat is ruled out.
Wow, 20ft toon, 6 people aboard and tubing !!!!
I would say that motor is pretty strong !!!

[Sandhammaren05]

If the motor idles fine then you don't need a thermostat, it sounds like you have no problem at all. I always take out the thermostat on 2,3-cyl. OMCs and throw it away.

Good evening everyone,
I have a question on my 70 horsepower, 1983, model J70ELCTE Johnson outboard. My question is, is I was running my 20' Pontoon boat around pulling a tuber and had 6 people and gear such as a cooler, food, towels, etc. Anyway, I noticed when I first crank it up that a good flow of water comes out the two exhaust relief holes just under the cowling like it is running wide open but it isn't and it pees fine becuase I saw it peeing fine and I just replaced the water pump impeller about a month ago and yesterday was the first day I took it out to the lake. Now, after I pulled tubers and went to the beach to have lunch I took the engine cover off immediatley to see by hand how warm the engine got and it was pretty cool actually cool as a cucumber and slightly, ever so slightly warm around the spark plugs. I did not ever replace the thermostat since I have owned the outbaord and was wondering if the thermostat is maybe stuck open allowing water to circulate and have good water flow out of the two exhaust relief holes out the back of the motor on initial startup and continually there after. Last year, 2008, I rebuilt the carbs myself and got a mechanic to do a lync and sync for me. Is this normal and It doesn't idle as good as I would like it to also. It cuts out on me and I have to raise the warm up lever and then go with it. Do you think the thermostat maybe causing the motor not to warm up to normal temp could cause it to run like it is cold natured and causing it to shut off on me when I give it throttle?

[Big Bubba]

Yes, it doesn't idle to well on it own so I m thinking that the thermostat, IMHO, is stuck open and allowing it not to get up to its normal operating temperaure thus that is why it is not idling the greatest. It also could be the more I think about it that the 20 gallon built in fuel tank might have gotten some moisture inside because I actually drained all of the fuel from the fuel tank at the end of last season, September 2008, and left it like that threw the fall, winter, and beginning of Spring this year and then after I changed out the water pump assembly I towed it up to the local gas station and put 2 full cans of SeaFoam, the right amount of TCW-3 oil and gave it about 3/4 of a tank of gas and brought it home to run and test the water pump and submerged the lower unit in a big square trash can filled with water and ran it for about a good 30 minutes and she peed well but the motor never got hot like my other boat I had that had a 88 SPL V-4 model E88MSLCER Evinrude which I could only keep my hands on the heads for about a good 6 seconds before I had to remove them before I burnt my hands, now, for the 70 horsepower Johnson it stays very extremely cool throughout the run time and that why I question if it is suppose to run that cool. I will pop open the thermostat cap and see if there is actually a thermostat there and if there is I am thinking that little pin on the thermostat itself will be extended telling me that the thermostat is stuck open and I need a new one. Also, I remember that when I ran my motor in the trash can that there was alot of hard dirt black chunks floating around in the water, is that carbon deposits...Thanks Bob

[Big Bubba]

bump...

[Sandhammaren05]

You need a fuel filter between the tank and motor. Evinrude sells a solution that you can add to the tank, when fuel sits in it a long time, to prevent the alcohol from helping to collect moisture. Not clear that the idling problem's the thermostat, in warm weather you ought to be able to idle ok without one. A cool motor's a lot better than a hot one. also, buy a flush attachment ($8) instead of filling a garbage can with water.

Yes, it doesn't idle to well on it own so I m thinking that the thermostat, IMHO, is stuck open and allowing it not to get up to its normal operating temperaure thus that is why it is not idling the greatest. It also could be the more I think about it that the 20 gallon built in fuel tank might have gotten some moisture inside because I actually drained all of the fuel from the fuel tank at the end of last season, September 2008, and left it like that threw the fall, winter, and beginning of Spring this year and then after I changed out the water pump assembly I towed it up to the local gas station and put 2 full cans of SeaFoam, the right amount of TCW-3 oil and gave it about 3/4 of a tank of gas and brought it home to run and test the water pump and submerged the lower unit in a big square trash can filled with water and ran it for about a good 30 minutes and she peed well but the motor never got hot like my other boat I had that had a 88 SPL V-4 model E88MSLCER Evinrude which I could only keep my hands on the heads for about a good 6 seconds before I had to remove them before I burnt my hands, now, for the 70 horsepower Johnson it stays very extremely cool throughout the run time and that why I question if it is suppose to run that cool. I will pop open the thermostat cap and see if there is actually a thermostat there and if there is I am thinking that little pin on the thermostat itself will be extended telling me that the thermostat is stuck open and I need a new one. Also, I remember that when I ran my motor in the trash can that there was alot of hard dirt black chunks floating around in the water, is that carbon deposits...Thanks Bob

[Dhadley]

With todays fuel you need to make sure the t-stat is in good working order for good idle quality. "Back in the day" when we had better fuel removing the t-stat wasn't as critical. Unfortunately we don't have that fuel any more. Also make sure you have fresh 87 octane fuel and the right Champion plugs. If your fuel is more than about 45 days old, get rid of it. It'll probably run OK in your truck but it's not good for outboards.

[kenmyfam]

I'm with Dhadley on the stat

[Big Bubba]

Dhadley/KennyFam,,
I will buy a new Thermostat kit and change it out. I have this strong feeling that the thermostat is stuck open and that is what my problem is. Last year I don't really remember that much water comming out of the exhaust relief holes. Where do you recommend me buying one from Ebay or the OMC dealer in town. I heard that the aftermarket ones fail to the closed position and the OMC ones fail in the open position so they say to get the OMC one for that purpose. Your thoughts...

[kenmyfam]

Personal choice is the OMC version. Never had an issue to date with them. Change out every few seasons for the heck of it and know I have some working spares should the need arise.