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Johnson 60 overheat problem

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Izaac James

New member
Hi there,

I'm new to the boating world, I'm 16 and I've just finished building a 16ft speedboat with my friend from school.

We have bought what we believe to be a 1983 60hp Johnson electric start outboard for it, which ran brilliantly for 15 minutes on our first outing before the overheat alarm sounded.

I've spent quite a few years around car engines and the like, so I'm keen on the engineering side of things. We worked out how to get the impeller out, which was as good as new, which wasn't surprising as the person we bought it from said it had just had a new one fitted, and there was plenty of water coming out of the tell tale.

Annoyingly I forgot to check the temperature of the tell tale when we were out on the water, and I can't get the boat in the water again until there is a chance its fixed. However we did run the engine on muffs the day before and the tell tale was warmish after about 5 minutes.

Could anybody advise me as to what the most likely cause of this problem is? After letting it cool down we tried going fast and trundling around but either way the alarm started up again.

We don't really want to take it in for a service until next season as we can't really afford to keep servicing it and we are only looking to use it once more this year anyway.

If it's an obvious problem or there's something relatively cheap and only takes standard tools to install it, I'd rather spend the time doing it myself and save the money. If its a complicated problem though I won't try and do it myself and we will have to wait until next year :(

Thanks so much for your help in advance,

Izaac
 
maybe a bad head gasket. have you done a compression check, what do the sparks plugs look like?

i have changed my thermostat in my 1987 2 cylinder motor, it a pain in the ___ to remove the cylinder cover to get to the thermostat, its much easier to remove the head, then you'll get to work/clean up much more of the cooling system, a little more expensive, more gaskets to change, just say'n look at how to get to those bottom bolts of the water cover compared to the head bolts.

i did mine the hard way, that still didn't solve the problem, so removed head and found bad h-gasket.
but maybe the saltaway flush might be better if your only going out once more
 
Hi everyone,

Thanks for all your help.

I'm not keen on changing the head gaskets and removing the head and everything at this stage, but I'll definately have a look at the t-stat and pop-off valve. Yes it is a saltwater motor and I have got some Saltex I can run through it if that is the same as saltaway?

Could anybody give me any indication to where the pop off valve and thermostat are on the engine? I'm guessing they are on the cylinder head but I don't know what they look like from the outside casing.

Thanks again,
 
The model number is J60ELCTB and I've had a look at the engine tonight and it looks like getting the thermostat out is a fairly big job?

I'm not convinced that the engine's mounted too high, the bottom of the cavitation plate is exactly in line with the lowest point of the boat, and it overheats whilst trundling around as well, where I can see that the water intake is well below the surface of the water.

I think I'm going to try flushing twice through with Saltaway on Wednesday and then try it out on Sunday. If it doesn't work then I'm going to have to pack it in and wait till next year.

Thanks again,
 
Hello again. you can put it in boiling water and see if it opens but I would simply replace it as its not an expensive bit to change and if it malfunctions and overheats an engine badly you can say that you will be shortly needing an other engine. A good way to see if your engine still over heats and alarms is to remove the thermostat completely and give it a run. If it does not alarm then you found the source of your problem. A couple of runs without a thermostat wont ruin your engine. I had a 225 ocean pro that where completely removed and never replaced and never gave me trouble in all the years I owned it.
 
Hi all,

Got the thermostat out and replaced it with a new one. The old one was quite gunked up but when tested in boiling water it did still open. We figured it would be best to put the new one in anyway.

Unfortunately we didn't get a chance to run the engine through with the Saltaway, because the tub snapped and we don't have a hose pipe mixer.

Tested it on Sunday and it appeared to be a little better, however the engine did overheat a couple of times. I'm guessing this is due to the salt build-up, so I'll run some of the solution through it this week, but we aren't taking it out again this year and next year we will get a service, so I guess I'll never know :(

Thanks for all of your help, it is much appreciated!

Izaac
 
Hi, If you want to save some money, get the cylinder heads off yourself and clean the water passages. Head gaskets are inexpensive, you dont not need to understand how to time an engine like with a 4 stroke engine and and can be put on back together at the right torque of all the nuts with the right sequence. You can easily find information on how much torque you need to set your wrench to do it . Secondly it will help you understand more about your motor and will give you an other experience that you might need in the future to adventure repairing an other motor you might own . It can also save you a hell of alot of money.
Good luck
 
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