60hp Johnson overheating

[Liam]

I recently spun the prop on my 60HP johnson outboard. I left the prop in for two weeks to have a new hub pressed in. When I went to pick it up he realized he had not sent it in at all!<br /><br />He loaned me a 15 X 12 3/4 prop to use instead of the 17 X 11 3/4 I had. When I used it the engine overheated.<br /><br />Is this caused by the prop as it never overheated before?<br /><br />The engine cut out as I was coming into the dock at low revs. What do I check for damage?<br /><br />If I placed the washers incorrectly, would this cause the problem?<br /><br />How should I handle the boat from here? Take it out and retry, change the water pump? Pull the boat and the motor for checking?<br /><br />The water was coming out the pee hole but was sputtering and hot.<br /><br />All help is greatly appreciated.<br /><br />Thanks,<br /><br />Liam

 

[Joe Reeves]

Re: 60hp Johnson overheating

Liam.... What year is that 60hp? If you're not sure, what is the model number?<br /><br />The smaller dia prop with a larger pitch shouldn't have had any effect which would lead to a overheating problem.<br /><br />There is a large thrust washer in back of the prop and a star washer between the prop and the prop nut.... I don't see how you could confuse the two.<br /><br />The engine should have a warning horn system that would have sounded off long before the engine was hot enough to do any damage. Do you have that warning system.... did it sound off? If you have no warning system and ran the engine until it started to seize, check the s/plugs for water, tighten the cylinder head(s), and if there's water in the cylinders, or/and low compression, remove the head(s) and install new gaskets. Obviously you'll need a new water pump.

 

[Liam]

Re: 60hp Johnson overheating

Thanks Joe,<br /><br />As usual the members of this board are outstanding!! The motor starts now but will not tick over. The engine did not seize but did stall when I dropped the revs. The water pump still works well, but I will change either way. My concern is why it would overheat initially. If it is not the pump (I don't know yet) what else could cause it? Also, I will check the heads and plugs and compression. If all is OK, or I tighten the heads slightly, should I look out for anything else?<br /><br />The motor is a 1984 two-lunger Johnson 60HP.<br /><br />Thanks,<br /><br />Liam

 

[Joe Reeves]

Re: 60hp Johnson overheating

Liam.... That engine should have a heat warning system (horn). You didn't say but I am assuming that the horn did not sound off, and if so, find out why as that's the only warning you have! With the engine not running, with the ignition key in the on position, ground out the heat sensor (tan wire) wire that is protruding out of the cylinder head. That grounds the heat sensor and the horn should sound off.<br /><br />If the engine did actually overheat, and the water pump is functioning properly, it's always possible that you picked up something momentarily (usually a plastic bag) which would cut off the water supply..... and when you stop and tilt the engine, the bag drops off which creates a mystery of sorts.<br /><br />What do you mean by "the engine will not tick over". I'm not familiar with the "tick over" saying.<br /><br />Let us know what you find out about the warning horn.

 

[Liam]

Re: 60hp Johnson overheating

Thanks Joe,<br /><br />By tick over I mean run at idle. If I increase the revs she runs fine. I may have to retighten the head bolts after the overheating. If it is sucking air it will not run properly.<br /><br />Also, It appears the engine does not have a temp sensor. How much do they cost and are they easy to install?<br /><br />Thanks again,<br /><br />Liam