60 hp getting hot

[nmhellraiser]

I'm helping my grandfather work on his 1984 60hp evinrude. He's having an issue with it getting hot and the overheat alarm sounding. I helped him put a new water pump in it and it's installed right. We changed the thermostat and poppet valve also. It's still getting hot though. We took the lower unit off and pulled out the thermostat and used compressed air to verify that the pickup tube isn't stopped up. Also boiled water and made sure the thermostat was opening. We're getting a good stream of water out of the tale tail. Compression is 150psi on both cylinders. What are we missing?

 

[oldcatamount]

Re: 60 hp getting hot

Try this; take the thermostat cover off and take the t-stat out again, use a piece of weed whacker string to work through the water ports in both directions. You may be surprised at how far into the motor you can work the whacker line.

 

[nmhellraiser]

Re: 60 hp getting hot

Ok, I'll give that a try. I did blow compressed air through there yesterday and was able to hear it coming out the port in the lower unit. It's only has one opening for the water go into. This motor is two cylinders. I'm to the point where I'm going to pull the head off and see what's going on. Everything else seems to be in the correct working order. Was thinking someone else has seen this problem before and could shed some light if it's something simple but I honestly feel that I have an occlusion or something in the water passages inside the head. The only other thing that I could think of would be the temp sensor in the head. The T-stat is set to open at 143 degrees and it does. I have a thermal thermometer and the temp on each cylinder when the horn goes right at 175 degrees.

 

[oldcatamount]

Re: 60 hp getting hot

The t-stat housing will have two openings inside it (water in, water out). If you only see one, that's probably where the blockage is.

 

[mark mcj]

Re: 60 hp getting hot

Are you getting the overheat alarm at idle speeds?
Mine will sound off after 4 or 5 minutes of idle speed operation.
Any speed over slow idle and it's fine, even warm high speed idle using the cold start lever.

BTW mines a 82 60hp twin.
New stat, tested to open at 143.
New poppet, new water pump, overheater sensor triggers at 165
I just ran it for 20 hours over the past 8 days and it runs great. Easy starts, very good top end and good gas comsumption.

 

[nmhellraiser]

Re: 60 hp getting hot

The t-stat housing will have two openings inside it (water in, water out). If you only see one, that's probably where the blockage is.

It has 2 opening. The pickup tube to the t-stat opening is clear. The port to the inside of the heads seems clear but I can't see all the way around it without taking off the head. I put a pressure gauge on it at lunch and I'm getting 12 psi idleing and almost 20 psi with the cold start lever up. I'm thinking somethings up inside the heads. I'm going to take it off after work today.

 

[nmhellraiser]

Re: 60 hp getting hot

Are you getting the overheat alarm at idle speeds?
Mine will sound off after 4 or 5 minutes of idle speed operation.
Any speed over slow idle and it's fine, even warm high speed idle using the cold start lever.

BTW mines a 82 60hp twin.
New stat, tested to open at 143.
New poppet, new water pump, overheater sensor triggers at 165
I just ran it for 20 hours over the past 8 days and it runs great. Easy starts, very good top end and good gas comsumption.

The alarm sounds about 5 minutes after being started on the muffs.

 

[mark mcj]

Re: 60 hp getting hot

The alarm sounds about 5 minutes after being started on the muffs.

I'd try to run it at a higher RPM level. Get it out on the water and run it at any RPM other than just idle. I think this motor isn't really designed to be run at idle for long periods (5 min) of time.

 

[nmhellraiser]

Re: 60 hp getting hot

The curiosity got me. I pulled the head off. Here's what I found. I know now why the alarm was sounding. Input on what caused this?

 

[Monte1961]

Re: 60 hp getting hot

That would be a good indication! Good luck and let us know how you make out!

 

[Daviet]

Re: 60 hp getting hot

Make sure the head is not warpped before you put it back on.

 

[nmhellraiser]

Re: 60 hp getting hot

The head doesn't seem to be warped but all i have is a true straight edge to check it and everything seems to be ok on it. I don't think it ever got that hot. My grandpa is a little anal about things and never put it in the water after the horn started sounding. Head gasket will be here tomorrow so I'll post up results.

 

[nmhellraiser]

Re: 60 hp getting hot

Alright, put the head gasket on yesterday and torqued everything to specs. Put it in the water and it runs like new again. Pretty simple and straight forward swap. Luckily this was a freshwater motor or bolts might have been broke.

 

[Monte1961]

Re: 60 hp getting hot

WTG! And thanks for posting back.