1989 Johnson 60 hp

When running steadily at about 4500 rpms or slightly above, the heat sensor goes off and the motor quits running. If I wait for about 3 minutes, it will start back up and run again. If I keep it below 4500 rpms, it seems to run OK. I have had it to a dealer twice and the water pump has been changed and he removed the thermostat, trying to solve the problem. When it first started, I could start it immediately after it shut down, but now I have to wait a few minutes. I would appreciate any info on how to solve this problem.
Thanks......Yttapb

Re: 89 Johnson 60 hp

I'd replace the thermostat with a new one. Your engine is most likely overheating and after it cools down a bit you can restart it. Doesn't pay to run it without a thermostat.

Re: 89 Johnson 60 hp

can you hold your hand on the head when it stops running?
but I would think the dealer would find the overheat, but know knows.
let us know.

Re: 89 Johnson 60 hp

When your water pump was changed was it all there? Sometimes a piece of the impellor breaks off and could be blocking the water flow.

Re: 89 Johnson 60 hp

I have a 1983 E 175 that had similiar problems.
It would run WOT for a few min then bog down and shut off. Sometimes it would restart, sometimes I had to wait a few minutes.
Sometimes the overheat alarm would go off, sometimes not.
Then it got where I could run at 35 mph all day, but when I hit 36 mph, overheat alarm.
Did compression, found #1 cyl low compression. Removed head and found piston wall badly scored.
Rebuilt powerhead, #1/#2 cyl bored over to .065, new pistons etc..New water pump...blah blah blah.
Powerhead did the exact same thing on #1, actually melting the piston crown some.

Point of all this, warm up engine then shut it down and check compression!
Compression of 10-15% between all cyls ok
one cyl with low compression is probably the culprit.
2 adjoining cylinders have low compr, prob head gasket