I recently purchased a boat that has 2 1986 Johnson 70 motors on it.
On the first run out we noticed that the temperature guage for one of
them went up to the top of the red while the other stayed in the
bottom 1/3rd of the green. We stopped the motors and took the covers
off and put our hands on both of the heads near the spark plugs. The
one that had stayed in the green was barely warm and the one that was
in the red was hot enough to bother your hand if you left it resting
on it for 30 seconds. We had actually never gone more than about 1/3rd
throttle on either engine for no more than about 5 minutes. And the
one in the red had only been at idle except for about 30 seconds when
I had put it up to about 1/3rd throttle. The pee stream on both motors
looked good. But on the one that was in the red, the pee stream was
even stronger - actually stronger than I have ever seen on outboards.
I replaced the thermostat because I was thinking that the impeller was
good because the pee stream was so good. But it still climbs up to the
red after just a few minutes at idle - and then the powerhead feels
hot to the touch - not like it burns your hand - but again
uncomfortable if you leave your hand on it for a while. Any ideas what
the next step should be? I called the local boat guys and they are all
at least 2 weeks out and halibut season opens Thursday - so I would
like to get a chance to use the boat before 2 weeks from now.


Thanks,
Eldon