1980 150 Black Max leaking head gasket? (photos)

[Dukedog]

will help ta chase threads, clean bolts and apply a light oil to 'em............

 

[NWChris]

Thanks Dukedog! I've just done that. My spaghetti thingy should be here on Tuesday.
I found this link that mentions using loctite for the bolts. But I'm not sure I like that idea as how could you re-torque the bolts after a few hours of running?
-Chris

 

[NWChris]

That link didn't work right. I'll try again:

http://corboatracing.com/downloads/mercury-2.0-liter-torque-specs-2.pdf

-Chris

 

[Dukedog]

that time thing is mainly for head bolts which no loc tight is involved........... heat/cool cycles is really what ya need ta go by.
never hurts ta check "all bolts" ever so often ta be sure

 

[NWChris]

The grey water/oil on the spark plugs is gone now!
But the plugs are still coming out a bit wet (dark oily). They are all the same except one plug that is not firing at all. I measured its resistance and sure enough it shows 200 kOhms or so. I have a new plug coming (I live on an island), but noticed something weird: The side of the motor with good plugs gets hot at WOT, even when I move the bad plug to the other side. It actually set off the high temperature alarm. I'm not sure my cooling water flow is 100%, I'm getting some water out the poppit valve hole (I am going to order new diaphragm and gaskets). I've pulled both t-stats and they open perfectly at about 140 deg F. If I run the motor for a second with the t-stat housing off I get lots of water pouring out at good pressure.
Anyhow, good progress and I see the light at the end of the tunnel! Thanks for the help all (especially Dukedog).
-Chris

 

[NWChris]

New spark plug today, and both sides of the engine are now the same temperature, interesting. I used one of those little infra red thermometers, and got about 125 deg F on the side of the blocks, and about 115 deg F on the side of the heads after a fast 5 minute run. The engine sounds like its missing a cylinder now and then below 2500 RPM, and the plugs are still coming out a bit wetter than I'd like, but I'll pursue that another day.
-Chris