TOPIC: Engine surface temperature?

I've done a brief tank test on my 7.9hp Champion outboard, but before we take it out for the first time I'd like to do a longer test in order to monitor temperature. I plan to use a hand held thermal sensor gun to monitor temperature. What would be a reasonable operating temperature at the exterior surface of the head? At what temperature should I get concerned that it's getting too hot? I realize this is not going to be extremely precise.

If has more than one cylinder watch to see how even the temperature is cylinder to cylinder.

My "outboard mentors" always told me you should be able to lay your hand anywhere on the motor without burning yourself. Not sure what that temp would be, but probably under 100 degrees?

I'd also be careful about judging it sitting in a tank. The water temp itself will get higher pretty fast as water from motor will be hot, so temp will just keep rising. Best to run it in tank, make sure it shifts well, and take out on lake to actually test cooling...

Ditto what Mark said. Using muffs will give a bad cooling read because you're pushing cold water from your tap into the system helping a possible bad/worn impeller. Use a tank or garbage can. You should be able to hold your hand/fingers anywhere on the block. Stay clear of moving parts!

Out on the water I would not expect to see over 110-120, and more likely around 70-90, unless the lake is really cold - then of course maybe even a lower temp.
If it is an open end cooling system without thermostats, it shouldn't get very warm, until after you have turned it off. Then the temp of the block might climb to 120ish.
doc

Sounds like my hand and the lake are the only tools I need. Maybe I'll take some temp readings while I'm on the lake, just for science. Thanks everyone for your input.