I've wondered the same thing myself...just how *DO* you know your
little 2-stroke is overheating, without actually seizing the piston and
finding out the hard way.
About the engine dying when you pull in the clutch, mine started doing
that after a couple hours of runtime...turns out that cheap asbestos
looking gasket that came with the kit to fit between the intake and the
cylinder head gave way, and was letting in too much air.
I made a new gasket out a thin cardboard and RTV silicone. Worked
like a charm, and fixed that whole "won't idle" problem.
BTW, that can be a serious problem, too much air coming in from a
leaky gasket. Creates a lean condition... more heat, less lubricant...
standard issue