1992 150 Johnson Faststrike J150GLENC

I have a continuous solid alarm.

Have good, normal water Pressure. Replaced H2O Impeller about 2-3 months ago. Ran great since then. So I don't think its getting hot.

Didn't cut back while I was running...It will still run full RPM's.

Don't think there's a fuel restriction

WTH? Is it possible that the float in the oil tank stuck when I was running in the rough 4th of July traffic?

Can I check the cylinder head temps with laser thermometer? If so what is the temp supposed to be?