Originally Posted by Nos4r2
....you could simply clamp an overheat sensor from a mariner 2-stroke to the exhaust in the same place then-cheap and simple.
Yep, temp sensors are freely available and cheap and a wee circuit easy to make.
However, a temp gauge linked to an exhaust sensor gives a bit of indication of how hard you are running the engine. It can cheat you though if the engine gives a rich mixture at full throttle cos the excess fuel lowers the exhaust temp.
I use a combined turbo boost/temp gauge. The boost tells me how hard I'm running the motor and the gauge keeps a eye on the exhaust temp. It has settable alarms. The down side is, it's not cheap.