After a partial seizure I have replaced my engine with a (hopefully) better one. I have rejetted it, adjusted the oil pump etc and it runs quite well.

BUT... After draining and replacing the coolant and hooking everything back up I noticed that the temp gauge didnt move when running.

I made sure that the coolant had circulated into every pipe, and I thinkI got all the air out in the first running sequence. So if the coolant is circulating (I think it is...) why would the gauge not work with the new engine. Have I missed something when reinstalling the engine? Is it possible that the thermostat is faulty or disconnected?

Also, is the speedo cable for the MC21 the same as the NC30 one?

Cheers guys.

das134 wrote:After a partial seizure .....

It's not quite dead... just partially dead

The thermostat should have two connection. Check they're both fitted. One's a bullet type to the sensor, and the other's a spade type to earth the housing.

Right, I've had the same issue with the ground (spade) connection. Just plug it and ready to go.
_________________

Sounds good, I'll give that a go. The needle does move (just) when the bike is switched on. Would this still happen if it's just not quite connected?

Exactly. Your gauge is alive. There is a test method to check it, If you want to make sure. I Just don't remember where I saw it. Look for the earth wire and connect it as Matt indicated.
_________________

Two minutes and look at that! A working gauge. The spade type connector wasn't connected quite right but now good to go. Big relief, nothing like riding a two stroke with a new engine with NO idea of the temperature.