Engine Temperature / Gauge Reading

[tastade]

What temperature should the gauge read for the M42 (or M44)? Mine read low a while back, so I changed the thermostat and it fixed it so it always ran exactly mid-range. However, I just changed my spark plugs and noticed that it is now reading just below mid-range. It is now halfway between mid and the next cooler tick mark.

I don't imagine that chaning the spark plugs could lower the engine temperature that much. I am now using the BKR6EQUP with Bosch wires. I think the only way the spark plugs could reduce engine temperature that significantly was if detonation was occurring, which I neither heard nor saw signs of.

Maybe I had another problem show up at the same time as I changed my spark plugs, or maybe I fixed a problem I was having by changing my spark plugs, so my basic question is: Is this where the gauge should be reading and it was reading high before (exactly straight up before)?

[Bluebimma]

The temp should be at the vertical mark rather than above or below. My temp gauge usually reads right on the mark or a smidge below it.

[ASRACER4]

what he said i had the same problem with the thermostat.