Link to this "rexon" engine you're talking about? I can't seem to find it.

Yeah, increasing compressing is the next thing I'm going to try. I tend to err on the side of not enough compression, because it reduces the risk of rapid overheating if I forget to check the engine temperature every single minute during initial tuning. When I first started with nitro I started with off-road trucks, which put much more continuous load on their engines as they drag themselves through the grass, and I still haven't successfully adjusted my thinking for on-road engines to account for the lower continuous load and much higher airflow. I already increased the compression of this engine once, but I have a little more room to increase it some more; it seems to be running unusually cool right now, and takes several full-throttle passes in a row before it gets up to what I would consider a high temperature.

When the weather warms up again and the engine starts running hotter because of it, will installing a colder plug be an acceptable adjustment, or will I have to reduce the compression and/or tune it richer again, thus giving up whatever power increase I might get from the increased compression?