hpi apollo,

If you read my post you'll see that I understand how cold air is denser and all and warm air is thinner. What I was trying to say is that if I run in cold(er) weather say 45-50'F, the engine may warm up, but it will simply not run at optimum rpms, meaning it will run like it's too rich and just not have acceleration and speed. It's after a turn it a 1/8 - 1/4 turn leaner that it really starts to work right (smoke trail is just right, sound is just about crisp). In fact I seem to have better luck in cooler weather with respect to the engine running consistantly, while in warmer weather (65+) I'll usually have to go in and richen it as the tank gets low and it gets above 270'F if I don't. So I'm not disputing the "rules of r/c nitro tuning," but simply pointing out an interesting observation. BTW my truck body does not have open windows/windshield, but simply relies on the cooling hole I cut above the engine to shed the heat out, so at least that much is not keeping the engine from heating up in cold weather.

However, next time out in cold weather (whatever of it we have left here in Texas ) I'll try to cover some of the heat sink and see which way I end up tuning the needle, and the effects on performance. Again I don't try to use the HSN as a thermostat, but usually try to strike a balance between power and heat. Maybe I'm still wrong but hey can you blame a nitro novice for trying? I mean the Pro .15 manual says to keep it at 225, which I can agree is is kinda low, and here you guys are saying that engines *can* be run as high as 270'F range. Who do you suggest I trust with my $110? I think I'll strike a balance of both (if possible).