RCU Forums - tunning tips

just follow this breakin:

From the very 1st time you start your engine, plop the car on the
ground & begin running it in a parking lot in 2-3 minute intervals,
tuned only *slightly rich* getting the temps up in the 200F range on a
normal day. Every 2-3 minutes, shut the engine down & let it cool
completely with the piston at BDC, and then fire it back up; continue
this cycle until you've run 15 min or so, and then bump up to 3-4
minute intervals. Vary the RPM and don't be afraid to get the temps
in the 200's. What you want is heat cycling of the components without
the incredible stress that comes with breaking an engine in when it's
overly rich & cold. After cycling the engine in this manner for about
20-25 total minutes, it'll be ready for the track and race tuning.

NOTE: this is not mine and was borrowed from Stephen Bess and other experts that came up with it....

also use tin foil around the head to heat it u better...

In general for nitro engine, you should run anywhere from 200 to 260 degrees Fahrenheit. Anywhere below 200 and you're running the engine too cold and when you run a too cold, the sleeved does not expand far enough and pinches the piston more. Running an engine this tight will cause premature wear because the tighter the piston and sleeve is, the more wear it is on the piston. Then again running it to lean will also cause premature wear due to the engine not getting enough lubrication.

Here's how to tune a motor:

First start the engine up and run it around for about three minutes. Run it really hard like you're racing around a track. Then do a couple of full speed passes, after each pass lean the needle 1/8 of a turn each time. The car should get faster and faster on the top end. Eventually you will reach peak horsepower and after that each time that you need the motor, the power will decrease. At this point go back to the peak horsepower setting, and rich it a 1/4 to 1/2 of a turn. Your car should have plenty of smoke this time coming out of the exhaust. Then bring the car in after a full speed pass and immediately let the motor idle while you pinch the fuel line anywhere. The engine should cut out after about four or five seconds. The engine should also rev up before it shuts down. If your engine shuts down before four seconds or it doesn't rev up, then your engine is running too lean and I would richen it immediately anywhere from 1/8 to 1/4 of a turn. After you've tuned the low-end correctly, then you can adjust your idle speed. This should be adjusted so that the engine does not engage the clutch at idle.

I hope this helps,
Erik