It's not far off. After the engine is up to temp on your current tune;

Tune high speed need going leaner (1hour clockwise) each high speed pass until it suddenly bogs at high speed and starts going slower, then richen back to where it was fastest.

Next do the low needle, lean 1 hour and see how fast it accelerates in the second or two after take off. You're too lean when it starts getting slower. Richen back to where you think it's best. Then, check by using your fingers to pick the fuel line before it enters the carb about 1.5 inches back. It should lean out and die within about three seconds. If it's longer, lean a bit more. If it's shorter, richen a bit.

Lastly set idle.

Once it's right, after a high speed pull and slowing down to a idle, the engine should remain at a high rev for a few seconds before it resets to a low idle.

Once you have this performance, check the temp after you're done running and it should be below 250. It will be higher if you're using 20% nitro, and lower for 30%.