Dave,
Welcome.

Al gave it to you in a nutshell. I'll just stretch it out a bit.

Lean it out enough to get it to run at full throttle. Run out most of another tank (at least) like that. Then lean it more until it breaks into a "2 cycle" run. Leave it for a few seconds (10 - 20), then richen it back to a 4 cycle run.

Once you've gone back and forth between 2 and 4 cycling for a while, you can let it run longer in the 2 cycle mode. I'd run it 2 cycling for 2 or 3 minutes, then shut it down and let it cool off for 5 to 10 minutes. Restart and run it again for 2 to 3.

All of this breaking in should be done at full throttle by the way. (But throttling back every once in a while won't hurt anything.)

I'd do the above through 3 to 4 tanks. Then lean it out enough to fly with it, but keep it on the rich side for the next few tanks. (I always run my engines rich enough so that they "burble" a little when throttle's backed off, and my engines last forever.)

Good Luck,
Dennis-