The Asp engine may be a tad over-compressed. Previously distributed by Indy RC -- now extinct -- and the Horizon, I do not know who imports it now. The 40/46 are excellent but not long-life like a ST that never quits.

I have used the .75 and the .90 which were over-compressed. I do not know about the .61.

You can make another head gasket from a pop can material, cut inner hole with X-acto #11 blade and then trim the outer rim.
Easy to do and works well to decompress engines originally made for no-nitro markets outside the USA.

Don't worry about settings as the 2-stroke glow engine has its own mind there. Close the throttle to about a hairline open, and set the idle needle so that you CAN but BARELY blow air through the carb. Then open the carb and set the NV to where it will pass some air but not all at once. Go from there. Generally set the high end first. Sometimes one might need to leave the glow plug connected through the transition to open throttle to be able to set the high end. Once done very well there, start with very small idle adjustments.
May take some trial and error, however you will learn the code.

Suggest you start a flight at least 700 RPM down on the rich side. The ASPs are powerful engines. Overly lean can provide significant practice in dead-sticks. [8D]

Good Luck.