T28Ron, If it were my engine and I had bought it used like you did, I would go back to step one in the break in procedure. Especially since you say the previous owner said it had only been run once. I would remove the engine from the plane and put it into a mount, but first i would pull the head to make sure everything inside the cylinder was fine. Last winter I burnt a piston in my moki 2.1 after I stupidly thought I could switch to 10% nitro with no added oil. It burnt a little of the piston off right behind the exhaust port, no cylinder damage, and the engine would turn over, although it would not run for very long. I finally discovered the problem and replaced the piston and everything is fine now. Anyway, back to break-in--Maybe the guy you bought the engine from didn't breakin the engine correctly if at all. So, I would mount the engine upright in the mount, I use 5% nitro with 16% oil content and then add 2 more ounces of oil --I used Klotz Super Techniplate 2-stroke racing synthetic with 20% castor to the gallon of fuel. If you are using the cline regulator, then fill the tank with the fuel mixture, then pull all the fuel through the cline regulator by using you fuel pump, this should make sure there are no particles clogging the cline. Next refill the tank, make sure the cline regulator is close to the carb, mine is about 3/4" away. make sure the idle adjustment marks are lined up, and then open the fuel mixture (needle valve) to about 4-5 complete turns open.You will have to run the engine this way with the glow plug connected to a power source until breakin is complete. Run the engine for a few minutes to heat it up, then shut it down and let it cool, keep doing this 2-3 minute run-cool down cycle for the firt two tanks, then allow the engine to run longer (still rich) until you've gone through a gallon of fuel.These moki engines take a long time to breakin. Breakin should be done with a 20x10 prop. I am now flying with a 20X8 prop, and I use pro-zinger wood props.My needle valve is opened to 2 clicks under 3 complete turns open and my idle adjustment is just a hair to the right of the mark. But, since I am in New Mexico at an elevation of 4000+ ft, I believe my adjustments will be different then yours in peoria Arizona. Remember after breakin, to make the needle valve adjustments to get a good responsive mid- throttle running engine, get everything running good at mid-throttle, then if you still don't have a good idle tweak the idle adjustment a little, but always go back and make sure your midrange is perfect. Hope this helps!! let me know how it worked out because most people on this site don't have to deal with these high desert conditions.