Ringed glow engine issue
Hello fellow modelers,
I need some help with pointing out what the issue is or what I did wrong. I recently purchased an SK-80 ringed 2-cycle engine new. The instruction booklet that was included said for break-in to open the HSN to 1 3/4 turns from the fully closed position and start, then to slowly advance to full throttle and richen till you hear a "babble" and lean in just a tad till the "babble" clears and to run a full tank at that rich setting. I followed those steps to my knowledge but I only ran half a tank of 10% omega fuel. I used a 12oz fuel tank per the manual and a 13x6 APC prop.
A few minutes into the break-in procedure, the engine started to hunt and surge. I did not stop it when it happened though and let it run till the tank was half empty. I had the HSN opened to approx 2 1/2 to 3 turns out and was seeing blue smoke and oil spewing out of the exhaust. But when I measured the temp at the fins on the engine head, to my shock the temp gun was reading 337F!! I have verified that the temp gun is working correctly. Also, the oil spewed out was almost black and the top of the piston is covered with brown color. The fins also have brown spots on them.
Any suggestions as to what made the engine get so hot when I thought it was running rich and why the surge and hunting?