OS 160 Behaving Badly
Here's the scenario:
A new FX 160, OS #8 plug, stock muffler, 16X10 APC in an Ultra Sport 1000. Broken in with 5/20 (blended oil). Ran flawlessly for the break-in and 8 subsequent flights.
On 5th or so flight, I switched to my regular fuel, 15/18 (blended oil) and it ran great for 3 or so flights.
On the 9th flight, it flamed out about 1 minute into the flight, open throttle and straight and level attitude. On the 10th flight, same thing happened. No loading up, no sounds of running lean just before dying......it just stopped running.
Since then, running on the ground has yielded similar results, but I noticed it would often run fine until the glow driver was taken off. I then put a new #8 plug in, but that did not seem to help. I don't think the low end mixture is too rich, as it runs and transitions well without "4- stroking"
Do I have a mixture issue, or a bad fuel/plug combination, or what? I have never had this problem with a 2-stroke before.
Any thoughts? I appreciate any help anyone can give!
Thanks,
Stu