Problem solved.....

I no sooner got to the flying field and took the os#8 plug out and replaced it with a good ole "fox standard long glow plug". After a few minor adjustments on the groung with the low and high end needles, getting it tuned up, the crackling sound nolonger existed during my 1st flight.

Engine runs smoothe as ice now. New fox glow plug and some tweeking on the needle valves is all it took for my os engine to live up to its name once again.

Actually I blame it all on that new os#8 plug I had previously had in it. Now I am running a 14-8 prop at 8900 rpm (for now) and still get unlimited vertical, just takes a tad longer than the 13-8 took.

Thanks for all the help and advise.