O K, I finally had a chance to read back a little way. I see I am re-hashing some stuff. Sorry about that!

The bearings have been looked over, I see

When I broke mine in, I tried to run a 12X6 right away. I was very dissappointed in the performance. By my 3rd tank, I put an 11X6 on it, and then things started to happen. I could litterally hear the engine go throught the transitions of break in. After a couple tanks on the 11X6, I tried the 12X6 again. It was all the difference in the world. Unfortunately, I don't remember any rattle. The performance got so good, I eventually ran it with a Zinger 14X6. I had it on a Dragon Lady. I did notice the engine was a little finicky with plugs. It liked the OS #8 the best, and I never had a flameout. I ran Omega 5%. We had a couple guy's with OS .91's and a guy with a ST.91, and the .76 outperformed them all. No competition at all. A friend bought a .76 for his trainer, and we broke it in the same way as mine. What a sweet engine! I think it even runs better than what mine did. After seeing how the guy's with the .91's lucked out, another guy talked me out of my .76. I bought the K&B to replace it, thinking it would give my Dragon Lady more life. It is probably my biggest RC mistake to date. I have the K&B running well now, but I had more verticle pull with the GMS. All the 1.00 did was allow me to take a lot of lead out of the nose.

I guess, in summary, try the #8 plug, and run a few tanks through it with an 11X6 prop. Perhaps it will let the animal lose, inside. If the rattle gets worse, I would box it up and send it back to MECOA.

Andy