I bought a new TT 46 about three years ago and put it in a new WM Supersports 40S, which I am still flying. The engine instructions recommended a hot R/C long, "...such as K&B or OS #8."

I began using K&B plugs because they were cheaper. They worked just fine, and each one lasted a very long time, summer or winter.

I broke the engine in with 10% Power Master, and then switched to 15% Cool Power, which I now prefer and use exclusively. I wore out and replaced the bearings last summer with upgraded Boca Bearings. Then last winter the back of the muffler fell off in flight. I replaced the muffler with a Tower Hobbies semi tuned muffler. The engine is a real powerhouse, now!

Then I read this thread and decided to try an OS#8. (I have an old OS 40 four stroke, and the OS F is the only plug that works well in it.) However, the OS#8 in the TT 46 lasted less than a dozen flights! It may have run slightly better with the OS -- hard to say. I put a used K&B back in it, and it is working just fine so far. Go figure!

It has been very hot here lately. Maybe the OS #8 is a little too hot of a plug with the upgrades and the very hot air?

I just ordered some more K&B plugs.