Vette- I've had a good many Evolution 46s, and a couple of other sizes. All of the Evo glow engines that I know of need the OS A3. The 8 is too cold. All of these engines will wake up and howl with the A3. I've had many hours on many Evos with the A3 and 15% fuel without any problems.

The Evo will bog down and sound like it is gurgling with a cold plug. You may find that you have to milk the throttle when first starting with an OS 8. Also, they load up with fuel in the crankcase with the OS 8. The A3 cures all of those symptoms. However, a lot of people think the A3 is too hot until they see how the engines run better.

Can you put the original muffler back on until you get it tuned more closely? That would be the best solution for right now.