Well, I pulled the muffler off of the 250 tonight and went ahead done a small mod to it. I measured the hole under the louvers on the front of the muffler and it was 3/8" in diameter. So. I decided to increase the hole size by 50%, which figured to be 9/16", but not having a drill bit that large, I drilled it to 1/2" and then took a dremel and lengthened the hole, might went a little big, but what the hey. I then took a drift pin punch and opened up the louvers a bit, pulled off the limiter cap on the high side carb jet. The thing is really loud now, but it sure does scream. I pulled the plug after running it a bit and it was still a little on the dark side, but that will do until I get a tach. I hate to say it, but I think it might cut with my 488 now.