Thanks again for all the great advice.
-The bike idles on the stand well and I have checked for leaks with carb cleaner. I did thorough breaking in on the old Bing 12.
-The rear sprocket has 52 stamped on it. If it's actually a 45, whoever stamped that 52 is missing out on the punchline. My front sprocket I swapped in is a 18, not 19T. So it puts me close to the stock ratio.
-I let the cylinder break in idling on the old Bing and putt putts around the block for several days. I'm still avoiding constant throttle etc.
Does one need to Run break in cycles every time after pulling the head? I have replaced all the gaskets and I think she is pretty tight. Didn't deck the head or anything, but I use a torque wrench.
-Today I mixed up and loaded some 60:1, about half the oil than I had been running during break in.
-I ordered a temp/RPM gauge, lesson learned.
It seems to sound a little better on the stand running the spec oil mixture and the taller gear. I didn't have the opportunity to test ride much, but it kind of felt like it did the trick putting redline further out of reach may have been all I needed, but waiting for the sensor.
I did some calcs and I was probably going up to 10K rpm when I had that soft seize. I'm waiting for the rpm/temp gauge to come in before giving it the beans.
Taking a closer look at the timing is on my list. With the temp sensor, if I adjust my timing, can I look for a temp difference at idle or would it only show running a route and watching temps?