It had been running great prior to putting in the MS II.
So I doubt it is the carb jetting. They are 40 idfs with the CB rebuild kit that enlarged the venturi a bit (I did not see it at the site , so it may longer be available - forgot what you called it.) I did this about 3 years ago, and I trial and error-ed a few different jet combos. I can look it up - don't remember off hand. But after I got it dialed in, it has been running great for a few years.
I bought the coil and MS about a 6- 8 weeks ago. Serial number on the coil package says - CP - 160/2009
Thanks for taking the time to respond. I appreciate the help.