Hi guys, I did some work to my 2100 on my 289. Rather than trying to hunt down a different carb with the larger venturis, I simply took a die grinder and ported out my existing carb. My venturis are now 1.25", and I will probably go larger next time I have it apart. I had to jet it up some since there is now more airflow through the carb for a given pressure drop across the venturis. It runs great and seems to have picked up some power. I went from 48s to 59s on jetting, but that might actually be too much because after I finished I discovered and fixed a vacuum leak (stupid choke! didn't realize that broken tube had vacuum in it.) I think 55s are about the right size, or thereabouts. I gotta check my plugs and see what they look like.