I ordered 2 more today and had a nice little talk with Keith.
He said these twins liked RPMS below 7500 and the smaller port cylinders
may not be that big of a factor.

Right now I have 3 sets of cylinders 23.6 large ports, 21 large ports and 21 small ports.
So in the next couple of weeks I should be doing a lot of testing.

It looks like the average cost will be about $100.00 running on Gas / Glow.