This is not a model site, but I have had it on my favourites for some time, and I'm sure many people have already seen it, but it should be of interest to some people doing conversions.

It is mostly related to full size quad engines, but there is quite a lot of valuable info in here (on the whole site) - suited to all two strokes.
( For those who want to use some imagination and initiative.)

http://www.macdizzy.com/cyl_primer.htm

Thanks for sharing. It is always interesting to know how the pros do things with the proper tools.

RCIGN should enjoy this IF it is a new site for him!