Ok so I actually used one of mine for the first time today, the one I got just recently, I slapped on some wheels from an old rover 4 stroke off my scrap pile, put in a new rope, cleaned the carb out (these seem to like caking on dried out fuel in the bowl) cleaned out the jet and took her for a spin.
it runs smoother than a victa twin, took down any grass I threw at it without it even trying hard on the govenor and seems very economical.
My other one which I have used must need a good tune as this one is really good. It is one of the late model ones with the new steel type rover base.