I'm building a 30 year old Mk2 kit right now. Its going to come in somewhere around 4lb soaking wet ready to fly since I made some strategic wood substitutions rather than use the warped iron wood that came in the kit.

The Mk 2 is not a large trainer. It would fly fine with a modern .25 or older .29/.35. I may wind up with an FP .35 in mine, since they run fine on no-nitro FAI fuel and will produce more than enough power to fly the plane with no nitro.