Hobbsy, I use a 13.5 x 6 (carbon bolly) on my YS 63 to great effect in Duration. Might I suggest that you try a 14x6 as an alternative, same numbers less pitch. IF it doesn't turn that prop with good revs (on 15 to 20% nitro) I would suggest moving it on or a serious overhaul. I will be using an 82 in my DVii once I get it out of the box so I will be better able to comment after it has been run. Has any one done an audit of their kit collection? My mate and I did the other day, my score was 15 scale, 5 sport, and 8 Old Timer kits. This comprised full kits, short kits and curses ARFs. Un finished projects amount to 10 and repairs amount 5 (in various stages). Plans stopped counting at 100 of various types but some need re copying. It is amazing what you find when you go looking. In my case I was finding my data on the Boomerang fighter that eventually was passed onto a fellow modeller. I am seriously considering getting the lot scanned and stored electronically.