912UL stiff prop
Our small group have an EV97 with a 912UL fitted that has performed flawlessly since new and now has around 750 hours on it. One of pilots mentioned that he was finding it a bit more difficult to put it through (to return the oil prior to first start of the day). Several weeks later while in the circuit the aircraft developed a distinct vibration bad enough for the pilot to declare a PAN and return to the field. The vibration was repeatable on the ground. Our engineer found very fine metallic particle on the magnetic plug and in the oil filter. The gearbox has been recently overhauled and is exonerated. The prop is now extremely stiff . We have followed the advice from this forum about crankcase fretting and loosening cylinder 2 make no significant difference to the tight feel.
We know a tear down or new engine is probably inevitable. We have a spare 912S(by fluke) has anybody any advice as to the difficulty of moving from a 912UL to 912S in terms of mechanical issues and more importantly (in some cases) paperwork .
Any advice?
Thanks in advance
Joe