Apparently KTM Duke IIs are known for their fragile clutch side Input Shaft bearings. A customer had come to me with the replacement part number from KTM, and although the Bearing was available, KTM will not warranty the labor to install it.
After removing the clutch side engine cover, clutch hub, basket and oil pump gears I knew we were in for a battle. The stock bearing is a ball-type roller pressed into the aluminum case, proper removal would require splitting the cases. Duke II cases are vertically split, which would mean that the entire top end would have to be removed to get to the case halves.
I talked with the customer about the problem, he in turn called a friend of his in England who owns a KTM dealership. The dealer had done dozens of them without splitting the cases by welding a pipe to the old bearing and back-hammering it out. I agreed to give it a try.
Last night we took the bike, my slide hammer and the new bearing over to Dave Adolfson's machine shop in South Saint Paul. While I pulled the gas tank and ran for dinner Dave turned up a puller that would screw right into my slide hammer shaft and an installer that fit around the input shaft and was long enough to drive the bearing home.
We then welded the puller to the bearing and, after getting the bearing to move slightly the slide hammer broke some of the welding and almost came free of the bearing. We rewelded and, a little more gently this time, back-hammered the bearing out.
The new bearing is a barrel roller type and looks to be considerably stronger, certainly it wasn't cheap, about $90. With some heat still in the cases from the welding the new bearing went in without much of a fight, the tool Dave made kept it perpendicular to the shaft, keeping it from cocking.
My only complaint about the whole process is that I can't do anything about the input shaft endplay, we just have to trust that it remains in the ballpark. The process saves anywhere between 10 and 15 hours in engine removal, disassembly and assembly, not to mention gaskets and other sundries.
I'll post some pictures of the tools and bearings in the next week or so.