Update time!
So after doing a lot of research and tinkering around, I thought I could remove the (supposedly) bent shift fork(s) through the oil pan. I read a post that explained how to do it on a zx6r, and the engines seemed similar enough to make it plausible. My buddy came down this weekend, and after removing the headers, covers, clutch, oil pan, and oil pump, we realized that there was no way to get them out without splitting the case.
I briefly considered throwing in the towel at this point, but I was convinced otherwise. We pulled the engine out of the frame, cleaned it up, and started taking it apart. Here's how it looked once we got the engine out:
Next, we pulled the head cover, cam shafts, head, and cylinders off. At this point, we noticed that the pistons and valves were NASTY. I know it's normal, but we were still surprised at the level of gunk baked on in there. We went to town with brake cleaner and elbow grease and cleaned that crap out.
After two passes with brake cleaner:
After five passes with brake cleaner:
Here's where it gets good... So we're busily getting ready to crack the crank case open when my friend goes "Oh... What's this?" It turns out that the whole issue was caused by a small broken spring in the shift linkage assembly (part 92083 below)... This part costs all of $5, and getting to it is a quick 5 minute job. UGH. So we wasted a lot of time and effort for next to nothing...
But we were pretty happy with all the work we did, in the end. We found a couple of bad things that needed to be fixed (an engine mounting bolt falling out and the secondary shaft nut completely loose...) and did some other maintenance that's been on the list. During the process of pulling out the engine, I sort of took a saws-all to the gigantic air box that has been plaguing me for over a year, so I'll be replacing it with pod filters. I also took the opportunity to paint the head cover and some other odds and ends and clean the frame, swingarm, and engine.
I have a bunch of stuff in the mail to finish up the project with - a head cover bolt I sheared off, pod filters, rejet kit, painting supplies, and The Spring. Hopefully I'll have some more updates soon!