Today I tackled the fork oil on the K75RT, and following a trend, it took me about half the time and a quarter the effort I'd expected. I'd last changed the fork oil on a K75 in 1996, and to be honest Brian Curry did most of the work. Having forgotten completely how to do it I consulted the IBMWR tech pages for a quick walkthrough as well as the correct amounts of fork oil for my bike (410cc each side). I then browsed a few enthusiast sites for tricks and tips and was immediately a bit dismayed over dire warnings over the challenge of getting the fill plug out without mangling the collar. I had a 17mm/19mm open end wrench so I thought I would pop the cap and see if I could loosen the fill plug on each side using the 17mm on the collar.
It was so easy I had no idea what the fuss was about. The wrench holds the collar just fine once you use the fill plug to turn the collar to where the wrench will have easy access, and the fill plugs loosened up and came right out. No marring, no issues at all, it was easy! On each side I set up a tin foil guard to protect the rotor with pieces of 16" by 12" foil and used a gladware container so I could inspect the old oil before transferring to my catch basin. The drain plugs came out and the fork oil drained, not the cleanest and definitely in need of a change. After it slowed to a dribble I removed the loosened fill plugs and let them drain for 10 minutes or so till they were empty.
I replaced the crush washers and then the drain plugs hand tight then just over a half turn with the wrench, then came the hardest part of the whole thing. I had an empty Mobil-1 gear oil bottle so I clipped the very tip of the pointy cap, poured in a little fork oil (Repsol 10wt.), shook it up and squeezed the oil into the catch basin. I measured 410cc with the trusty ratio-rite, refilled the gear oil bottle, put my finger over the tip and inserted it into the fill hole. I did spill a little bit here, a few cc's, then stood there and held it as it slowly filled the fork. After a while I rigged a water bottle to hold it, but it still took a good 20 minutes to empty into the fork with a few light squeezes to get the last bit. I was more careful with the other side, tilting the handlebar to get the best access to insert the pointy end (no spill) and having the water bottle at hand to hold it in place (instead of having to wait again for someone to jog by to stop and hand it to me.). I had new rubber orings for the fill plugs and it was as easy putting them back in as it was taking them out.
Buttoned everything up and took it for a test ride, subtle but noticeably pleasant difference. I remembered about 2-minutes into holding the gear oil bottle that I used to have a horse syringe/flavor injector, basically a comically large syringe with a large metal needle at the end about half as thick as the fill hole, that made this a 2-minute fill - maybe time to find another...
Anyway, like flushing the brake fluid and adjusting the clutch it turned out to be a truly simple job that is too often overlooked.
An aside, I also replaced the front caliper bolts with the $15 Motobins stainless steel bolt kit. The old ones were really hard to get in and out during the front pad change a few weeks back - the new ones are high quality and with the slightest bit of copper antisieze went in smoothly and tightened down beautifully. I will recheck for tightness after 100 miles or so.