I just got back from Manzanita, OR for the WSBMWR Rain Run. I put about 800 miles over four days on the 2004 bike with the Dymag wheels and Ohlins suspension. Those made a huge improvement. So far the transplants are doing their job.
Here are photos of the gizmo:
It is, as sgoodwin figured, a cover for the throttlebody.
I discovered a couple of items while doing the wheel transplant. First, I knew that the wheels between the early abs bikes and the later ones differed in the posts for mounting the abs ring. No problem, I just transferred the rings. Oops, that screwed the offset up. If I'd left things as they were, I would have been fine. So back to original configuration. All would have been good except that I wanted the fancy wavy discs that came with the donor bike. I left those on the Dymag wheels and put them on the 04 donee bike. No problem, I thought. Putting the 04 wheels with stock discs on the donor bike was a different story. I just could not get the calipers to go on. Come to find out, the early bikes had 305mm discs and the later bikes have 320. So no fancy wavy rotors for me.
The donor bike came with an after market Wunderlich seat. The little I rode that bike, the seat seemed fine. After another 800 miles on the stock seat, I was really, really ready for something else. I ordered a pair of adapter pins from Sargent and installed the Wunderlich on the 04. I'll give a report after I ride it a bit.
The suspension - The Ohlins are great. The Nestucca River Road has some pavement patches and slide repairs. It makes for interesting riding. The Ohlins soaked it all up.I have noticed, however, that I can now flat-foot at stops. That's nice at stops but detracts from ground clearance, so the Ohlins rear must be shorter. The donor has a short shaft strut, so I'll move that over and see what happens.
The Dymags need refinishing. Any suggestions?