The early FXR's had an enclosed chain rear drive. The rear sprocket is enclosed in an aluminum housing. Then there are rubber boots that connect the sprocket housing to the primary. The chain runs in an oil bath. This was actually a very good design and the chains last forever. There are a couple draw backs though. The system leaked (what a surprise), and changing the rear tire is a 5 hour job. The one on this bike doesn't seem to leak (that was a real surprise).
As mentioned in an earlier post I am upgrading the primary, transmission and swingarm. The new setup wont support the enclosed chain system. It will be replaced with a rear belt drive.
Here's a picture of the enclosed system.
The engine has 57,000 miles on it. It is surprisingly clean and unmolested. It still retains the stock carb. The exhaust bolts don't appear to be stripped of damaged. Even the original pop rivets still hold the timing cover on.