I previously removed the clutch, flywheel and rear main seal so I can replace the crankshaft rear main seal, the flywheel o-ring and the oil pump cover o-ring. You can see how I did that work here:
The inside of the bell housing as well as the shelf under the transmission showed oil leaks, so one, or all, of these are the likely culprits.
Grunge Inside the Bell Housing Suggests O-rings and/or Rear Main Seal Leaks
Oil & Grudge On The Shelf Under The Transmission
When I opened up the oil pump to take measurements and do a visual inspection, I decided that I had to replace the oil pump due to a lot of wear and tear to the rotors inside the pump. You can see how I removed and measured the oil pump here:
Scratches On Lobe of Oil Pump Inner Rotor
Grooves on Face of Oil Pump Outer Rotor
When I first got the bike, in debugging a low oil pressure light that came on, I discovered that the oil filter high pressure bypass valve was hanging by a thread. So, unfiltered oil was circulating, but I didn’t know for how long. Based on the condition of the oil pump and the scores I found in the rod bearings, I think unfiltered oil circulated for while. Not what I wanted, but I’m glad I took a look at the pump.
You can read about how I did the work here:
And, you can see a short video that summarizes the work here:
Due to what I found with the oil pump, I’m making a detour on the project. I’m going to pull the crankshaft to inspect the main bearings. I suspect I won’t like what I find there either, but it makes sense to take a look.