Thanks Geekventure! I was sort of leaning towards that. Only because I couldn't see anything else wrong with it. No worries about running it now as the engine is out and at the shop for repairs. I will call them today and confirm that they checked the Main Shaft Bearing. (I would hope they would!) There were lots of other issues in addition to that noise. Thanks again! Hopefully, I will get the engine back and it will be in good running condition for a while!
Originally Posted by Geekventure
I live in SF and I've worked on both a 97/98 Adventure 620 EGS-E (the first one with the dual low-mounted pipes),
as well as, the blue and orange 99/2000 Adventure R my friend use to own.
Just from your description and knowing the engine...it sound to me like you might have the bearings from the main shaft bearing dancing around in there.
This bearing is known to lose it outer race that hold the bearing in and when it does go the bearing themselves are free to reek havoc!
Don't ride it or run it very long.
Just check that bearing first by pulling the clutch plate and stator...etc
I only lost the race on my 620 LC4, but I kept going and the block actually cracked, destroying the engine!