The two plastic bits on the swing arm, one by the Yamaha symbol and the one underneath?
Looks likes its an automatic oil feed to lube the chain. It may have work ok. Pity we cant see how it was before partly removed.
Tweed heads Australia.
They are parts supplied by Scottoiler.
They are fixed to the swinging arm and guide an oil supply automatically to the chain/sprocket.
A bit OTT on a trail bike because they are prone to getting knocked off.
On a road bike they are ideal.
I fitted one on my Bandit 1200 in 2007 and only adjusted the chain 3 times in 12,600 miles - never changed the sprockets or chain yet.
Martyn
You're never too old to learn something stupid
East Budleigh. Devon