Step by Step Valve Clearance Check/Adjustment using the Haynes Service manual.

REPLACMENT PARTS:

Retainers;
Gas Tank- RETAINER (17585-MEW-920) X 1
Airbox- RETAINER (BLUE GREEN) (TOKAI) (17711-S0X-931) X 1

If camshafts/cam chain tensioner is removed...
GASKET, PLUG HOLE (12395-MBW-003) X 4
WASHER, SEALING (6.5MM) (90463-ML7-000) X 8
GASKET, TENSIONER HOLE (14523-MCW-003) X 1
WASHER, SEALING (6MM) (90442-397-000) X 1

I would recommend getting OEM parts through Revzilla, they always seem to have the best prices...