The Yamaha REPAIR KIT 1 has thirty products enlisted in the schematic.
The most reasonably priced component used on the 90trr (90tlrr) 1993 Repair Kit 1 is the Gasket (663) (nas).
Some items from this specific schematic: Gasket, Valve Seat (nas), O-ring (655), Carburetor Repair Kit, Ring, O(663).