Parts such as the Fuel Tank: O-ring, Hose, Hose (l235), Lever, Cock are included in the Yfp350u 1988 Terrapro Fuel Tank parts fiche.
The most reasonably priced component used on the Yfp350u 1988 Terrapro Fuel Tank is the Washer(6a1).
On this parts fiche the Screw, Pan Head (j10) is the most specified component.