Fuel Pump O-Ring

[mcyoungy]

I'd say that's a big o-ring and maybe not standard fare at a motor factors.

http://www.yamahamotorcyclespares.co.uk/...TANK&uID=0

item 12 I guess

Personally, I'd re-use the old one anf if it doesn't leak, all's well.......... but it's not my bike.