Yeah leave it be man, I have a 1990 650sx stand up jet ski all stock down to the oil injection system, no problems! Every one says they go out It hasn't in 24 years , my dad bought it new so I know it's original , also have a 2001 yamaha blaster an all stock with the injection system too an no problems, the only upgrade to delete the pump is u can gain a lil hp with pre mix but it ain't much.