spark plugs

[Danny chavis]

took out spark plugs 1991/90hp yam tlrp.plug look good around the gap/ground electrone,accept they had a thin black oil film on them. got a yamaha service manual - seloc manual on order. are these plugs normal? if not, where should I start to look for and do to solve this problem. thanks everyone. Danny

[boats.net]

The engine is burning gas and oil mix so seeing oil on plugs is not uncommon.