Champion Spark Plug 71EZ-8PK EZ Start SE Plug with ECO-Core Carded, 8 Pack Fine wire electrodes concentrate spark energy for easier starting in all weather Booster gap delivers maximum voltage where it's needed most Projected core nose provides maximum fouling resistance for long, dependable life Replaces RC12YC, BKR5E &amp; BKR5EY Thread size: 14mm