1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 147Get this manual
EMISSIONS
CERTIFICATION LABEL: The certification label must be placed on each engine at the time of manufacture and must be replaced in the same location if damaged or removedShown below is typical certification label and is not representative of any one modelLabel shown below is not to scale; (shown at twice the normal size)
Emission Control Information
This engine conforms to 1999 Model Year U.SEPA regulations for marine SI enginesRefer to Owners Manual for required maintenanceFamily: WM9XM.747220
PART37855211 22
Idle Speed (in gear): 850 RPM Timing: Not Adjustable Standard Spark Plug: NGK DPR6EA-9 Gap: .035 Valve Clearance (Cold) mm Intake: 0.15-0.25 Exhaust: 0.20-0.30