Re: 78 merc 1150 question
To verify the timing on that motor, you need to verify the timing pointer is set accurately. Remove the spark plugs, and set the #1 piston to TDC using a screwdrived thru the plug hole. Nowmeasure from the plug hole to the piston crown with an accurate ruler. Add .464 inches to that measurement, and back the piston down 2 in or so. Now turn the flywheel until the piston crown is at the exact spot you calculated. The timiong pointer should read .464 BTDC on the timing decal. If not adjust it until it does. Now set the motot to TDC and look at the dissy pully. Remove the pully cover and see where the cast arrow is pointing. It should point at the punch mark on the flywheel.
