Mercury Mariner Service Manual 6, 8, 9.9 210CC Sailpower, Page 48Get this manual
Carburetor Adjustments INITIAL STARTING ADJUSTMENT If motor cannot be startedturn low speed mixture screw slowly inward (clockwise) until it seats lightly, then back out 1Y2 turns(Turning mixture screw in tight will damage needle and seat This approximate setting will permit startingAs soon as motor starts, allow for warmup (run for several minutes)throttle engine back to idle for about one minute to allow RPM to stabilize, then make final adjustmentsLOW SPEED MIXTURE ADJUSTMENT 1Start engine and allow to warm up (run for several minutes)Throttle engine back to idlefor about one minute to allow RPM to stabilize2With motor running at idling speed while in forward gear, turn low speed mixture screw counterclockwise until motor starts to "load up" or fire unevenly from over-rich mixture3Slowly turn low speed mixture screw clockwise until cylinders fire evenly and motor picks up speed4Continue turning mixture screw clockwise until too lean mixture is obtained and motor slows down and misfires5Set low speed mixture screw halfway between rich and lean 6Do not adjust leaner than necessary to attain reasonably smooth idlingWhen in doubt, set mixture slightly rich rather than too lean7Check for freedom from cycling between idle and 2000.RPM (in forward gear)