Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 68Get this manual
4 Move throttle lever to wide-open-throttle (W.O.T position and adjust full throttle stop screw to allow full throttle shutter opening at W.O.TVerify that throttle shutters do not act as throttle stopAllow 0.01 in0.015 in(0.25mm0.38mm) clearance between roller and throttle cam at W.O.TRetighten jam nut on adjustment screw
Timing Adjustments
Throttle Position Indicator (TPI) Adjustment for Idle Timing
IMPORTANT: TPI can only be adjusted using digital meterAnalog (needle) type can cause damage to TPI
TPI ADJUSTMENT USING DIGITAL VOLTMETER
1Disconnect TPI from ignition harness
aFull Throttle Stop Screw RollerThrottle Cam