Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 62Get this manual
Idle RPM ADJUSTMENT .Q.CAUTION
Engine Idle RPM must NEVER exceed 750 RPM In gear1With engine in water, con nect electrical harness and fuel line to engineStart eng ine and allow to warm up
2With throttle cable barrel removed from barrel retainer, adjust primary pickup timing screw (ato obtain specified idle RPM (650-700) with the engine running in forward gearRetighten nut (b) on adjustment screw3With end of th rottle cable connected to throttle lever, hold hrottle lever against idle stopAdju st
throttle cable barrel to slip in to ba rrel retainer on cab le anchor bracket with very tig ht preload of throttle lever agai nst idle stop Lock barrel in place4Check preload on throttle cable by placing thin