Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 29Get this manual
RPM Limiter Troubleshooting The speed lim ite is desig ned to reduce ignition voltage to cylinders 2,4 and when eng ine RPM exceeds
6000200 1If engine ign ition appears to be intermittent at an RPM of less than 6000, disconnect the BLKYEL LEAD from the lower switch box whic goes to he RPM limiter
CONTI NUITY
Refer to ENGINE WIRIN DIAGRAM SEC 20If engine then runs properly, replace RPM limiter211 eng ine igniti on abruptly shuts off to all six cyl inders at 6000 RPMtest di ode It may be SHO RTED Refer to DIODE TEST IN G, following 3When ignition key is turned to the "OFF" positionand the eng ine cont inues to run on cyli nders, test the diodeIt may be open or di sconnected