1988 Johnson/Evinrude "CC" 40 thru 55 Models Service Manual, Page 69Get this manual
Trouble Check Chart (Cont TROUBLE 3LOSS OF POWER (Providing Ignition OK) (Cont) POSSI BLE CAUSE EOVERHEATING POWERHEADSee Section Thermostats damaged Thermo cover or gaskets damaged Pressure control val ve damaged Exhaust cover gaskets Ieaki ng Head gaskets leaking (warped head) (water in cyl inders) Water intakes obstructed Pump housi ng ai bl eed restri cted Water passages obstructed Pump plate not sealing (bottom) Pump impel Ier damaged Motor too high on transom Pump housing distorted (overheating) Pump housing cover seal worn (driveshaft grooved) Water tube grommet damaged FGEARCASESee Section Propeller hub slipping Bent or worn propel Ier Bent gear housing or exhaust housing Incorrect propel er ASPARK PLUGSSee Section Cover or inner terminal damaged (terminal point out of H.Tlead)Fau Ity Ieads or crossed leads Loose spark plugs (low torque) Defective spark plugs (cracked insulator) Incorrect spark plugs BIGNITIONSee Section Incorrect timingLoose wiring (connectors improperly joined) Coils damaged Arcing around ignition coils Loose connect ions to sensor coi Is, charge coils, ignition coils, or on power pack ground lead Leads groundi ng out on sensor coi Is, charge coils, ignition coils, or key swi tch Sensor coils Charge coi Is Power packs Arcing in key switch CFUEL SYSTEMSee Section Recirculation hose plugged or pinched Recirculation nipple plugged Recirculation check valve stuck open Recirculation hose not routed correctly causing restriction Mani fol check valve pi ugged or restri cted Carburetor idle system has foreign particles in passages Prime valve seat has foreign particles on seat and will not shut offCarburetor fI oodi ng Fuel pump diaphragm leaking into crankcase Primer bulb check valve not operating SYNCHRONIZATION AND LINKAGE ADJUSTMENTSSee Section Throttle plate synchronization andor throttle cam pickup ncorrectl set Engine idle speed set too low Check these items if engine stalls