1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 35Get this manual
7Inspect propeller shaft seals for evidence of leakageReplace if necessary8Drain and refill gearcaseLubricate all components of engineSee Lubrication, this section 9Check propeller condition Replace if damaged10Retorque all screws and nuts to specifications11Run engine in test tank with correct test propellerCheck cooling system operation12To remove carbon deposits from combustion chambers and pistons, inject OMC Engine TunerTM following directions on canDO NOT allow tuner to soak in engine more than one hourUnusual operating conditions, quality of fuel, or use of non-recommended oil can accelerate the formation of carbon depositsStep 12 should be repeated every 100 operating hours or once each season, whichever is more frequent