1993 Johnson Evinrude "ET" 9.9 thru 30 Service Manual, P/N 508282, Page 39Get this manual
7Inspect propeller shaft seals for evidence of leakageReplace if necessary8Drain and refill gearcaseLubricate all components of engineSee Lubrication, this section9Check propeller conditionReplace 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 Tunerfollowing directions on canDO NOT allow tuner to soak in engine more than one hourDuring engine operation, carbon can build up on internal powerhead components, eventually causing piston rings to "stick Adding OMC Carbon GuardTM fuel additive to every tank of fuel is your best protection against such buildup and the resulting mechanical problemsIf Carbon Guard is not used consistently in the fuel, OMC Engine Tuner should be applied every 50 operating hours13Check engine operation by verifying minimum test propeller RPMRefer to Engine Specifications, this Section it 14Momentarily pressurize fuel system and check for leaks15If engine is to be stored, refer to Off-Season Storage, this section