ORESU-61-78-004 C. 2
Outboard motor Marine recreation maintenance tips ClilCilflipygy~l Qggr@] g . t by PeterL. Hendricks Adapted,by permission,from 8asic Outboard engines Hawaii County Agent OtstboafdMotor Maintenance,published Most outboards,given proper care, by the Universityof Hawaii SeaGrant require little serviceother than periodic Universityof Hawaii CollegeProgram, August I977 UNIHI. maintenanceand adjustment.The SeaGrant CollegeProgram SEAGRANT-AB-774i3 !. individualengine owner can handle mostof the periodicmaintenance. This bulletin was written to aid the individual in basic outboard maintenance skills. Mostof theprocedures are possible withoutspecial tools. If youare in doubt aboutyour motor's service, consult a dealer or, in minor cases,the factory- authorizedowner's manual for your Power particular engine, head Power source Thepower source for all outboard motors is the internal combustion, reciprocatingengine seefigure I!. The basic differencein thesepower sourcesis the way in whichthe fuel mixtureis ignited.Most outboards have their fuel ignitedby anelectric spark Otto Cycle er pump Engine!,as opposed to heat-of- ck vent compressionignition DieselCycle!. In mostoutboards, one complete crankshaftrevolution completesthe aust column seriesof eventsnecessary to makethe enginerun. This is calleda ttco-stroke er pump cycle. In a two-strokecycle engine,five itation eventsmust take place in two strokesof thepiston, or in onerevolution of the e crankshaft.They are: I! intake fuel and air!, ! compression, ! ignition, ! power,and ! exhaust.A compressedfuel chargeis fired each time the pistonreaches the top of the cylinde, andeach downward stroke is a powerstroke. In orderto accomplishthis, the initial pressureof theincoming fuel-air Lower mixturemust be raisedto a point ~ anat gnmewhathie'her than the lowest othervAe,a freshcharge of fuel could
Figure] .~utetcay dfetotngof typicalinternal combustion, reciprocating outboard engine Otto Cycle!, Oregon State University ExtensionMarine Advisory Prograsn A Land Grant / Sea Grant Cooperative SG 43 September 1978 not be admitted and the enginewould Periodic servicing 5. Lubricateall greasefittuigs, using not ruii. This elevationof pressure Many of the troublesrelated to manufacturer's recornrnended requiresthe useof an air pump, or outboard motors will bc much easier to lubricant, compressor,of approxiinatclythe same repair if caughtbefore they do extensive 6. Check remote control box, cables, volumeas the cylinder itself. damage,Sometimes the lack of proper and wiring harness, Shift lever Coincidentallv, such an air pump is serviciiig is thc primary causeof failnre. shouldmove through full rangefrom available ivith a minin»mi of additional The following list of proceduresmay rcvcrse to forward, Throttle lever parts, cost,or fricti<>nallosses bv help in a regiilarprogram of preventive shouklmove smoothly from low idle utilizing thc opp<>siteside of the pist<>n maintenance for your outboard. to full open.Lubricate exposed and cylinder asthe' pump. Suchengines, Pr