1978 Evinrude Outboards 9.9/15HP Service Manual, Page 55Get this manual
CONNECTING RODS The connecting rods provide linkage between the piston and crankshaftConnecting rod bearings include roller bearing at the wrist pin, and split cage roller bearing at the crankshaftThe crankshaft is of the two-throw type and is supported by three main bearingsA single row roller bearing is at the upper journalA split cage roller bearing at the center journal is aligned to the cylinder block by dowel pinA ball bearing at the bottom journal absorbs the radial and vertical thrust loads of the crankshaftCOOLING SYSTEM Water for engine cooling is supplied by two-stage pump containing rubber impellerAt low speeds, the pump operates as full displacement pumpAt higher speeds, the impeller blades bend back under the increased water pressure and the pump becomes centrifugal action pumpREFERENCE PICTURE THERMOSTAT SEAL SEAL LIP FACES DOWN
CHECKING MOTOR TEMPERATURE
The Markal Thermomelt Stik, heat sensitive stick similar to crayon which melts on contact with surface at specific temperature, is used to measure power head temperatureThe motor is best checked when operating on boatIf this is not pOSSible, run the motor in test tank for at least five minutes, at maximum speed of 3000 rpm (AND MINIMUM OF 1500 rpm)Mark the surface to be checked with the StikThe mark will appear dull and chalkyWhen the surface temperature reaches the temperature rating of the Stik, the mark will melt, becoming liquid and glossy in appearanceOn some painted surfaces on which the Stik will not leave mark, it will be necessary to hold the Stik against the surfaceSee Figure 5-3