1971 Johnson 125HP outboards Service Manual, Page 62Get this manual
REASSEMBLY OF POWER HEAD TO EXHAUST HOUSING
a' Make sure gasket surfaces of power head and power head adapter are cleanPlace new gasket in position on the power head adapterInstall new "0" ring on crankshaft and lightly lubricate spline with Type "A" grease
bPlace power head on exhaust housing adapter, using care to avoid damage to splined ends of crankshaft and driveshaft00 NOT in any case cause the driveshaft to be rotated counterclockwise, as the water pump impeller vanes may be damaged3