1985 Mercury Outboard V-300 V-3.4L Shop Service Manual, Page 111Get this manual
Crankshaft I Ins pect crankshaft 10 dri ve shaft spli nes for wear(Replace cra nkshaftif necessary 2Check cran kshaft for straigh ness(Heplace as necessa ry,) 3Inspect crankshaft oil seal surfacesSealing surfa ces mu st not be grool'ed, pit led or scral chc(l (Replace as ncccsstl ,J Check all crankshaft bearing urfaces for Tu stwaWr mark s, hatter mark suneve wear andor o'crhealing(Refer 10 "Connecting Hods" 11 page 4.27 5If necessar y, clean crankshaft surfaces with crocus clot h
as shown
AWARNING
DO NOT spin-dry crankshalt ball bearing with compressed air
6Th oro ughl clean (with solve ntand dr crankshaft and crankshaft ball bearingRec heck urfaces of cran kshaftReplace rankshaftif surfaces cannol be properly "cleaned up"If crank shaft will be re used, lubrica te sur faces of crankshaft with light oi to prevc nt rustDO NOT lubricate cran kshaft ball bearing at th is time