70 hp mercury 3 cyl,knocking after hard hit lower end or powerhead?
as described merc 70 3 cyl knocking after hitting concrete mooring 3/4 throttle,bent stainless prop ear in half.took apart lower end and shaft straight.knocking only at 1/2 to 3/4 throttle.im mechanic by trade so can take it apart easily.any help as where to start looking would be appreciated.measured the stroke of the 3 cylinders 2 came up short 30 thousands compared to the others. g.w.fitzgerald@worldnet.att.net
Re: 70 hp mercury 3 cyl,knocking after hard hit lower end or powerhead?
Sounds like that motor Stopped quite Suddenly.... probably bent the crank, rods,???? sounds like you have little left to rebuild, Junk it,+ find another motor...
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Re: 70 hp mercury 3 cyl,knocking after hard hit lower end or powerhead?
bigdaddy,When the prop stops suddenly, the flywheel (which has a heavy mass/weight) tries to keep turning. I'll bet a dollar to a doughnut that your crankshaft is cracked at the first throw underneath the flywheel.Almost for certain the crankshaft is bent.If you even think about repairs make sure you magna-flux the crankshaft and rods.My two cents, Good LuckGold Bear
70 hp mercury 3 cyl,knocking after hard hit lower end or powerhead?
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