1988 mercury 115hp clacking noise

Lk40hp

Petty Officer 3rd Class
Joined
Aug 22, 2012
Messages
84
Like the title says I have a 115 tower of power. It is a little tough to get started and when it does start there is a clacking noise. When you rev it up it goes away, and when its warm its not as bad at an idle but still bad. It will kill the motor when its cold, so you have to rev it up and then quick put it in gear... what is it??? Also it isn't like a backfire or a cough like a johnson, and its not quite like a rod knock. The best way to describe it is it is a clacking sound... sounds like metal, but yet it goes away when revved up.
 

Iceman66

Petty Officer 2nd Class
Joined
Jun 30, 2008
Messages
199
Re: 1988 mercury 115hp clacking noise

Take out the sparkplugs,turn the flywheel with just a thiny movement in both directions,
do this in all sectors and feel for backlash.

Remember!!! Dont turn it more than just a thiny bit unclockwise(impeller issue).
When going trough the sectors,turn clockwise.

Could be a rod knock or a bad piston pin.
It doesnt go away when revved up,just more difficult to hear it.

Sure you dont have changed timing? ("picking" noise)
 
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