2003 mercury 200hp carbed knocking

robaloroger

Petty Officer 2nd Class
Joined
Feb 16, 2010
Messages
123
I was coming in from fishing and when I was coming off plane I heard a knocking. Idled in to the dock for about 5 mins and still heard the knock. As I was docking and put it into neutral the noise went away. Got home checked compression all 6 are 120lbs. Checked for play in the pistons through the spark plug hole and there was no play. Ran the motor on the hose and there is no noise in forward neutral and reverse. One thing I did notice the last 2 times out I heard a low noise that would increase with rpms. It sounded similar to a truck with mud tires driving on pavement. I am thinking bearings maybe. I was going to take the boat to the ramp to see if it makes the noise under load. any info or thoughts would be greatly appreciated.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: 2003 mercury 200hp carbed knocking

Check your lower unit oil for water and metal debris as you could have chipped a tooth on pinion...
 

robaloroger

Petty Officer 2nd Class
Joined
Feb 16, 2010
Messages
123
Re: 2003 mercury 200hp carbed knocking

Check your lower unit oil for water and metal debris as you could have chipped a tooth on pinion...

I will check tomorrow. I was hoping it was in the LU and not the powerhead. I have 2 spare LUs. Thanks
 
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