1985 mariner knocking but not when idleing

[jonharper17]

the boat idles fine but when you put it into gear it starts knocking sounds like its coming through the lower unit can you give me any advice

 

[This_lil_fishy]

Re: 1985 mariner knocking but not when idleing

Wrong section, but probably a lower crank bearing if I had to guess. Noisy under load. I had a car with a bad crank bearing, it would have a barely audible knock until you put it in gear or gave it some guess. I'm no mechanic though...

Ian

 

[CharlieB]

Re: 1985 mariner knocking but not when idleing

Does the noise occur in both Forward and Reverse?

If the shift cable has stretched it may not be locking fully into Forward.

Remove the spark plugs so that the motor cannot start.

Shift into Forward gear and step on the prop turning it CCW and make the engine turn.

Does the motor turn completely with the prop or is there any 'ratcheting as if the engagement dogs are jumping in and out?

If so then try disconnecting the shift cable, manually shift it into Forward gear and retest.

If it fully locks into gear now then replace the shift cable.