60 Hp Mercury knocking

Mtx1

Recruit
Joined
Sep 27, 2021
Messages
1
Hey guys my first post here hopefully I'm not too far over my head. I have been lurking a few weeks now but finally have a problem I can't seem to pinpoint. Just bought a 93 Skeeter sd 80 with a 60 hp mercury on the back. This is my first boat so I did lots of research. After reading a bunch of info online I realized how bad the transoms get in some of these boats so that was my main concern when purchasing. Well transom was in great shape this boat is in great condition for the year. Except it seems like it has a knock or a loud tick that follows engine rpm. I didn't notice it on the muffs but when I took it out on the lake I can hear it very easily. So this knock comes on at idle you can hear it even before the engine fires. It goes away at 3k and over or if I throttle hard at low speeds. It happens in all gears and neutral. It ran great all weekend with my kids but want to make sure it's good before I take it out again.
So I read up on this issue and this is what I tried so far. Brought pistons to TDC and around that area, push on pistons and don't have any movement anywhere on each stroke. I pulled each plug 1 at a time and the noise stays the same when cranking. I pulled the prop and same issue. Pulled the lower today and fire it up for a few seconds, same noise with lower removed completely. So it's gotta be in the powerhead I'm guessing.
What else could I try to know what the issue is? I work on cars and Harleys so don't mind getting my hands dirty just don't know where to look from here.
Over the weekend we ran 15 gallons through it and the knock didn't get any louder.
Thanks for any help!
 

pointblank1000

Petty Officer 2nd Class
Joined
Jan 17, 2011
Messages
139
I would check the compression before moving on.
Did the previous owner rebuild it?
It could be anybody's guess.
 
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