Have a 1996 Murcury Force 120hp. Hearing a load knocking noise from the lower unit while moving forward. Do NOT hear the knocking noise while in Neutral or Reverse.
More than likely the clutch dog's worn.
Possible the linkage or cable needs adjustment(hope this is it).
Take the shift linkage off and shift by hand.
If it does it then the lower needs to be taken apart.
Post pics of the dog(both sides) when you get it out.
The 97 with OEM doesn't have a washer on the nut side.
If he's missing the thrust hub he'd be chewing up the lower and doing lots of grinding(probably wouldn't hear it as it's under water)
More than likely the clutch dog's worn.
Possible the linkage or cable needs adjustment(hope this is it).
Take the shift linkage off and shift by hand.
If it does it then the lower needs to be taken apart.
Post pics of the dog(both sides) when you get it out.
The 97 with OEM doesn't have a washer on the nut side.
If he's missing the thrust hub he'd be chewing up the lower and doing lots of grinding(probably wouldn't hear it as it's under water)
The only difference between reverse and neutral is which clutch dog engages. Since there is no noise in reverse, it tells you the forward dogs are either worn out or not fully engaging due to misadjusted linkage.