'94 Mercury 40hp making knocking noise....please help!

[Gigemaggie]

Hey guys need some help! Just bought a 17ft duck boat with a 1994 Mercury 40hp tiller. When I test drove it ran perfect no issues. A buddy and myself installed a hydraulic jack plate to the boat last week and took the boat out later that day. As soon as we started idling away from the ramp the motor was making a lknocking noise, almost like we were hitting a log or something. We figured out the motor must have been trying to shift back into neutral because if i put a little pressure on the shift lever it would solve the knocking noise and run awesome. I didn't have to constantly hold pressure but would at first when shifting into forward. Was hoping this is not a clutch dog issue, hoping its just the lever and/linkage but could not figure out how to adjust. It did not make this noise in neutral or reverse. There is quite a bit of play in the lever.....any ideas?

 

[Gigemaggie]

Bump for help

 

[hemi rt]

When you put the jack plate on you may have changed the shifter cable length. Check that it is adjusted properly.

 

[Gigemaggie]

Thanks! I am assuming I need to tighten cable. Seems like the only way to get to it is by removing the throttle body. How do I tighten once I can access? Sorry not very mechanically inclined!

 

[Gigemaggie]

I think I got her figured out. Found the spot near lower unit to adjust cable. Tightened it up a bit....hopefully this solves it