1985 Force Reverse starts to knock when using

[thapharm]

I have put a bunch of work into the engine and everything was working fine until I put it on the water. So when I put it in reverse it is spinning and working fine, but when I throttle it so I can actually start moving in reverse in starts like knocking and shaking the whole boat. Anyone have any ideas?

 

[Jiggz]

It sounds like slipping dogs. but you need to get behind the motor, listen and feel the source of the knocking. Put your hand on the motor leg to locate the source of the knocking. The shaking is the after effect of the clutch dog engaging and disengaging.

If you verify it is the clutch dog slipping, adjust the bottom shift rod, a little bit at a time. Or you can also do the adjustment at the shifter adjustment located under the bottom carb. The goal is to center the shifter between forward and reverse.

 

[thapharm]

Now that you say this it started after we adjusted the throttle rod on the roller to make it open the butteflys on the car more. Where is exactly the bottom shift rod? Sorry I am newer at these engines