Rhythmic ticking or knocking outboard

[pophop]

Hey all, I'm new to the forums and need some advice. I have a 1996 mercury force 50hp it has been running great and on the way back to the dock, all of a sudden at full throttle the motor started making a funny tic or knocking the varied with rpm...long story short, it only does this when in gear and in water, works and sounds normal on muffs, compression good, gas mixture good, any help would be appreciated

 

[foodfisher]

Location of tick? Something may have vibrated loose near flywheel, may have picked up fishing gear near the prop.

 

[pophop]

I say a tic, more like a taping sound, sounds like it's under the cowl, in idle normal, soon as put in gear the noise starts, I have checked compression and fire, carb cleaned, I think it's in the foot area but not sure

 

[ZandoR]

If its in the LU you might have a worn out clutch dog or gear. Does it happen regardless of forward or reverse gear engagement?

 

[pophop]

More so in fwd..

 

[Jiggz]

Try conducting a test on the driveway with the LU in a large trash can full of water. With this set up you can actually place it in gear (DO NOT REV OR GO HIGH SPEED). Now try locating where the noise is coming from. Use a long screwdriver pressed against your ear or even better a mechanic's stethoscope.

 

[jerryjerry05]

Check the gear oil for metal.
Start looking for another lower unit.