Honda 15 hopping in reverse

[Jelwell1982]

I have a pair of Honda 15 outboards in my custom built Catamaran.
My port motor is hopping around whenever I put it in reverse.
It gets more and more violent as it throttles up.
mounts and brackets are all secure exactly like the starboard motor.
It appears to be staying in gear so I was thinking maybe the power trim hydraulic fluid, but it is topped off and seems ok.

Open to suggestions!
Here is a video:

Thanks for the help!!

 

[jgmo]

I think it IS your power trim. If you can reach down and lift or push the gearbox away from the hull by hand, then the tilt isn't holding.

The first thing to check, if this is the case, would be the MANUAL VALVE. If it is not tightly closed, this can happen.

If you find the manual valve tightly seated, then the trim/tilt will need service as there is likely a stuck check valve allowing this to happen.

Good luck.