Honda BF50 efi lower unit noise/ vibration

[RJ9]

Hello i put my outboard in forward gear with just the muffs on and when i reduced throttle there was a strange noise and vibration that only went away when i put it in neutral, i cannot replicate noise with outboard in water, should i be concerned or just leave it alone?

 

[jgmo]

Hi,

First, I would highly suggest that you not do this with the prop on. It is so dangerous and, even when you think "I've got this" something can distract you and life is altered INSTANTLY.
Ok. soap box back in closet... ....temporarily.

I honestly don't know what's up there but will venture a guess.

If you are doing this with the prop on, it could be pushing enough air that it's bouncing off of a badly worn thrust washer. The air being much less dense than water might allow that to happen. Not sure...just a theory.

If there's something causing the prop to be unbalanced....like a hub bushing starting to fail, or a slightly bent/worn blade that might cause something like this too.

Since fishing line wrap on the propshaft is the #1.killer of the seal AND a worn thrust washer should always be replaced to prevent housing damage, I suggest that you remove the prop and carefully inspect it and the washer. ANY scoring of the thrust washer indicates replacement is necessary..

Even if you don't SEE any issues with the hub bushing, match mark the inner and outer portions before running in water so that you will be able to detect any movement there.

While bent or nicked blades can be repaired and the prop re-balanced, it's often easier and cheaper to just replace unless you know of a shop that still does that work anymore.

Run it while the prop is off to see if the condition has changed or not.

Good luck

 

[William01]

Something vibrating in the boat or the trailer itself vibrating, off the trailer on the lake the vibration is gone. Kind of like when my wife tells me there’s a strange noise coming from her vehicle, I clean out all the treasures in the console, glove box, door pockets and any other bits and pieces laying around… weird noise is gone.