Unusual sound during deceleration

[J Baron]

" My new (used) 1999 9

" My new (used) 1999 90HP Johnson makes an unusual sound when I decelerate. It sounds like someone shaking a coffee can with marbles inside. If I retard the throttle slowly, it is much less noticeable and goes away if I either power up again or come to rest at idle. The quicker I retard the throttle the more pronounced this noise is. Other than that the engine runs great. Any ideas? "

 

[Pat S]

I have 2001 90 hp on my flats

I have 2001 90 hp on my flats boat and it makes the same noise. I have been running the boat for a long time with no problems.

 

[sparky]

Reed valve noise.

Reed valve noise.