Mercury 200 Noise at 3000 RPM

[LilSki]

I have been dealing with this noise on my 87 Merc 200 pretty much since I got the boat and I wanted to find out if it is normal or something I can get rid of. Above and below 3000 it is quiet and the only reason I hang out at this RPM range is in rough water and my friends boat cruises right at that speed around 30 MPH.

Things that have changed since I got the boat:
-Front airbox (silencer) from 97 175
-Mid section from 97 175
-Lower unit from 97 175
-One piece cover from 97 175
-Reed valves from carson reeds
-Solid aluminum motor mounts

None of these things have changed the sound in any way. I have a set of WMV carbs I will be installing soon but I don't think that would have any affect. The only thing I haven't changed yet is the prop. I am currently running a 24P trophy plus prop.

Here is a video of the noise. My phone doesn't really capture how loud it is but is resonates throughout the boat.

http://www.youtube.com/watch?v=FpeLlnXjJIw

If you think this is normal then that is fine I just wanted some opinions of it. If it is normal I may just re-prop it with a lower pitch so I can cruise at a slightly higher RPM. Then again re-proping might be the actual fix for it.

Thanks for any insight.

 

[ckmate225]

I pretty sure its normal, right around 3000 rpms there 2.4L mercs sound like thay are going to come apart. mine does the same thing. always has. and I have heard others complain about it as well, 2800-3200 seems to be where the harmonics are just right to make it sound like a cement mixer. I dont think you have anything to worry about.