2005 Mercury 50ELPTO - noisier at certain RPM

[Joseph10]

All,
I was hoping that someone could help me. I took out the used 2005 tracker PT175 I bought which has a 2005 Mercury 50HP outboard.

I did have the engine compression checked by a dealer before purchasing (124-126psi all three cylinders).

The prop did have a ding that I had repaired before I took the boat out. The boat planes out very quick and turns about 5200rpm at 32mph with 2 adults and a full tank of gas (seems to perform about like I expected).

Here is my problem. It seems that right around 4200-4300 RPM the motor gets louder (sounds like it is working much harder or something). The trim position does not affect this. It seems very specific to this rpm range. It goes away at any other RPM. Other than this, the engine seems to run good and sounds like a normal/healthy outboard.

Is there anything to be concerned about here? Is this indicative of any specific problem?

Thanks in advance for any help/comments.

Thanks,
Joseph

 

[GregLS]

Re: 2005 Mercury 50ELPTO - noisier at certain RPM

I have a 1998 Mercury 50 ELPTO that I've had since it was new. It has the exact same thing you describe with being louder at one RPM. It has always been like this from the beginning and I never worried about it - runs fine otherwise. I would say it is likely something to do with the design and your motor is fine.

Greg

 

[Joseph10]

Re: 2005 Mercury 50ELPTO - noisier at certain RPM

Thanks for the reply. I feel better now knowing that someone else observed the same thing. The boat seems to run great - I guess I need to stop overanalyzing....

Thanks,
Joseph

 

[gjblanchard]

Re: 2005 Mercury 50ELPTO - noisier at certain RPM

For what it's worth, I've got a 2007 Mercury 50 ELPTO that does the same thing, with high noise in a specific RPM region. It runs great and I don't worry about it. On my boat (a 16.5 ft. deep V) I have found that a 10 1/2 x 13 (large blade) prop is just right and tends to keep excess noise down too.

 

[Joseph10]

Re: 2005 Mercury 50ELPTO - noisier at certain RPM

Thanks for the reply. Looks like this must be the norm for this motor. Maybe it is some sort of resonance thing with the way it is designed.

Joseph

 

[tcoward]

Re: 2005 Mercury 50ELPTO - noisier at certain RPM

I have a 2005 50 ELPTO on a Tracker Pro V16 and it too has a loud noise while running at 4200-4400 rpm.. You detect it as the motor speeds up or slows down when it passing through that RPM range. Very noticable while trying to cruise at it... The noise makes me avoid cruising at that range... It has been that way since new. I recently had the motor checked out at the dealer and everything was fine. Compression, timing, etc. Other than that noise, the motor is very dependable and runs great... Lots of power and planes the deep v hull quickly. I pay attention to engine noises, however this one might be best left alone. Appreciate everyone's comments.

 

[Trad]

Re: 2005 Mercury 50ELPTO - noisier at certain RPM

I just bought a 2006 Monark boat with a 50hp ELPTO Mercury outboard. I too have the same issue. I got the boat and never really notced the noise issue. I then bought a new Michigan Wheel Vortec prop (with the separate hub and plastic insert). The sound was terrible! I changed back to the original OEM Quicksilver prop (1 piece) and the noise went way down. I'm not sure what the issue is here but the OEM prop reduced the noise volume. Any help solving this problem would be greatly appreciated! The engine runs great with lots of power but the noise issue is concerning.

All,
I was hoping that someone could help me. I took out the used 2005 tracker PT175 I bought which has a 2005 Mercury 50HP outboard.

I did have the engine compression checked by a dealer before purchasing (124-126psi all three cylinders).

The prop did have a ding that I had repaired before I took the boat out. The boat planes out very quick and turns about 5200rpm at 32mph with 2 adults and a full tank of gas (seems to perform about like I expected).

Here is my problem. It seems that right around 4200-4300 RPM the motor gets louder (sounds like it is working much harder or something). The trim position does not affect this. It seems very specific to this rpm range. It goes away at any other RPM. Other than this, the engine seems to run good and sounds like a normal/healthy outboard.

Is there anything to be concerned about here? Is this indicative of any specific problem?

Thanks in advance for any help/comments.

Thanks,
Joseph