2008 Mercury 225 Pro XS

[basscatbat]

Maybe somebody can help with some questions:1) I previously asked about a strange motor noise ,but now I am confused. At idle there is a pulsating noise that varies with the RPMS. At higher speeds the noise either goes away or is masked by the motor and wind noise. BCB said previously it might be the cam advance, but someone else told me it might be the air compressor. 2) When I trim the motor up or down, the defalt light comes on and says the battery voltage is low. By checking the smart gauge the voltage drops to about 10.8 volts. When I stop trimming, the notice goes off and the beep quits. Running at about 4000 RPM the voltage reads about 11.53) If you are facing the back of the motor on the left corner just below the cowl there is about a 1″ open hole. Is this supposed to have a cover.Didnt mean to be so long winded, hope someone can help.

[Bass Cat Boats]

I can email you some pics of the rear of a 2005 Pro XS you can look at to see if there is the hole you are talking about. Not sure about the noise. When I had some funny sounds coming from mine it was the Air Compressor pump. It had some screw issues. I know Mercury fixed the issue for 2007. Jamey@jameycaldwell.com

[Bass Cat Boats]

The hole in question is going to exhaust water and should be open if it is the one we assume it is. There should be a rubber boot in that hole.As for the noise you are experiencing, and voltage issue, we would have to suggest a visit to the Mercury Dealer. This one is sounding more like another item other than the noise we assumed it was in the earlier post. This is not the cam vibration.BCB

[PhilAddison]

Go to a dealer as BCB as suggested. Your voltage could be low for several reasons including a battery problem, but it could also be a loose belt or alternator problem as well. There are way too many symptoms here for anyone to be able to tell you exactly what your problem/s are and the safetest thing to do is visit a Mercury mechanic. Good luck!

[Bass Cat Boats]

You ought to at least check the cables at the battery and motor end before hitting the dealer. Corroded connections cause high resistance. That trim pump makes some pretty good pressure and draws some current to make it happen. If there is a high resistance connection anywhere, that will cause the voltage to the motor to drop significantly. As will a weak battery.I once had a trim motor that had an internal armature problem and it was a real current hog, to the point that it burned the contacts on a couple of trim relays before I figured out what was going on…So it could be something simple, or something more complicated…2008 Pantera Classic2014 Mercury Pro XS 200

[Bass Cat Boats]

While OT57 is right in the battery connections causing issue such as this, if that does not solve it, then a trip to the dealer is in order. Battery connections will not effect low voltage while running from our experience. BCB

[basscatbat]

Thanks so much everybody. Will go to dealer and check it out.

[Bass Cat Boats]

Went to dealer, Duncan Marine, blown fuse in charging circut, motor noise normal air compressor, rubber plug missing from motor to cover access hole. Great dealer great service.

[Bass Cat Boats]

While you may have been able to figure this all out, we felt it was best to visit the dealership. We are glad you did and it sounds like they got you covered! Glad they were able to help! BCB

[PhilAddison]

If you think something is wrong with your engine always take it to a dealer. Its under warranty and youre paying good money for that warranty. Glad it was a simple fix and glad it was taken care of in satisfying fashion.

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