I have a new 09 250 pro xs and when I'm running about 3500 rpm or higher i hear a noise that sounds like two metal washers vibrating together. Cant tell if it's under the cawl or outside. I've check every bolt and nut and can't find anything loose. Anyone have any ideas.
It is probably reed slap from the carbon fiber reeds..
There is a harmonic resonance vibration at approximately that RPM. Much of the sound you "perceive" does come from the carbon fiber reeds.
It can be amplified by anything loose on the engine..... anodes, cowl latches, engine mounting bolts not properly torqued, etc.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I have the same problem 07 250 pro xs. Dealer said engine harmonics, but I doubt it as do 3 pros who rode with me and agreed something is loose. It doesn't seem to affect the engine or performance in any way, just annoying and pretty loud.
If you hold some of the hydraulic steering arms or connections, it seems to dim somewhat, but it is hard to pinpoint.
Please post if you figure it out.
2019 Ranger Z520C
Mercury 250 Proxs 4 stroke
I had the same noise on my 2004 250XS. It's pretty common on the XS motors. But mine went away when I shimmed my steering to take the play out of it. So I suspect mine was left/right oscillation.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by John Jackson »</TD></TR><TR><TD CLASS="quote">I had the same noise on my 2004 250XS. It's pretty common on the XS motors. But mine went away when I shimmed my steering to take the play out of it. So I suspect mine was left/right oscillation.</TD></TR></TABLE>
Very good point, John!
One more thing I'll add:
Many of you folks are running these engines on "aluminum jackplates". Commonly, I find that the engine was mounted directly to the jackplate, without any adhesive or sealant.
Adding a 5/16" bead of "3M 5200 Sealant/Adhesive" to the transom brackets (before mounting the engine), seems to make a "marked difference". This is essentially "duplicating" the thin buffer of material that would normally be present when the engine is "directly transom mounted".
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Thanks John and I will give your suggestion a try.
Mine is mounted directly to the transom. Could there be a seal or a problem there?
2019 Ranger Z520C
Mercury 250 Proxs 4 stroke
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by twofin »</TD></TR><TR><TD CLASS="quote">
Mine is mounted directly to the transom. Could there be a seal or a problem there?</TD></TR></TABLE>
Unlikely... the engine (and bolts) should have been "sealed" to the transom when the engine was installed.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
this is a must! DON told me about it and sure enough it helped, still the reed slap but not as it was also I found the side plates (lower engine mount covers) can vibrate as well--- take off and add a little silicone to the clips inside and a drop to the screw (philips head) it stopped even more noise. the jackplate deal works.
JEFF MURRAY USMC
RANGER Z521C & 15 VERADO PRO 250
DEEP CREEK LURES and ROSE JIGS
GREENFISH TACKLE and ALX RODS
Mine does it between 3-4000, thats the motor saying "give me more gas"
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Shotgun »</TD></TR><TR><TD CLASS="quote">Mine does it between 3-4000, thats the motor saying "give me more gas"
Exactly. It's nothing a little bump on the throttle can't cure.
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