3L, XS or ProXS Rattling Excessively? New post with pictures

[EuropeanAM]

Previously, one of our members had posted a write-up regarding this subject. Unfortunately, the photographs and writeup were moved to a website that required viewers to sign up for a membership (and thus, the topic was removed by me).

To help those of you wishing to use the information, I'm posting some pictures of my own from an engine we did here in our shop for one of our BBC customers.

---------------------------------------------------------------------------------------------
Important:

Anytime an unusual rattle is noted in your engine- it should be immediately investigated. Aside from the obvious mechanical problems inside the engine or gearcase, loose hardware is one of the most common causes. Some commonly found "loose" items can include:

-Anodes
-Propeller
-Cowling Latches
-Steering Linkages
-Shift Arms/Brackets
-Belt, Tensioner or Compressor Pulley
-Side Mount Covers
-Engine mounting bolts or Jackplate Hardware

If all of the above have been checked, it might be worthwhile to remove the lower cowlings from the engine, and inspect the area of the driveshaft housing BELOW the powerhead, at the front (as pictured below) for rubbing/chafing:




IF you note this type of chafing/rubbing, here's a simple means of addressing the problem WITHOUT "modifying the product":

Obtain a piece of traditional 5/8" ID Fuel Line Vent Hose. Cut a 3/4"- 1" long strip, and install it over the Powerhead Retaining Stud/Nut as pictured below:

LowerCowlingFix.jpg

REPEAT the above steps for the OTHER SIDE (making sure that you've covered the affected area on both sides of the engine).

Reinstall engine cowlings, and enjoy a little quieter operation!
-------------------------------------------------------------
Another option (less effective, IMHO):


Clean the area well with a solvent to remove any grease, oil or debris.

Obtain some 3M (or any other suitable brand) double-sided trim adhesive (see picture):



Cut a piece of the stripping approximately 1" in length. WITHOUT REMOVING THE OUTER PROTECTIVE COATING (IT WILL REMAIN IN PLACE), apply the tape to the SHORT side of the affected corner (as pictured below):




Mold the material around the bend, and firmly adhere it to the remaining (longer) side. DO NOT remove the protective backing!






This topic is now included in the Commonly Asked- Commonly Used Sticky, pinned to the top of the forum. It can be found under "Mods and Such" Section.

[bigbasser54]

Great write up exactly what eliminated the "rod knock" sound I was experiencing around 3K rpms.

[transamz9]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by EuropeanAM &raquo;</td></tr><tr><td class="quote">Previously, one of our members had posted a write-up regarding this subject. Unfortunately, the photographs and writeup were moved to a website that required viewers to sign up for a membership (and thus, the topic was removed by me).


</td></tr></table>

The restriction has been removed. You can now see it as a guest.

Here it is: http://bassnboat.com/bassnboat...ro-xs


Modified by transamz9 at 4:55 PM 2/12/2011

[ChampRunner204]

Since you have the side covers off for this Mod it would be a good time to check the screen on the water line going to your compressor. I checked mine and gald I did had a lot of grass in it.

[Tom Rollins]

+1

[hard2gard]

Don, I would add one more possibility...I was plagued with this rattling noise all last year but never got to the bottom of it until this year. Turns out my gearcase was missing a couple teeth. I was convinced the rattling sound was from the upper part of the motor but my tech figured out with a stethoschope that it was actually from the lower unit. He then drained the oil and it had excessive metal shavings which led him to the actual problem. New lower unit, no more noise.

[dukhntr]

Okay, so I am a retard. Can someone please post pics from a little further back so I can tell where to put that padded tape? Kinda hard to see in those dark pics. Mine just started the mid range rattle as well.

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by transamz9 &raquo;</td></tr><tr><td class="quote">

Here it is: http://bassnboat.com/bassnboat...ro-xs </td></tr></table>

[Tamale]

Good info. For the guys that have applied this band aid, have you had to fix the issue again?

On my boat it has made a tiny hole in the lower cowling from excessive vibration/rubbing. I'm thinking I'm going to need to wedge a piece of rubber in there. I followed the procedure and added the trim adhesive, I just dont think it is going to last long.

[Bassmannnnn]

Is there a way to see if it is the lower cowling rattle without removing it?

[Tamale]

Yeah. Run down the lake somwhere between 2800 or so and 3800 RPM's and listen for a rattle. It's loud.

You can also just tap on the lower cowling in the area shown in the above pictures and see if you hear it rattle.

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Tamale &raquo;</td></tr><tr><td class="quote">Yeah. Run down the lake somwhere between 2800 or so and 3800 RPM's and listen for a rattle. It's loud.

<u>You can also just tap on the lower cowling in the area shown in the above pictures and see if you hear it rattle</u>.</td></tr></table>

+1

[fish recycler]

Guys,
I have a 2009 250 Pro XS and for the 18 months have had a weird rattle at various RPM's (usually 3500-5200).....I ran through the procedure above to solve the rattle last night. I thought I would find a need for the tape/rubber at similar wear points on the lower cowling.
WELL, I found a wear spot in the lower cowling....on the inside upper 'bowl' part on the port side.....It was where my shifter linkage arm had significantly wore into the plastic cowling. The rear nut (pointing up) on the shift linkage arm was extremely loose and the arm had sagged and rattle against the couling making a pretty large scar. Sure glad I used the procedure and found the problem. Like stated above, if you hear a rattle, remove the lower cowling (only takes a few minutes) and investigate....I should have done it 18 months ago.

[EuropeanAM]

Chad:

Just an FYI... the nut on the end of the shift arm (where the cable attaches) should be SNUGGED, then BACKED OFF 3/4 of a TURN. Very important to proper shifting.

In many cases, we find that when the relay arm has been rubbing the lower cowling, IT IS BENT (usually caused by attempting to shift the engine when it is not running- a big "no-no").

Might be worth checking into.... the longest part of the relay arm should lay "flat" on a flat surface when removed (if not, it's BENT).

[fish recycler]

Thanks Don. I snugged the nut on that end and then backed it off a bit knowing it needed to turn. I checked the arm and it did not appear to have any unusual bends in it.....just seemed extremely loose at the nut and was sagging down quite a bit. Funny thing is I never noticed any problems or slack shifting.....I was just looking to eliminate the rattle. It was a good time to wipe any dust and residue in the cowling to keep her looking pretty.
I will give it another check before putting it into service.

Thanks again.

[Tamale]

Mine is still rattling after this mod. I am know fairly confident that the rattling sound is coming from the tilt lock lever.

I use a transom saver and have no use for that thing. Can I remove it? Is there a way to tighten it?

I can see where it is worn. When I am trimmed all the way down and run in that rattling RPM range I dont get the rattling sound because that thing is tucked up in there and firmly pressed against something.

[jaystein21x]

My rattle is finally gone!!!! I had heard of this fix a while back and confirmed the rattle location by tapping on the mid cowling. I had the mid section off for the other maintenance and applied the fix. Now all I hear is the engine through that RPM range. Thanks for the post and fix pictures!!!

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Tamale &raquo;</td></tr><tr><td class="quote">Mine is still rattling after this mod. I am know fairly confident that the rattling sound is coming from the tilt lock lever.

I use a transom saver and have no use for that thing. Can I remove it? Is there a way to tighten it?

I can see where it is worn. When I am trimmed all the way down and run in that rattling RPM range I dont get the rattling sound because that thing is tucked up in there and firmly pressed against something.</td></tr></table>

I wouldn't recommend removing the tilt/lock lever, as it's REQUIRED to service the trim system, or check the trim fluid.

You could easily determine if this is the problem, by simply wrapping a thin rubber sheet around the arm, and tie-wrapping it (this would dampen a rattle in the arm- not really a "fix", but it would help you determine if the arm is the culprit).

[canadabullet]

My 2004 250 XS had slowly over time developed this annoying rattle... I pulled the bottom pans and noticed the chafing identical to what the above posts indicated which had also worn a divot inside my pan halves... I cleaned out the worn divots in the pan with brakekleen and filled them with rtv silicone adhesive and with a dremel style rotary tool I ground the high spot off the mid section that was causing the chafing. I let the silicone cure hard overnight and reinstalled the pan halves. My motor is quiet like a brand new one now...

[Gunnar]

Found the same problem (as pictured in the top pics) on my '09 225 Opti with only 55 hours - Have a small triangle worn into the inner bottom cowling on both halfs that, if not fixed will wear all the way through!! This is clearly a design flaw Mercury should fix. Will try the tape fix but am not happy at all