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-   -   What's that Ka-Ka-Ka-Ka Noise on Deceleration? (http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/565590-whats-ka-ka-ka-ka-noise-deceleration.html)

Dana in Philly 09-21-2010 07:26 AM

What's that Ka-Ka-Ka-Ka Noise on Deceleration?
 
Hoping you geniuses and semi-geniuses can help me diagnose this one.

Bike: 2000 R1100S (Mandarin, if it matters), with just under 24,000 miles.

Noise happens when decelerating so a stop (e.g., coming to a stop at a stoplight). Sounds like a "ka ka ka ka ka ka ka ka ka" sound, decreasing in frequency as the engine decelerates. I can make the sound more prominent by pulling the clutch in and coasting to a stop, but even with the driveshaft engaged (i.e., clutch not pulled in), the sound occurs. Sound is not present when the bike is revving or running steady at rpm. It's only a deceleration sound.

My guess is that what's happening is the flywheel is shedding excess momentum into one or more of the cam chain/s, and my cam chain tensioner (or one of 'em) needs adjustment. Plausible theory? Anyone else experience something similar?

TIA,

Dana in Philly

Bob Hancock 09-21-2010 07:43 AM

It might be just calling you names. Or some ka ka like that.
Other than that, it's anyones guess without hearing it. :)

Guest24 09-21-2010 07:59 AM

Timing chain tensioner begging for attention.

SergioK 09-21-2010 08:22 AM

Quote:

Originally Posted by Nail24 (Post 5573178)
Timing chain tensioner begging for attention.

It would make that noise at idle as well.

Guest24 09-21-2010 08:26 AM

Quote:

Originally Posted by SergioK (Post 5573229)
It would make that noise at idle as well.

It was either that or playing cards in the spokes; but, it's not a GS.:D

cageyar 09-21-2010 08:38 AM

Does the pace of the noise slow down with the speed of the bike?
If it does when the clutch is pulled in, it's rotational in the wheels/bearings/brakes, etc.

Dana in Philly 09-21-2010 08:43 AM

Quote:

Originally Posted by SergioK (Post 5573229)
It would make that noise at idle as well.

If I decelerate to a stop, and am idling, it's often there, and a little throttle blip will make it go away.

I'm still liking timing/cam chain tensioner. Bike's the right age to need the adjustment, methinks.

I only noticed this because I'd been wearing an open faced helmet this week on some lazy rides to work.

Bob Hancock 09-21-2010 08:44 AM

Quote:

Originally Posted by cageyar (Post 5573267)
Does the pace of the noise slow down with the speed of the bike?
If it does when the clutch is pulled in, it's rotational in the wheels/bearings/brakes, etc.

Or driveshaft? IOW, anything back of the clutch.

Bob Hancock 09-21-2010 08:47 AM

Quote:

Originally Posted by Dana in Philly (Post 5573275)
I'm still liking timing/cam chain tensioner. Bike's the right age to need the adjustment, methinks.
.

Well then adjust the cam chain tensioner and see what happens. It's not difficult as I recall....been awhile.

PS edit. I don't have ready access to the shop manual but isn't the chain adjusted by oil pressure? I used to hear it sometimes on start up and then it'd go away after a few seconds. So I'd check that.

Guest24 09-21-2010 08:47 AM

Timing chain slapping.:)

Dana in Philly 09-21-2010 08:48 AM

Quote:

Originally Posted by cageyar (Post 5573267)
Does the pace of the noise slow down with the speed of the bike?
If it does when the clutch is pulled in, it's rotational in the wheels/bearings/brakes, etc.

But the noise is still there *after* I've come to a stop, as the engine slows down to idle. So I don't think it's in the wheels/brakes etc.

Dana in Philly 09-21-2010 08:50 AM

Thanks all for the help. Great resource.

Guest24 09-21-2010 08:55 AM

You don't normally hear it with a full face helmet. I heard mine with a flip-up.

jduke 09-21-2010 10:28 AM

Unless the cam chain tensioner is broken, they usually quit making a racket once the oil pressure builds up.
Happens with or without the clutch pulled in, sound decreases as speed decreases...
My money is on the driveshaft.

Dana in Philly 09-21-2010 11:20 AM

Quote:

Originally Posted by jduke (Post 5573464)
Unless the cam chain tensioner is broken, they usually quit making a racket once the oil pressure builds up.
Happens with or without the clutch pulled in, sound decreases as speed decreases...
My money is on the driveshaft.

Acchhh, now there's a lovely thought. Hope not. I guess I'll:

1. Top up the oil to mid-sightglass (although in my experience that's always too much for a beemer). See if the noise goes away.

2. If not, check the tensioner, adjust if needed. See if the noise goes away.

3. If not, investigate further....

jduke 09-21-2010 11:23 AM

Checked your alternator belt lately?

Meeni 09-21-2010 11:26 AM

Usually comes from low oil pressure, the cam chains slack when the tensioners don't get enough pressure to hold the charge. More oil should make it disappear.

jduke 09-21-2010 11:46 AM

I don't think they can be adjusted and I don't think you can just add oil to make the sound disappear. The old style are a three part, tube, spring, bolt. Typically the right tensioner is the one that gives problems. It's the one on top of the cylinder and will leak down. That's what causes the "clanging" sound, until the oil pressure builds back. I replaced both of mine with the newer version and I don't hear that "clanging" sound anymore.

Bob Hancock 09-21-2010 11:47 AM

If you keep the oil level within the circle it should be fine. I doubt that a tiny bit low oil will make any difference in the symptoms you describe. The low oil and loose chain thing is a start-up phenomenon....goes away within 20 seconds.

PFFOG 09-21-2010 12:01 PM

Is Bill the cat hiding in your fairing?

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