Rattle on start up

[Knobby10]

My '16 RTW rattles for just a second or two on cold startup. The oil appears to be clean and the level is on top of the circle in the glass. Sounds like the old cars with hydraulic lifters filling with oil on startup. Is this common for the wet-head?

 

Knobby

[narcosis]

Mine does it...always has.

[gordiet]

Mine as well...

GT

[hopz]

"oil level at top of circle"... may not be related to what ever you are hearing but it is not at the recommended level.

 

I the pre Wet-Head days that is where many of us kept the oil level. The Wet-Head engines are happiest and at the "proper" level at mid-glass.

 

If you get no other answers try that... and read the manual on the subject.

[Mike]

"oil level at top of circle"... The Wet-Head engines are happiest and at the "proper" level at mid-glass.

 

Thanks for pointing that out. BMW Motorcycle Magazine did a test on a wethead a while back and found that overfill (to the top of the glass) also led to a measurable decrease in power output.

 

As to the rattle, I get a little, probably a fraction of a second.

[Knobby10]

Came from the dealer at that level after first oil change. I'm about to change it myself and will insure a lower level as suggested.

 

Thanks guys

[JWMcDonald]

Decompression device is probably the source of the "ticking" noise at startup - see http://advrider.com/index.php?threa...-idle-in-right-cylinder-only-thoughts.938959/ for thread on advrider

[DMilan]

I think that referring to it as ticking is a kind characterization...

More like a sharp, slapping, clatter.

 

Now the throttle bodies... those might tick.

 

OP

 

It's the decompression device on a camshaft which allows the starter to crank over an otherwise high compression engine more easily.

 

Both of my departed LC did it.

 

I don't think it's a very pleasant way to begin a ride.

But that's the way it is so get used to it, it's a feature.

 

This video shows how a d-c valve works. The BMW LC version is different, but the principal still applies.

If you listen at the very end, where the fella says "that's it" you will hear a slight ting as the spring loaded weight recoils. The LC version is different, larger, and much louder.

It goes away once the bike is running smoothly at higher (than start-up) RPM.

Usually...

I've heard of a small number of bikes have an idle that is a bit too low and some clacking may reappear.

 

 

[DMilan]

Tried to add this to my above post...

editing not available..

 

The decompression valve on the LC 1200 is clearly visible on this video animation at the ~50 second mark, and again at the ~2 minute mark.

You can pause it there..

The culprit is on the end of the lower (the exhaust) camshaft.

 

I saw the You Tube video first over at ADVRider. Pretty interesting if you haven't seen it.

 

 

 

Edited September 18, 2016 by DMilan

[hefy_jefy]

Yes its the decompression lifters, if you are clumsy enough to stall the engine it makes the same noise just before it quits, as the camshaft speed drops. That first video is excellent!

Geoff

[alexp]

Normal...

 

[fastlarry]

I wonder if this is the source of a ticking noise off the left side I hear with a hot engine at idle. My valve clearances are right in the middle of their tolerance, so I don't think its them. Sound disappears at above-idle.

 

Larry

[ryan_ca1]

+1 for normal. Mine does it too, and my previous 1200's have as well.