Vibration on overrun?

[ben73]

Hey guys,

I've been a lurker here for some time as I have much to learn and not much experience with the R1150R.
My bike is a March 2005 build with about 50k miles.

I wanted to ask if its normal to feel some vibes through the bike on the overrun, or while engine braking?
I wondered if the mild vibes and associated mild rattle / clatter could be a timing chain issue?

I've done all the normal tune up adjustments, valve clearances, TB sync etc.

Is this normal, or acceptable? Does an 03/2005 bike have the latest and best cam chain tensioner?
Anything else I should be looking at?

THANKS!

[fpgirard]

Is there a certain rpm that it's most noticeable? There is always going to be some vibration in the bar ends but I guess that I'm used to it and don't have any other reference point (other than the my previous K75 which was silky smooth). Mine is at about 65 at 5K rpm - it's buzzy - but smooths out at higher revs.

You should check into the cam tensioner - do a quick search to see if your manufacture date incorporates the new tensioners - mine didn't and installing them made a big difference.

p

[Sunbeemer]

Welcome ben73.
You can easily determine if your tensioner has been upgraded: if it has a 15mm bolt head it has, if not it will be 17mm.
Like fpgirard said, "buzzy" is not that unusual, but rattling could be the old style tensioner which you'd also hear at start up.

[ben73]

Thanks guys.
I'll pop a rocker cover off and look at the tensioner.

It's quiet on startup and at idle, it's just a bit noisy when engine braking..

[Sunbeemer]

No need to remove a rocker cover to measure the tensioner's bolt size, just put either a 15mm or 17mm wrench on it to determinw if it's been upgraded. It's located on the backside of the left cylinder close to the engine block behind the intake manifold tube just under the telelever pivot.

[fpgirard]

SB - i saw a note somewhere that there were some *old* style tensioners that had the 15mm heads. I was going to suggest the same as you but was it cyclerob that mentioned this? Now, i'll need to look as well.

[ben73]

OH....

I came here to post a thanks, and to say I have the updated tensioner as it has a 15mm head!
I did read the new type was introduced in Feb 2005, and my bike was built in March 2005 so it *should* have it.
Maybe I'll just remove it and look at it to be sure.

I'm not convinced my issue is related to the cam chain anyhow, or even if it is an issue. I wish I could ride another similar bike, maybe it's just a characteristic of a large 2 cylinder horizontally opposed motor and I shouldn't expect it to feel as smooth as a Jap 4 cylinder...
It runs great and is quiet and smooth at all times except when engine braking / over-run.

Maybe it's normal and I'm just too fussy

[Sunbeemer]

Actually there were two upgrades introduced by BMW for the cam chain tensioner, but the second one was not much of an improvement, thus the third. Unfortunately I don't know the bolt size of the second "upgrade", but seems it was right about the time your bike was made. Might be worthwhile to search the archives for this topic as I seem to remember a picture posted showing the difference between them.

[jm1515]

Actually there were two upgrades introduced by BMW for the cam chain tensioner, but the second one was not much of an improvement, thus the third. Unfortunately I don't know the bolt size of the second "upgrade", but seems it was right about the time your bike was made. Might be worthwhile to search the archives for this topic as I seem to remember a picture posted showing the difference between them.

2nd upgrade has 15mm heads also. This is what was installed on my '04, built in June of '04. I think the last upgrade was first installed on the GS ca2005 model....