Hi everyone
Need a chain tensioner, been looking where to buy but cannot find one?
Any leads please?

Which part in particular do you need the tensioner or the rail or the guides that the chain runs in.

motobins website .. look in k75 engine parts

the current k75 version fits all the k100 8 valve versions

good luck

Thanks Charlie, will check it out
Rick, replaced guides and chain, refurbished the tensioner and looked ok
but still rattling around as you back off from 2000rpm while in neutral

cheers

The engine ALWAYS drives the cams whether accelerating or decelerating fast or slow so if there is a rattle when you back off then it is not the cam chain. I would be looking for drive train slack.

Thanks Rick, will delve in a bit further
the rattling is coming from the cams area of the chain
Can you explain a bit further on the the drive train slack please 

Had a look at motobins under K75 parts, tensioner looks different to mine
no parts under k100

yes looks different with a machined part on the back , which fits into the crankcase neatly once assembled , part of the tensioner assembly.

the item has a different ratchet system for keeping tension on the chain guide

the k75 item fitted on fred

Arrowkeen wrote:Had a look at motobins under K75 parts, tensioner looks different to mine
no parts under k100

In Max BMW's parts fiche, the part numbers for the K100RT and the K75RT chain tensioners and tension straps are the same.

Arrowkeen, one catalogue I use frequently for its ease of use, is much like the others that are available online, is THIS. It's called realoem.com and if you use an ad blocker on your browser it's clean and fuss-free. You can enter the last seven digits of your bike's VIN and it'll pull up the model you're searching for parts for. Once you gain an understanding of the sections of BMW's ETK (electronic parts catalogue) it's a cinch. Once you're in to the section you desire, click on the part number listed and it'll show you which models the part fits and also whether there are superseded numbers. The pricing is not generally accurate where shown, however, and it knows whether your bike, or the bike you're looking up part numbers for, is a US model or has US model specs, as they put it in the actual ETK, 'The Rest of the World'. Here's another link below that'll take you straight to the catalogue. 

Another hint for you, go to the Profile tab above, click on Signature, scroll down and enter your bike's year and model, even the VIN, then save it, so when you ask a question we know what the specifics are. It appears as below in mine and in other member's posts.

https://www.realoem.com/bmw/enUS/select?product=M&archive=0

Arrowkeen wrote:Thanks Rick, will delve in a bit further
the rattling is coming from the cams area of the chain
Can you explain a bit further on the the drive train slack please 

There are 2 drive trains one is the clutch/transmission/drive shaft and the other the alternator drive section with the cushion drive or monkey nutz as many call them being the area I would look.
You say the noise is from the camshaft drive area does the noise appear on an even throttle or only when you shut the throttle as the engine slows to an idle.

Thanks Guys
Have ordered the the tensioner from motobins
have to read up on how to set the cams up again, thought I did it correctly, that is all marks lines up
fitted new chain and found chain was a bit slack between the cams
I cannot remember if I set cylinder number to TDC first though
when it arrives, will try again, will take photos this time

cheers

Thanks Rick
It idles nice, bringing the rpm up slowly up to 2000rpm, sounds great, after that, get slight rattle
as it comes down from past 2000rpm, the rattling starts, in the cams area and the alternator area
have tried it with alternator out and still the same, pulling clutch in does not make a difference
did new rear main seal, clutch plate, clutch boot etc.
Everything in the intermediate section looked in pristine condition, still kept the old springy thing though

Thanks

Yay, chain tensioner has arrived from motobins