Stuck in Addis, need help - broken timing chain adjuster?
 

Hi,

Just got stuck in Addis since there is a rattling sound coming from the engine. A (kind of) mechanic took a look/hear and thought it might be the tension chain or adjuster.

Anyone who can help me think of options? I'm nog a mechanic and there is no BMW expertise here. Do I just drive to Nairobi with it since there is Chris in Jungle Junction?

The sound is rattling when ideling. It goes away a bit when at 3000rpm.

Anyone got a clue what to do?

Cheers and thanks


Niek

I've just posted a link to your thread on the F650 forum and the UKGSers forum..............hopefully someone there will be able to offer some advice.

Someone has got back on the f650 forum (thanks Komatias) sounds like your mechanic guy was right .....
"its nothing major, only the cam chain tensioner. easy to replace but will cause alot of aluminium swarf if left untreated".

I'm waiting to hear back whether he thinks it will get from Addis to Nairobi

If I remember correctly the old type cam chain tensioner only relies on oil pressure.

It's an easy fix to remove and polish the piston.
Then find a small spring which fits inside the piston and cut it to around the right length. This will sort it.
Good luck.

You don't say what model of BMW you're on. If it's an old airhead, there's nothing to worry about. Get a new cam chain tensioner (possibly a new chain too) sent to Nairobbery where a proficient mechanic can sort it easily.

On the airheads the chain is so short that it shouldn't come off the sprockets. It will rattle like hell, but there's more chance of being heard by the locals.

Here's mine mid-chain-change in Chile in 2001:


http://www.thebrightstuff.com/picsFo...ming_chain.jpg

Also, just remembered, you'll need a special tool to get the alternator rotor off.

Good luck,
Chris

Checked your personal file and found this statement/info:
Bike Model:BMW F650 GS Dakar

Is that the bike that is causing you the worry ?

Drive Safely,
Albert

Yes it is. But we found it. It indeed was the cam shaft chain tensioner. I orderded the part from Holland and I guess it will be here in a day or 5.

Thanks all for your time and advice!

Good to hear that the problem with your engine is about to be solved :)

Funny though... same problem with a BMW engine as was the cases with the Japanese bikes in the 70:ties and 80:ties (even newer?)... (cam-chain-rattling)

The cause for a rattling/slapping cam-chain on the Japanese bikes where two folds according to my mechanics:
- lengthening of the cam-chain
- wearing of the tensioner
Usually one needed to change the cam-chain when the tensioner could no longer stretch/tension the cam-chain...

If the F650 is anything like to older Japanese engines, like Yamaha XT-600, TT-600, Honda CB750, Kawasaki Z400-1100, Suzuki GS500-1100 etc checking the cam-chain for wear might be a very good idea.

I browsed over this thread completely. Should have mentioned the model in the heading. What year is it?