K11 Owners Group

Moondog · Posted: Tue Apr 08, 2008 6:23 am Post subject: Timing chain

Started my 96 K1100rs and its got a rough sound coming from the front of the engine. I suspect the timing chain is rattling around.

Is there anyway to check how tight the chain is suppose to be?

Should I be able to push the tension adjuster piston up and down?
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Scott_Anderson · Posted: Tue Apr 08, 2008 8:03 am Post subject:

I havn't been into the front of mine but I seem to remember from some other forum posts that the piston is presurised by engine oil pressure when running. Something else that was mentioned was that the 'tension rail' that the chain rides on can wear thin, thus not allowing the piston to maintain proper tenson.

I'll look and see if I can find you a link.

Edit: Your other forum post is where I would have sent you. TheMason should know the answer.

Ride Safe.

Scott

k1100rsr · Posted: Tue Apr 08, 2008 11:50 am Post subject:

Look at the link Shoganai posted in another tread : http://www.bmwons.ca/k100/k100.htm ,there are some vise words about timing chain.

But if you got rattling sound in front of the engine,there are not many other things than a new chain,rails and tensioner that helps.

You must also change the tensioner bow,not just the plastic rail. This because an worn bow can let to much oil leak out of the tensioner,and give the chain to little presure.

If you drive any longer,you will kill your spockets too,and at last,the whole engine.
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Al. · Posted: Tue Apr 08, 2008 5:03 pm Post subject: Chain

Don't know about this but the K75 tensioner is spring loaded which takes up the slack as the chain loosens. The tensioner is ratcheted so it can't go back down and slacken the chain again. Idea

Flying Duck · Posted: Tue Apr 08, 2008 5:06 pm Post subject:

Similar setup for K11s. This is why you have to hold the chain tensioner down when you remove the cams to swap valve buckets.
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kstones · Posted: Fri Apr 11, 2008 4:04 pm Post subject: Timing chain

The tensioner is oil pressurised/forced; but there is a central support in it which is spring loaded and turns in a helical spiral in the tensioner piston and when it turns, if the tensioner is able to go up a "notch", it goes over a sort of ratchet in the base which prevents it turning back and letting the chain sag when the engine stops, so the timing chain remains at or very near the tension it was at when the engine was running. all that said, after i took mine to bits - i couldn't get out the top slide rail, but it doesn't do much anyway; but the lower rail which has the oil forced piston under it does the real tensioning didn't have a mark on it after 56000 miles. and since i put it back together,no changed parts, it has been a bit quieter in my perception.
your chain should not be the cause of rattle; it's not really got anything to rattle with!; you should not be able to push the tensioner up and down - how did you get to it anyway!! i am more inclined to think its the alternator drive, or the va;ve gear till it gets plenty oil or the i hope normal clanking from the clutch / gearbox end which i have too - i was going to have a look in but getting the ABS 2 and those steel pipes put me off. it goes fine anyway - 120 miles around Yorkshire hills on Wednesday, great.
hope it helps
Tony.