I have 126K on my bike. A friend asked if I had ever changed the timing chain? I asked why? He said they get loose around 100K and should be replaced. Any suggestions on how to check it to see how loose it might be, and how loose is too loose?

You will hear a loose chain, or have timing problems. The eyeball it, you must pull the timing chain cover. If the chain tensioner is all the way up and the chain still has slack, it's time to replace it. Your '91 has a single row chain - easier to replace, and less likely to wear sprocket. Here's a pretty good how-to link from the Land Down Under: http://bmwairheadsdownunder.com/airhead_tech/timing_chain_replacement.pdf

You will hear a loose chain, or have timing problems. The eyeball it, you must pull the timing chain cover. If the chain tensioner is all the way up and the chain still has slack, it's time to replace it. Your '91 has a single row chain - easier to replace, and less likely to wear sprocket. Here's a pretty good how-to link from the Land Down Under: http://bmwairheadsdownunder.com/airhead_tech/timing_chain_replacement.pdf

I guess hitting the button 3 times during a long wait results in 3 repetitions. 🙂