2018 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.

 K Bike Smoky Starts

"They all do that."

Cause:

Because the K bike engine lies flat with the cylinder head to the left, oil can seep past the piston rings into the combustion chamber when the bike isn't running. This is especially true if the bike has been left on the side stand with the cylinders angled downward.  This can create a lot of smoke when starting and is nothing to worry about. Just ride the bike to burn off the extra oil and the smoke will go away.

 

In order to somewhat mitigate this problem, BMW upgraded the piston rings in June of 1988 so K bikes with a model year of 1988 or earlier will tend to smoke more on starting.

 

However, any year K bike, if left on the side stand long enough, will have some oil seep into the combustion chamber and be smoky when started.

 

If you're bringing a K bike back to life after sitting for several years it can generate quite a bit of smoke.  This can take several minutes to burn off but is nothing to worry about.

 

Remedies:

There's really nothing you can do to prevent this from happening but there are a couple of things you can do to lessen the amount of oil that seeps past the rings:

 

1) Use the center stand.  Since the engine remains flat, not leaning to the left, less oil will seep past the rings.

 

2) Tilt the bike to the right after turning it off. Turn the bike off and tilt it to the right for 10 seconds or so before putting it on the side stand. This allows much of the warm oil behind the cylinders to drain back into the oil sump, leaving less to seep past the rings.

 

2018 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.