Why do I sometimes get a puff of smoke at startup?

[PA Rider]

It seems like every fifth or sixth I start my beakster I get fairly good sized puff of smoke out the pipe. It may be happening more frequently lately. What could be causing this and is it anything to worry about?

Thanks for any help with this.

[Oilhead]

Do you keep the bike on the centerstand or the sidestand? If you keep the bike on the side stand, the oil will seep into the left cylinder head and will burn at startup. It only does that once in a while for me. Of course no smoke ever on startup if kept on the centerstand. Just another of those idiosyncracies of our engine.

[mnnden]

I'm no mechanic, but sometimes when I leave it set on the side stand for any length of time it will "Puff" out a cloud, not all the time but most times, Den

[Oilhead]

I'm no mechanic, but sometimes when I leave it set on the side stand for any length of time it will "Puff" out a cloud, not all the time but most times, Den

Yes that's right. It is the left cylinder head that the oil is seeping into and getting burnt at startup. The early K100 Brickheads were notorious for that. It would actually smoke for a few blocks. That is why everyone that had an early K100 always parked on the centerstand. They fixed it on the later K100 and K75....as a matter of fact, my '95 K75A/3 never had that problem. It actually took a few years for BMW to even address it and I remember one of the mags severely criticized them and even took a shot by saying "if this was Honda, the problem would have been taken care of in the sophomore model year.....actually if this was Honda, they would have designed the brick with the cylinder head on the right side instead of the left".

[boxermania]

+1 to the above responses, however, it is much more prevalent if the oil level is kept above the middle of the sight glass.

[towerworker]

I read this somewhere on this board some years ago. Recommended shutting down engine prior to leaning it over on the side stand. For me maybe two to three seconds will elapse before it's on the side stand. Mine seldom if ever smokes now.

Wayne

[Beemeridian]

11

[PA Rider]

Have you drained the airbox lately? If it gets filled with enough oil it will do exactly what you are describing.

I just had my beakster in for its 24k service. Would they normally drain the airbox as part of this service? They did install a new air filter. And okay...I don't even know what an airbox is.

Those that provided their input above...thanks for the center stand tip. I'll use the center stand more often now.

PA Rider

[Buckster]

Your airbox is under the tank where the air filter is at. If they changed your filter at your last service, I'm sure they would have cleaned before installing a new filter. I have not had oil collect in my airbox except for maybe a little residue.

[Beemeridian]

11

[Boxer]

Allow it to drain for an hour or so.

An hour or so?

I would go to sleep laying there that long.

[Beemeridian]

11

[Rog(UK) - Yorkshire Dales]

You two remind me of Jack Lemon and Walter Mathau in 'The Odd Couple' or was it 'Grumpy Old Men'? - in a nice way, of course!

Rog

[Beemeridian]

11