Added Oil -- Got blue smoke???

[Sunbeemer]

I added ~ 4 oz of oil yesterday with the bike on the centerstand, which brought the oil level up to the middle of sightglass, and it started up with an astonishing puff of blue smoke from the exhaust. Does this indicate worn valve guides or seals at only 21000 miles, or is this one of those, "They all do that" things?

[DJ Downunder]

They all do that..

DJ

[ebincia]

My (R1150R 2004 always does that. In fact all my BMW motorcycles "K-Bikes" included have done the smoke at start up thing.

[towerworker]

Sunbeemer

Yeah pretty much they all do that at one time or another. But typically they do that if the bike was on the side stand. Mine would do it sporadically but only if it were on the side stand for a while. Other times it would not so it's not like it does it all the time but occasionally.

Why sometimes and not all the time? I don't know but has to do with oil seeping into the left jug's combustion chamber when the bike is leaning left on the stand.

Maybe someone like Boxermania, or CycleRob will see this and give us the straight scoop!

One thing I do know is----don't let it worry you. "They all do that"

Wayne

[ebincia]

Sunbeemer

Yeah pretty much they all do that at one time or another. But typically they do that if the bike was on the side stand. Mine would do it sporadically but only if it were on the side stand for a while. Other times it would not so it's not like it does it all the time but occasionally.

Why sometimes and not all the time? I don't know but has to do with oil seeping into the left jug's combustion chamber when the bike is leaning left on the stand.

Maybe someone like Boxermania, or CycleRob will see this and give us the straight scoop!

One thing I do know is----don't let it worry you. "They all do that"

Wayne

towerworker,

My experience has been that it is not how long the bike is on the sidestand , but rather how long it is between engine shut down and being leaned onto the sidestand.

Try this, shut the bike off while you are still astride the bike and it is still verticle. Wait 5 to 10 seconds , or so and lean it onto the sidestand and dismount. With this method (regardless of how long the bike sits on the sidestand) there will be no smoking at start up. This has been my experience on both my "K" , or "R" bikes.

Logically, there is less probability of oil entering the left cylinder if the engine is shut down seconds prior to leaning on the sidestand. However, the smoke at start up is not a problem and the amount of oil getting into the cylinder is very minimal. A little oil makes a lot of smoke.

[Sunbeemer]

Thanks guys, I feel better about it, I think.

Towerworker, I've noticed this while on the side stand too, more often while the engine was still breaking-in, but as you say, not always. I figure it might have something to do with where the piston stops in its bore - maybe oil gets past the rings when its down at the bottom of the cylinder? What surprised (and concerned) me this time was that it happened after I added oil to the top end, which suggests the oil somehow got into the cylinder through the head.

I think the occasional "Wank" noise I get when starting (mentioned in a previous post) is related to the bike leaning on the side stand and letting oil into that cylinder, since I sometimes notice a blue puff then, and it acts like its got a fouled plug when I try to start it again. Now, when I use the side stand, I lean it to the right for a second or two before starting and it hasn't happened again. Maybe doing that dumps the oil out of the left cylinder? Anyway, we'll see if that still works after it warms up, since it seems to happen more when it's hot.

[OU812]

My (R1150R 2004 always does that. In fact all my BMW motorcycles "K-Bikes" included have done the smoke at start up thing.

I have owned 3 K-bikes, and non of them ever smoked. My R's only did that when I left it on the side stand. Now that I think about it, they all did. But the K's never smoked off the center stand. OK, none my my BMW's ever smoked when they were on the center stand ( except my cars, they all did).

[CycleRob]

My bike has pumped out the huge blue smoke cloud maybe 4 times in over 58,000 miles. The day I picked it up at the dealer (it freaked out the bystanders, including me) and 3 other times with the sidestand allowing a severe lean angle on uneven ground with a very hot engine shutdown. Day one at the dealer the salesman said "It's been sitting on the sidestand about 2 weeks now, that's OK".

Here's how it happens: When you turn the key off one of the two pistons will most likely come to rest up against or just into the compression stroke. It's the one "stroke" that provides the most resistance. You may remember just how much when you turned the engine to TDC for the valve adjustment (sparkplugs IN !!). Well, when the combustion chamber is really hot and the bike is leaned way over - - - especially when the oil level is top of window - - - the oil will spill into the cylinder against the back side of the piston. Then as the hot combustion chamber, with both valves closed, cools off, a vacuum occurs. Just like the science experiment where the can with the boiling water in it collapses right after the heat is removed and the cap is screwed on. For the OilHead engine the oil on the backside of the piston gets sucked past the rings, now made even easier because there's no real sealing pressure pushing the piston ring evenly against the piston's ring land.

When the engine starts later on, oil of 1 drop or 3 to as much as 2 tablespoons will be blown out the exhaust in a few seconds. In the exhaust pipe it will continue to be vaporized in dramatic fashion for a few seconds to over 2 minutes, depending on the amount of oil internally leaked and expelled.

I haven't seen a blue cloud from my 2002 bike in years. If you want to never see the blue cloud again, use the centerstand with a hot engine shutdown -or- maneuver the bike to avoid those severe sidestand lean angles -and- keep the oil level at center-red-dot or below to lower-red-ring.

.

[allanj255]

I place a block of wood under my side stand when the bike is parked in my cramped garage to reduce the lean angle. When out and about I tend to use centre stand or leave the bike upright for a few seconds after switching off before placing on side stand.

[towerworker]

I just knew the pros would come out and enlighten us all!

I knew there had to be a logical explanation for the occasional smoking and I guess I might have figured it out myself if I had sat down and really gave it some thought. Makes perfect sense now.

Thanks guys!

Wayne

[JohnnyLunchBox]

Noticed my wife's R1150R do the blue smoke puff thing a few times. Glad to hear that they all do that. My immediate thought was bad valve guides, but the explanations given here are more than satisfactory.

Could this be part of the natural oil comsumption propensity for some oilheads?

[geothepencil]

I've always been of the ebincia school of thought about shutting down and THEN leaning it over.
geo

[Sunbeemer]

I'll definately try the ebincia method of engine shut-down and delayed dismounting. And thanks Cyclerob for another cleverly deduced and clearly explained mechanical demystification!

[ebincia]

I'll definately try the ebincia method of engine shut-down and delayed dismounting. And thanks Cyclerob for another cleverly deduced and clearly explained mechanical demystification!

Sunbeemer,

If your oil level is somewhere between the center-red-dot and lower red ring then this method will work every time.

On K-Bikes with the all the cylinders lying flat on the left side this tended to be a source of much discussion for many many years. I've had three K-Bikes K100 198?, 1996 K1100LT and a 2000 K1200LT. These 3 bikes responded favorably to this shutdown procedure (if the oil level was in the lower half of the circle), but would otherwise smoke randomly at start up.

Magazine test editors of the 1980s commented on the fact that the BMW chase vehicles crew would come behind and place the bikes on the centerstand while they were in a restaurant eating, so as to avoid the embarrassment of a smokey start up.

When I got my R1150R and my old R80GS I continued to use the vertical engine shutdown method because of habit more than anything else.

In reality a little oil burning off in the cylinder does no harm, and the "K" bike crowd of the 1990s claimed that it lubed the top end in some way! I think the German two-stroke tech gurus dreamed up this idea as a solution to BMW's quirky engineering practices

[boxermania]

Oil rings just like ridge seals, commonly in use on most automotive applications are designed to control splash but not direct contact or inmersion in oil. Under the latter they don't function well at all.

Regarding the Boxers and the blue puffs of smoke there are three things that will take place as a result:

1) There will be the "dreaded" puff of blue smoke. Actually nothing to worry about as what is happening is the burning of the oil. that seeped past the oil ring. On the other hand if the smoking is continuous, valve seals, valve to guide clearance or worn oil rings will be the culprit.

2) The majority of engine wear occurrs upon starting the engine so additional oil in the left jug will somewhat compensate for that.

3) Last, the downside of burning additional oil, now and again, either by overfilling or extreme lean angles is that carbon deposits will be more prevalent in the left cylinder. Once again if the bike is ridden "with gusto" and like our good friend Pat used to say..."in the happy zone" or above 5k rpms.

So, the bottom line is "Don't panic", if a little puff of smoke shows up after start-up.....it is just a reminder of one of the idicioncraices of the boxer engines.

[Sunbeemer]

Roger that.
But then why would oil seep past the rings after having just added some on the center stand?

[boxermania]

Sunbeemer

Only if you overfilled.....

[Sunbeemer]

Didn't. After running for a while (it got plenty warm!) and doing the side-stand/centerstand fandango, it was right smack dab in the middle of the window, right where I try to keep it!

[boxermania]

Sunbeemer

Ooops.....don't have an answer for that one.....keep a close eye on it.

[Sunbeemer]

Willco! Thanks Boxermania-san!