Secondary Air System?

Ok, this is starting to make more sense. Will be really interesting to confirm this hypothesis.

All I know is that I plugged the line as the decel popping was bonkers. Once plugged, popping gone. YMMV and all that yada yada.

FWIW, Remus pipe, Akro can, PCV and as of yet unhooked AT. As smooth as can be from idle through redline with no dead spots.

Need to hook up the AT, COBDR is 3 weeks away

It would be great to know when this function is active.

Is there anyone who would be willing to connect a bulb (or 12V LED) across the two wires going to the SAS solenoid and then riding with the bulb in view so we could all get an idea when the SAS system is operational?

RB

I'd do it. Where is that critter located...???

A couple of images for reference.

I think the valve that controls air to the SAS is #17 in this image.

Part #19 from the above images is #4 in this image.


The connector from BMS-K should attach to #17.

We are all shure this is NOT a regular crank case vent system..... Someone knows that as it passes through the o-ring #3.... it in fact goes deep into the exhaust part of the cylinder, not just into the crank case......

Well, it is definitely not regular but I understand #3 is the crankcase breather and is separate from the SAS. Discussed a bit here in the thread.

Hose #2 in the above diagram connects to the airbox.

I see.... #2 hose is for the crank case breather system, and #4 is for the SAS system. Funny thing though, I do not remember any internal parts protruding into the engine through the valve cover, as where the #4 hose connects to it..... Anyone have had the valve cover off recently that can verify this.......??????
I would buy that #2 is the SAS hose, and #4 is the crank case breather system......IE reversed....

I thought that at first (back in 2010... I've been bird-dogging this topic for sometime) but as I looked at the manual and fiche, started to doubt it.

Re-read JoelWisman's description of how the SAS works.

He is referring to #17 in this drawing.

He is referring to #5 (the valves) and #4 (how the valves are bolted to the cover).

Why BMW makes this so obtuse is beyond me! This topic is not covered in it's entirety in any single piece of published documentation that I have found.

Erling, do you get decel popping? With the wide band 02 sensor any air injected will cause a bad reading, but you knew that already.

I get the SAS system.... But are having a hard time buying the diagram as SAS. ( i might be an idiot at that though...) But as I had the valve cover off ( #6) I do not recall anything right under there that were in contact with the exhaust gasses. Think about it..... This thing (SAS) supposedly injects air into the exhaust slip stream....right..... There should be nothing right under the valve cover that has any contact with the exhaust system, as pictured above. That to me puts a positive ventilation into the crank case, known as a PCV. So to clarify..... I am certain Joel knows his stuff.....But I am not agreeing with all he says in the post referenced. I simply cannot see that right under the valve cover is exhaust pressure as the diagram above indicates. Pardon my ignorance, but to me, it does not add up. Holding back exhaust pressure right at the head is a big thing. Dang..... I wish I had looked at it more , when I had it off......:huh

I am still not sure the 8GS has air injected into the exhaust stream. I am very specific in saying this as such. Inject air into the exhaust stream.... That doesn't mean I am right..... Have been wrong many times before.... No popping on decell, anymore. It stopped with the pc-5/AT install. Like a switch.

Read this article from 2008. It seems a pretty open and shut case.

http://www.webbikeworld.com/BMW-motorcycles/bmw-f-800-gs/

Nominally, the engine provides 85 HP at 7,500 RPM and at 5,750 RPM it sends 61 pounds-feet of torque to the sliding bearing based crankshaft.

Thanks to the regulated three-way catalytic converter and secondary air system, the twin also releases its power in a way that is environmentally friendly.

And the engine is balanced by BMW's system that is unique in standard motorcycle design: an additional swivel con-rod balances the first and second level mass forces and ensures that the two-cylinder functions with the minimum of vibrations.​

Ok so more specific..... I am not convinced the diagram above puts air into the exhaust, sorry, I just cant see that. Into the crank case yes. Right under the valve cover are the valves, I fail to see the path from there into the exhaust system, thats all.....

I agree, this is very confusing and the paths through the cover via the reed valves into the exhaust is a mystery. I cannot find a drawing that clearly shows this.

Seeking someone that has had one of these motors disassembled to chime in.

Someone would need a head in their hands to probe the route of the SAS ducts- or at least look inside the exhaust ports with the headers off. The ducts however definitely communicate with the valve cover through the central spark-plug gasket, between the plugs.
Look at the first pic in the valve clearance thread, the two holes are obvious.

These pics from Oso Blanco's valve adjustment procedure?

Yes, I think those are the channels (ducts) we are talking about. Couple other pictures that would be helpful; first, the underside of valve cover gasket to see how the channels match up to the reed valves. Second, the underside of a disassembled head to see where the channels exit into the exhaust port.

Good of you yo post those pictures. We are getting somewhere now..... It looks like the two holes in the middle matches up with the two reed valves, as you explained. So if we assume that those two channels goes to each bank's exhaust chamber, them we have a deal.

Given that BMW touts Secondary Air as a pollution feature, I've seen enough to be convinced that that is what they are. ...

I think you should pull the connector to your solenoid at least although it may cause an error code. Otherwise this air will fool Autotune.

Agreed...... So, if I pull the plug on the system, by plugging the hose going from the valve in the airbox, to the reed valves on the valve cover, how do you suppose the BMS-K, can know of this...... Disconnect the valve, yes....but just plugging the line, simulating a stoppage, not so much. From another angle, I thought you mentioned somewhere earlier, that the SAS system would be compatible with the PC-5....or did I not read that correct, and it was not compatible with the PC-5, and compatible with the LC-1....????