My F800gs STALLS LIKE ITS RUNNING OUT OF GAS! PLEASE HELP!!

[sturgeon]

Wouldn't it be easier to just move to Canada?

[DolphinJohn]

Originally Posted by sturgeon

Wouldn't it be easier to just move to Canada?

Yah, don'tcha know.

You ever had a stalling issue on your non-canistered F800???

Ever ridden in really heavy downpours??

You like gladiator movies??

[sturgeon]

Originally Posted by DolphinJohn

Yah, don'tcha know.

You ever had a stalling issue on your non-canistered F800???

Ever ridden in really heavy downpours??

You like gladiator movies??

Nope.

Yep. Last weekend so heavy I couldn't see and had to pull off for a bit.

Dunno, got any recommendations?

[DolphinJohn]

Originally Posted by sturgeon

Nope.

Yep. Last weekend so heavy I couldn't see and had to pull off for a bit.

Dunno, got any recommendations?

That was a quote from Airplane!. The pilot asking the little boy a bunch of creepy questions. Ever seen a grown man naked, Billy?

I just thought of it because I was asking questions. I'm not right.

[sturgeon]

Originally Posted by DolphinJohn

That was a quote from Airplane!. The pilot asking the little boy a bunch of creepy questions. Ever seen a grown man naked, Billy?

I just thought of it because I was asking questions. I'm not right.

I guess I'm more into the Naked Gun series...

"Nice beaver."
"Thank you, I just had it stuffed."

[bxr140]

Originally Posted by The Griz

Seriously, man.....

I know. I have a problem calling out people when they say foolish things. I'm working on it. You're not helping.

Originally Posted by The Griz

#21 is the Venting Valve. On Japanese bikes they call it a "Purge Valve". This is how I know gases move outward from the tank at this location. The main thing you need to worry about is putting a rubber vacuum cap on the "Pressure Switch" inlet bung.

FWIW, if you disconnect the hose from the gravity valve on the tank, you can...err...suck but not blow. I suspect the reason I couldn't [ahem] blow was becuase the solenoid to the intake was closed (the bike was off).

Also FWIW, I disconnected the hose from the manifold to the solenoid not too long ago and just plugged the hose to close off the vacuum. Its ridiculously easy access. It seems to have cleared up the inconsistent throttle I was having, and it also seems to have softened up the "twitchy" throttle quite a bit, especially at slow speeds in 1st and 2nd. Possibly related (but possibly just cooincidence) I started the bike without the hose plugged out of curiosity, and the running condition seemed to be very similar to the poor running/stalling I had.

I don't think there's a need to disconnect the hose from the gravity valve, and for the sake of diagnosing the problem (rather than stumbling upon a solutinon), I suggest just disconnecting one thing at a time.

[The Griz]

Originally Posted by DolphinJohn

No, didn't have time. I need daylight (no garage). I didn't want to start if I couldn't finish.
Also, we are pretty limited down here on this small island, so I'm not sure where I will get the vacuum hose and plugs. We have a Home Depot, do you think they have it?

If you do yours tonight, please take lots of pics as you go, if possible. And maybe show what you used to plug the hoses or bungs.

Home Depot might have rubber vacuum caps. Not sure. I'm sure you could find something there that could do the trick of capping the vacuum bung.

From what I understand, there is no need to plug the hose that goes all the way back to the back of the tank from the canister (#'s 8-9-10). The only thing that needs plugging is the vacuum inlet at the fuel tank breather valve (#4). This is due to the fact the the throttle bodies pull gases from the canister at this position to be burned off in the combustion chamber.

01	16137676361	activated carbon filter	BUY	1	$48.44
02	16137699225	bracket activated carbon container	BUY	1	$7.42
03	16131465035	cable strap	BUY	2	$1.24
04	13901465030	fuel tank breather valve	BUY	1	$54.22
05	13901734443	bracket ventilation valve	BUY	1	$3.75
06	16137699445	hose line	BUY	1	$14.88
07	16137716643	hose line	BUY	1	$18.11
08	16137712950	hose line	BUY	1	$16.46
09	16117716642	ventilation valve	BUY	1	$18.43
10	11747797115	hose (4,5X9MM)	BUY	1	$12.78
11	16137704562	oval head screw (M5X10)	BUY	1	$3.37
12	16137704563	oval head screw (M5X14)	BUY	1	$3.37
13	61136918644	cable strap with bracket (L=200MM)	BUY	1	$0.92
14	13907700811	bracket ventilation valve	NA	1

[DolphinJohn]

My canister is gone. I'm sure it won't be long before it is tested, as the rainy season is here.
I looked at my air filter and it really didn't look like it could have been saturated to the point of clogging. I could be wrong, but it looks pristine.

We shall soon see.

[The Griz]

Well, I had my charcoal canister off for 1 day, and I now have it back on. I can honestly say that I didn't experience any performance gain from removing it. The bike felt exactly the same regardless of whether it's on or off. The bike runs and idles exactly the same regardless of whether it's on or off. No stalling or stuttering either way. Upon very thorough hand-on inspection of the charcoal canister system, I have concluded that it would be extremely hard for it to be the cause of stalling. The system is fully sealed, so there would be absolutely without a doubt no way that rain would effect it. When I hear reports of canisters full of water, I have absolutely no idea how that could happen. The system is very simple. Here's how it works:

In 1970 legislation was passed, prohibiting venting of gas tank fumes into the atmosphere. An evaporative control system was developed to eliminate this source of pollution. The function of the fuel evaporative control system is to trap and store evaporative emissions from the gas tank and carburetor. A charcoal canister is used to trap the fuel vapors. The fuel vapors adhere to the charcoal, until the engine is started, and engine vacuum can be used to draw the vapors into the engine, so that they can be burned along with the fuel/air mixture. This system requires the use of a sealed gas tank filler cap. This cap is so important to the operation of the system, that a test of the cap is now being integrated into many state emission inspection programs. Pre-1970 cars released fuel vapors into the atmosphere through the use of a vented gas cap. Today with the use of sealed caps, redesigned gas tanks are used. The tank has to have the space for the vapors to collect so that they can then be vented to the charcoal canister. A purge valve is used to control the vapor flow into the engine. The purge valve is operated by engine vacuum. The only problem with this system is that if the purge valve goes bad, the engine vacuum draws fuel directly into the intake system. This enriches the fuel mixture and will foul the spark plugs. Most charcoal canisters have a filter that should be replaced periodically.

So even if that "purge valve" went bad, the only thing that would cause is it to run rich. But not completely die. And these charcoal canisters don't "clog" or "plug up". Even if it did "plug up", it would be exactly the same as if you remove it. Because when you remove it, you place vacuum caps at the carbs where the gases get sucked in from the canister and burned off. Effectively doing the same thing as if the canister plugged up.

After my experience, I have a strong opinion that this system without a doubt has nothing to do with stalling. There was no difference with the thing on or off. Except that with it off it was purging gas onto the ground and in turn evaporating into atmosphere. Seriously, I'm not trying to be a hippe here, I just don't see how it could cause stalling and I didn't see any performance gains. The only thing I did see was pollution. I could actually smell the gas at stop lights and while it was parked in the garage, where as with it on I didn't. I'm keeping it on. My opinion is that this stalling business is from something else. But that's just me! I thought others may find my experience with this system beneficial. Good luck!

[Motoriley]

Rode for 3 hours in the rain last week. 20 or so minutes were in the hardest downpour I've ever ridden in 20 years of motoing. 60-90 kms per hour for 20 minutes. Was too afraid to pull off the highway since I couldn't see and assumed no one else could either and would run me down. Fell in behind a car with his four ways on. Bike didn't miss a beat. Was at pretty constant throttle, 4000 rpm or so.

[DolphinJohn]

Originally Posted by Motoriley

Rode for 3 hours in the rain last week. 20 or so minutes were in the hardest downpour I've ever ridden in 20 years of motoing. 60-90 kms per hour for 20 minutes. Was too afraid to pull off the highway since I couldn't see and assumed no one else could either and would run me down. Fell in behind a car with his four ways on. Bike didn't miss a beat. Was at pretty constant throttle, 4000 rpm or so.

See that?
Montreal.
That's Canada.
Canada= no canister.
No canister=no stall.
It's science.

[bxr140]

Originally Posted by The Griz

Upon very thorough hand-on inspection of the charcoal canister system, I have concluded that it would be extremely hard for it to be the cause of stalling.

I agree that the canister itself its probably not the source, but I wouldn't rule out other parts of the system just yet. The fact that there's a BMW memo on the tank venting in the first place is a pretty good indication of that. The electronic solenoid could be a culprit, as could the vacuum system in general.

As noted, I've noticed a real improvement (NOT elimination though) of the "twitchy" throttle since disconnecting the hose from the solenoid to the throttle manifold. This improvement may be associated with the cycle of the solenoid. I THINK the way these types of systems are designed, the solenoid is only open when the engine is idle, then it cycles closed once you raise the RPMs.

I also don't have the fuel smell problem you've indicated, and there's DEFINITELY no "purging gas onto the ground".

[The Griz]

Originally Posted by bxr140

I agree that the canister itself its probably not the source, but I wouldn't rule out other parts of the system just yet. The fact that there's a BMW memo on the tank venting in the first place is a pretty good indication of that. The electronic solenoid could be a culprit, as could the vacuum system in general.

As noted, I've noticed a real improvement (NOT elimination though) of the "twitchy" throttle since disconnecting the hose from the solenoid to the throttle manifold. This improvement may be associated with the cycle of the solenoid. I THINK the way these types of systems are designed, the solenoid is only open when the engine is idle, then it cycles closed once you raise the RPMs.

Just so you know, if you've disconnected the hose that goes from the output side of the fuel tank breather valve (that houses your supposed "solenoid") to the throttle bodies, you're letting unfiltered air into the engine (via the throttle bodies). I wouldn't recommend that. Of course doing that is going to smooth out the twitchy throttle. You're letting way more air into the fuel delivery system! And unfiltered at that!

I also don't have the fuel smell problem you've indicated, and there's DEFINITELY no "purging gas onto the ground".

I don't mean "masses" of fuel purging from the tank. I mean just a little bit. Just like every other motorcycle that has a pressurized fuel system. Enough to smell and see. On every motorcycle I've owned and ridden there has been a tank purge valve with a hose that purges very small (drip) amounts of fuel liquid and gases. If it doesn't do so, then the system is not operating properly (tank not venting properly), and I would get it checked out. So the fact that mine is actually purging like it should does not indicate a "problem", it indicates proper operation. The fact that yours isn't purging out of the purge valve is a problem, and to me is indicative of your stalling problem.

Oh, and it sounds to me like you haven't actually fully removed your canister. I thought you mentioned earlier that you just unplugged some hoses and left things in place. if you left the hose that comes from the purge valve on the tank plugged into the canister, that would be why you're not smelling or seeing gases. They're going into the charcoal canister!

[DolphinJohn]

I had a chance to ride the bike today. No rain but I did notice that the bike is idling slightly lower than before. It used to idle at about 1400 when cold starting (cold engine, not air temp-- Fla=85+). If it dropped down lower than that it would idle rough and sometimes stall. This was in dry conditions.
Now it idles at about 1100 but nice and smooth. I had it out on the "highway" at 75-80mph, and also down a little gravel/mud/big puddle road.
The bike is running great and no gas smell.
I will order and install the K&N prefilter drycharger material in the air intake tubes, and hopefully I will have my stalling issue resolved. Fingers crossed.

[bxr140]

Originally Posted by The Griz

Just so you know, if you've disconnected the hose that goes from the output side of the fuel tank breather valve (that houses your supposed "solenoid")...

As noted two posts ago, I plugged the hose.

Also as noted two posts ago, I started the bike without the hose plugged out of curiosity, and it idled like crap (similar to the stalling/poor running incidents) which is exactly what you'd expect form an engine with a vacuum leak. Nobody would expect an engine with unmetered air to run anywhere near correct. I didn't ride it around the parking lot, but perhaps I will sometime this week, just to see if it mimics the conditions folks (including myself) have experienced.

And FYI, it is not a 'supposed' solenoid, it is a solenoid.

Originally Posted by The Griz

I don't mean "masses" of fuel purging from the tank. I mean just a little bit. Just like every other motorcycle that has a pressurized fuel system. Enough to smell and see.

I park my bikes in my garage, and I've never had a motorcycle smell or leave visible indication of gas dripping. Okay, except for my KLR...but that bike had issues...

Originally Posted by The Griz

The fact that yours isn't purging out of the purge valve is a problem, and to me is indicative of your stalling problem.

I think you might be a bit premature with your diagnosis, mostly because I haven't had a stalling or poor running problem for 3 months and 3000+ miles.

Originally Posted by The Griz

if you left the hose that comes from the purge valve on the tank plugged into the canister, that would be why you're not smelling or seeing gases. They're going into the charcoal canister!

I didn't fully disconnect the canister from the system. I purposely only unhooked the hose from the solenoid to the manifold so only one variable was changed--specifically, the evap system to the engine. As BMW has already acknowledged, some bikes have a problem with the evap system to the tank (the 'tank vacuum' problem), but I didn't want to make both of those changes at the same time, especially since my bike didn't indicate a vacuum problem when I took it in for the fuel gauge.