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2004 R1150RS Big sucking sound lifting gas cap
- Thread starter MOONDOG59
- Start date
pglaves
#13338
I believe the only vent is via the metal stub on the pump plate with the hose that goes to the charcoal canister. Something is plugged/clogged.
beemerphile
New member
Someone was asking why anyone would remove the canister. Here 'tis.
trailrunner
New member
Similar issue on 1150RS. There was water in charcoal canister.
Bingo.
Here is a brief thread- https://forums.bmwmoa.org/showthread.php?86946-2004-R1150RT-canisterectomy
I have never done it- on a bike
. Many have and I’m sure they will chime in.
Your bike should run like new again.
OM
Here is a brief thread- https://forums.bmwmoa.org/showthread.php?86946-2004-R1150RT-canisterectomy
I have never done it- on a bike
. Many have and I’m sure they will chime in. Your bike should run like new again.
OM
"This is the water drain. It allows water that gets around the cap to drain out, rather than going in the tank when you open the cap.
The other line is the tank vent. It routes directly to the carbon canister. There are two other lines attached to the carbon canister. One is the atmospheric vent which terminates near the right foot peg, next to the water drain. This allows the tank to breathe through the carbon canister. As it does so, fuel vapor is trapped in the charcoal, reducing evaporative hydrocarbon emissions. The third hose from the carbon canister is the purge line. It goes to the soenoid on the left side of the frame. The hose then goes from the solenoid and splits in two with one hose going to the fitting on the bottom of each throttle body. With the engine running, when the solenoid opens, air is pulled through the atmospheric vent line, through the charcoal in the carbon canister and into the combustion chambers. This pulls the fuel vapor out of the charcoal and burns it rather than releasing unburned hydrocarbons into the atmosphere. The purge needs to be done to prevent the charcoal from becoming saturated.
Trace the two small hoses from the tank and see which one goes to the carbon canister. disconnect that one from the carbon canister to see if it solves the problem. Put a cap over the nipple on the carbon canister and disconnect the electrical plug from the solenoid on the left side to prevent any unfiltered air from being sucked in. If you have a mighty vac, use it to suck on the vent hose you disconnected from the carbon canister. If there is an obstruction in this hose, you don't want to blow it back into the tank. If you find wet fuel in this hose, you may have a split in the line inside the fuel tank. When this happens, it can wet the charcoal, causing the vacuum in the tank.
Be careful using compressed air to blow through either the vent line or the drain line. They are small relative to an air compressor hose and if you try to flow too much air through them, they can rupture inside the tank where they have been deteriorating slowly from sitting in fuel. If there is a clog in a line, it can rupture even more easily or it may blow the debris out somewhere you don't want it if you manage to clear the clog. Applying a vacuum to the exit end of the vent or water drain hose is a safer bet"
Posted back in 2012. I lost thread and not sure who posted it. Thanks to whoever. Good info.
The other line is the tank vent. It routes directly to the carbon canister. There are two other lines attached to the carbon canister. One is the atmospheric vent which terminates near the right foot peg, next to the water drain. This allows the tank to breathe through the carbon canister. As it does so, fuel vapor is trapped in the charcoal, reducing evaporative hydrocarbon emissions. The third hose from the carbon canister is the purge line. It goes to the soenoid on the left side of the frame. The hose then goes from the solenoid and splits in two with one hose going to the fitting on the bottom of each throttle body. With the engine running, when the solenoid opens, air is pulled through the atmospheric vent line, through the charcoal in the carbon canister and into the combustion chambers. This pulls the fuel vapor out of the charcoal and burns it rather than releasing unburned hydrocarbons into the atmosphere. The purge needs to be done to prevent the charcoal from becoming saturated.
Trace the two small hoses from the tank and see which one goes to the carbon canister. disconnect that one from the carbon canister to see if it solves the problem. Put a cap over the nipple on the carbon canister and disconnect the electrical plug from the solenoid on the left side to prevent any unfiltered air from being sucked in. If you have a mighty vac, use it to suck on the vent hose you disconnected from the carbon canister. If there is an obstruction in this hose, you don't want to blow it back into the tank. If you find wet fuel in this hose, you may have a split in the line inside the fuel tank. When this happens, it can wet the charcoal, causing the vacuum in the tank.
Be careful using compressed air to blow through either the vent line or the drain line. They are small relative to an air compressor hose and if you try to flow too much air through them, they can rupture inside the tank where they have been deteriorating slowly from sitting in fuel. If there is a clog in a line, it can rupture even more easily or it may blow the debris out somewhere you don't want it if you manage to clear the clog. Applying a vacuum to the exit end of the vent or water drain hose is a safer bet"
Posted back in 2012. I lost thread and not sure who posted it. Thanks to whoever. Good info.
A lot of help here on the MOA forum.
https://forums.bmwmoa.org/showthread.php?64026-98-R1100RT-tank-vent-plugged
Gary
https://forums.bmwmoa.org/showthread.php?64026-98-R1100RT-tank-vent-plugged
Gary
Got the check valve out and that was plugged also. I couldn't blow thru the valve in either direction. Arrow was in proper orientation.
That being discovered, what do I do to the connector for the valve? Does it send a signal anywhere, now that it won't be sent, that will change the way the bike runs?
pglaves
#13338
Here are the basics: There are two lines from the tank. The drain for the cap area and the vent. Route hoses from both down to the right foot peg area as the drain line is now. There is a small hose attached to the bottom of each throttle body coming from a valve under the left rear of the seat. Disconnect these lines and install caps on the stubs at the throttle bodies. You have now vented the tank and sealed the throttle bodies against vacuum leaks.
At your leisure you can remove the canister, the extra hoses, and the valve.
m_stock10506
Well-known member
I offer you one minor alternative. I left the two hoses attached to the throttle bodies. They meet at a T connection just before the purge valve on the left side of the bike. I cut the hose right after the T and plugged the end of the hose there. This left the two throttle bodies joined together by the hose. Those hoses seem very robust and are still very soft and pliable, where I hear that the caps for the throttle bodies get hard, cracked or fall off. I just pull the hose off the TB when I do the sync and slide them back on when done. Just my two cents.
pglaves
#13338
That works. My experience is that parts store caps last about a year. The BMW caps used on K75, K100, and K1100 throttle bodies last a lifetime, or at least 24 years and still counting.
Last edited:
Everything removed BUT WAIT, THERE'S MORE!
Looking at the schematic, one side of the valve connector (two wires) goes to the Motronics but doesn't show what the signal is doing. A ground probably for the valve. I doubt the Motronics is using it for anything because it looks like the valve hasn't been operating properly for sometime and the bike has been running fine.
So for the sake of preventing corrosion on the connector, I capped the valve nipples and reinstalled the valve. I then attached the connector. Just keeping the connector protected. May be over-kill
Looking at the schematic, one side of the valve connector (two wires) goes to the Motronics but doesn't show what the signal is doing. A ground probably for the valve. I doubt the Motronics is using it for anything because it looks like the valve hasn't been operating properly for sometime and the bike has been running fine.
So for the sake of preventing corrosion on the connector, I capped the valve nipples and reinstalled the valve. I then attached the connector. Just keeping the connector protected. May be over-kill
