CYYJ
Michael
The ST 1100 has a fuel valve that is operated by vacuum from the engine. This valve has been known to fail, and like most failures, it won't happen in your driveway - odds are that it will happen when you are a long way from home.
The valve usually doesn't fail abruptly and bring you to a halt. Instead, you'll experience a loss of power, as if not enough fuel is getting to the engine (which is exactly the cause of the problem). The bike will decelerate, and after a little while, you will be able to accelerate again, only to have the bike once again lose power... the cycle repeats about once every 3 to 5 minutes.
The purpose of this article is to explain how to do an "emergency bypass" of the fuel valve in case you encounter this problem when you are away from home. It's a simple fix that only requires a Phillips screwdriver, a hex-key, and a pair of pliers.
The fuel valve on my ST 1100 failed way back in 2005. At that time, I did a write-up with pictures on Steiner's My-Mc forum, but that forum has since shut down. So, here's a repeat of the post I made just after carrying out my emergency roadside repair.
1) Remove the seat, the right side cover, and the false fuel tank cover.
You might have to remove the left side cover to get the false fuel tank cover off - but, maybe not.
To remove these covers, you need the Phillips screwdriver and the hex key.
The fuel valve is on the right side of the motorcycle (see the red arrow).
2) This is what the valve looks like once you get the covers off.
Fuel enters from the hose in the bottom left of the picture, goes through the filter, makes a 180° turn, goes through the fuel valve, then exits forward into the carburetors.
3) The 'emergency bypass' is really simple to carry out: follow the 3 steps in the picture below.
First, disconnect the hose that delivers fuel to the carburetors. That hose is partially hidden in the photo below.
Next, disconnect the hose from the forward end of the fuel filter.
Finally, connect the fuel delivery to the carburetor hose to the forward end of the fuel filter.
4) When you have finished, it should look like this:
The lower end of the 180° turn hose remains disconnected, and the hose that was connected to the outlet of the fuel valve is now connected to the outlet of the fuel filter. The arrows show the flow of fuel from the fuel tank to the carburetors, bypassing the valve entirely.
5) Disconnect (pull off) and plug the hose that supplies vacuum to the fuel valve.
The fuel valve is operated by vacuum sourced from the engine. Because your fuel valve has failed, it is possible that there might be an open path between the vacuum source hose and either the outlet or inlet of the failed fuel valve. The presence of a large vacuum leak like this will degrade engine performance, so, you should plug the vacuum line, just to be on the safe side.
As we know, the ST 1100 has zillions of little bolts holding Tupperware panels in place all over the bike. Locate a bolt that you think you can live without, remove it, and stuff it into the end of the vacuum line. That will prevent any vacuum leaks.
The procedure described above will get you back on the road again with a fully-functional motorcycle. Provided you have the 3 necessary tools (Phillips screwdriver, hex-key for the Tupperware false fuel tank, and a pair of pliers for squeezing the clamps on the fuel hoses), it only takes about 30 to 45 minutes to complete this roadside repair.
I don't know why the motorcycle has this fuel valve. My valve failed in May, I carried out the bypass in May, and rode for another 6,000 miles that year. When I dropped the bike off at the dealer for winter storage and maintenance, I had them replace the fuel valve. I didn't encounter any problems that summer riding around with the valve bypassed.
There are a number of threads here in our forum that discuss how to repair and/or rebuild the fuel valve once you get back home. Here are links to them:
ST1100-Fuel Shutoff Repair
ST1100 Vacuum Fuel Shutoff Repair Sequence
Vacuum Fuel Valve Rebuild
Michael
The valve usually doesn't fail abruptly and bring you to a halt. Instead, you'll experience a loss of power, as if not enough fuel is getting to the engine (which is exactly the cause of the problem). The bike will decelerate, and after a little while, you will be able to accelerate again, only to have the bike once again lose power... the cycle repeats about once every 3 to 5 minutes.
The purpose of this article is to explain how to do an "emergency bypass" of the fuel valve in case you encounter this problem when you are away from home. It's a simple fix that only requires a Phillips screwdriver, a hex-key, and a pair of pliers.
The fuel valve on my ST 1100 failed way back in 2005. At that time, I did a write-up with pictures on Steiner's My-Mc forum, but that forum has since shut down. So, here's a repeat of the post I made just after carrying out my emergency roadside repair.
1) Remove the seat, the right side cover, and the false fuel tank cover.
You might have to remove the left side cover to get the false fuel tank cover off - but, maybe not.
To remove these covers, you need the Phillips screwdriver and the hex key.
The fuel valve is on the right side of the motorcycle (see the red arrow).
2) This is what the valve looks like once you get the covers off.
Fuel enters from the hose in the bottom left of the picture, goes through the filter, makes a 180° turn, goes through the fuel valve, then exits forward into the carburetors.
3) The 'emergency bypass' is really simple to carry out: follow the 3 steps in the picture below.
First, disconnect the hose that delivers fuel to the carburetors. That hose is partially hidden in the photo below.
Next, disconnect the hose from the forward end of the fuel filter.
Finally, connect the fuel delivery to the carburetor hose to the forward end of the fuel filter.
4) When you have finished, it should look like this:
The lower end of the 180° turn hose remains disconnected, and the hose that was connected to the outlet of the fuel valve is now connected to the outlet of the fuel filter. The arrows show the flow of fuel from the fuel tank to the carburetors, bypassing the valve entirely.
5) Disconnect (pull off) and plug the hose that supplies vacuum to the fuel valve.
The fuel valve is operated by vacuum sourced from the engine. Because your fuel valve has failed, it is possible that there might be an open path between the vacuum source hose and either the outlet or inlet of the failed fuel valve. The presence of a large vacuum leak like this will degrade engine performance, so, you should plug the vacuum line, just to be on the safe side.
As we know, the ST 1100 has zillions of little bolts holding Tupperware panels in place all over the bike. Locate a bolt that you think you can live without, remove it, and stuff it into the end of the vacuum line. That will prevent any vacuum leaks.
The procedure described above will get you back on the road again with a fully-functional motorcycle. Provided you have the 3 necessary tools (Phillips screwdriver, hex-key for the Tupperware false fuel tank, and a pair of pliers for squeezing the clamps on the fuel hoses), it only takes about 30 to 45 minutes to complete this roadside repair.
I don't know why the motorcycle has this fuel valve. My valve failed in May, I carried out the bypass in May, and rode for another 6,000 miles that year. When I dropped the bike off at the dealer for winter storage and maintenance, I had them replace the fuel valve. I didn't encounter any problems that summer riding around with the valve bypassed.
There are a number of threads here in our forum that discuss how to repair and/or rebuild the fuel valve once you get back home. Here are links to them:
ST1100-Fuel Shutoff Repair
ST1100 Vacuum Fuel Shutoff Repair Sequence
Vacuum Fuel Valve Rebuild
Michael
