K1200LT Shuts Down mystery

[mark1161]

Hey guys,

I have a 2000 K1200LT with 23k on the clock. Last week I was traveling to the NJ shore, and the weather was hot. Bike was not overheating, and the temperature gauge was exactly in the middle. I had a little more than a quarter tank of gas, and I had no issue traveling at a highway speed of 65 mph. The engine was sounding great, and I have had no mechanical issues, other than replacing the fuel pump, with the bike since I bought it at 14K. At the bottom of the exit ramp, the bike shuts off and I was able to roll to a safe spot on the side of the road. At first I thought, somehow, the gas gauge was wrong, which has never been a problem, so I put in another gallon of gas. The bike would start but only for about 5 seconds and then shut down again. I was able to park it at a local Public Storage and came back the next week to have it towed to my mechanic. Of course, the bike started right up and stayed running. It has been at my mechanic's shop for the last week, and he also can't get it to repeat the problem despite running it for hours. Does anybody have any clues of what I was experiencing that we might track down to figure this out?

Thanks for any help.

Mark

 

[pwhoever]

No experience with a BMW but I had similar experience years ago with a Honda GL1500 Goldwing and I can tell you numerous tales of others that had same experience. When the Goldwings would get older and weather conditions were in the upper levels of ambient heat, along with a fuel level down to near 1/4 tank, the bikes would shut off. They were being starved of fuel.

The problem was that the pumps were getting weak and overheating and then couldn't supply enough fuel. They would work just fine when the fuel level was at 1/2 to full. But get to 1/4 of a tank and high ambient heat conditions and then they would still pump some, just not enough. They would need more fuel in the tank to keep them from overheating. This was easily tested by using an extra length of spare fuel hose attached to the output of tank, holding the hose about head level in a glass jar and jumpering the fuel pump from battery. You could then observe that the flow was weak. Also once the fuel pump had a chance to cool down, it would start working again. The fix was to replace the fuel pump. Have the mechanic test the bike after it's been out in the heat for a bit and especially when the fuel level is down around 1/4 tank and see if the problem returns.

I know you mentioned that you already replaced the fuel pump but how long ago? If it was some time ago, it's possible that the replacement is now starting to go bad.

 

[mark1161]

Thanks for your detailed response. The fuel pump was just replaced 3000 miles ago and hadn't been a problem up until the bike shut down. However, I don't recall running the bike down to about a 1/4 tank. I usually refill before it gets that low, which is about 100 miles between fills. I will let my mechanic know your answer.

 

[Papa Zook]

Most common 2000 BMW 1200LT randomly stalling issue causes:
1-Water in the Gas:
Was it recently filled up? Pour some gas dryer into the tank, Isoheet in the red bottle or Heet in the yellow bottle.
2-Charcoal Canister Clogged:
Has your trike had the charcoal canister removed? If not, it could be that the charcoal canister is stopped up and you're creating a vacuum in the tank. Open the tank filler cap and if you hear a "whoosh" that's your problem. Do a canisterectomy (remove it).
3- Fuel Pump:
Look into the filler cap of the fuel tank and turn the key on so you can hear the fuel pump running. If you can see movement of the fuel in the fuel tank, you've probably got a ruptured fuel line between the fuel pump and the filter.
4-Crankshaft Position Sensor:
Heat is a known killer of the BMW 1200LT Crankshaft Position Sensors and is the most common contributor to their failure.

 

[mark1161]

Thank you for your detailed response. I will investigate all of these possible solutons.

 

[Gorilla]

All the above but did you change the fuel filter when you changed the pump?

 

[mark1161]

Yes, the fuel filter was changed, but I am not sure the fuel lines were changed, which is another rabbit hole I have to down. Thanks for the suggestion.