First sorry for my english.
I have a 85 k100 lt with 26000 miles on it the bike was sitting for 3 years so wen i purchase i change the oil + filter new gas filter and new air filter now for the problems
1.-The bike start and die even with full choke, you need to hold the gas a little for the engine not to stall.
2.-Take about 20 mints for the engine to be hot and not stall wen u release the trotte.
3.-On the first road test wen you reach 2000 rpm i have some back fire.
4.-The reaction of the bike its very slow and for me to start moving i need to put the engine at 3000 rpm if not you will hear some noking.
Any ideas are welcome this is my first bmw bike i only have japanise bikes before and i am used to just start and after a min or 2 go.

Thanks in advance.

Maxi

well it runs at least...... woohoo ....

gaxi just some additional questions .......

1> did you empty the fuel tank completely ? clean up ...and then fill with fresh fuel, what fuel are you using ?

2> did you think to replace or clean up the spark plugs and check the connections /leads ?

3> whilst doing that did you check the connections to the high voltage coils behind the black cover on the riders left hand side just below the side cover


not sure what enviromental problems could be in your area but, have you looked at some of the electrical connections .....you are looking for anything that resembles powdery corrosion in several places some under the tank ..... check as many of those that you can ...dont forget the computer that sits under the seat. could be just a remove connection and then plug it back in ... that may help

maybe you can post some pictures for us .....were always interested to see different things ....and members rides

there are some great tutorials on this site
good luck

Clean all the electric connectors, particularly the ground connections under the fuel tank and next to the coils.
Your problem could well be due to an air leak, have a look at some other posts, testing with brake cleaner will tell.
Otherwise a quick check; if the motor runs and you take of the filler cap for the crankcase (assuming you have it properly closed when running) you should hear a destinctive difference in the engine sound. If not you have a massive airleak.
False air (air leak) after the air mass sensor allows unmetered air to be drawn into the engine and results in a poor running bike as the mixture is too lean.

Yes sounds like a vacuum (air) leak to me as well. If that is true, it will be on the left side of the engine in the area where the throttle bodies (TB's) are. There are two sets of rubbers above and below the TB's, as well as the crankcase vent tube just to the right of the TB's as you look it from the side. This is a right angle looking tube. Also the little vacuum caps on the TB's shold be checked. My '85RS had a cracked TB upper rubber and vent tube. This allows air into the mixture after the air flow meter and makes the mix lean and rough running. Causes backfires too.

As ReneZ said, with the bike running, spray some brake or carb cleaner on these rubber parts one at a time. If the engine begins to smooth out, it's because it's sucked in some of the flammable spray through the rubber cracks and burning it. That will be the problem part.

Adding to the above list: vacumtube to the fuel pressure regulator, connected at TB stub cyl. 4.
(where it is rubber cap on the 3 others).

Inge K.

And on the very early ones the vacuum line to the vacuum switch from unit 1.