Rough running

[stevedore]

Just put a new battery in the bike. Had to replace one quick disconnect as it broke during disassembly. Other than that nothing changed. When i started the bike it ran rough, back fired and surged until I gave it more gas then it would take off. Could I have reconnected the electric to the fuel pump incorrectly? Both cylinders are working but it seems erratic and if I blip the throttle at idle it coughs. Please tell me i didn't ruin the EMC by connecting the fuel pump connector backwards.

[Sunbeemer]

Don't worry, I don't think you can connect the fuel pump connector backwards.
The most common thing to occur after taking the tank off that causes rough running is the (usually right-side) throttle cable gets pulled out of the adjuster screw (mounted on the throttle body above the cable wheel) so it rests on top of the rim of adjuster. Just reseat it into the recess in the top of the adjuster (and check both sides while you're at it) and you'll be smooth again.

[CycleRob]

stevedore,
You got tripped up by the right side throttle cable that got pulled up-n-out of the adjuster ferrule when you were struggling with the QD's. Look at the throttle cable and make sure it's centered and seated inside the adjuster ferrule. Watch it as you wind the throttle to the full throttle stop and you'll see it full seat itself.

You did not mention resetting the Motronic computer's TPS parameter's after the new battery install. It must be performed for the bike to run right from the start. Here's how:

--Remove fuse #5 from the left, wait 10 seconds then replace it.
--Key and kill switch ON, gearbox in neutral. Do not touch starter button!
--Twist throttle from idle to full throttle 2 times.
--Turn off key -or- start the engine.

Do these 2 procedures and you'll be right again. Be aware that the bike will not immediately have full engine braking on downshifts until the Motronic "learns" and "trims" the new fueling/ignition map. The throttle response and cruise fueling will also will be "trimmed" as you ride the bike and gradually improve. This whole process usually goes unnoticed unless you're focusing on it. It's not a flaw . . . every computer controlled fuel injected vehicle needs to perform this same data map trimming routine. It should be all set after your 1st full, hot engine ride.

.

[stevedore]

stevedore,
You got tripped up by the right side throttle cable that got pulled up-n-out of the adjuster ferrule when you were struggling with the QD's. Look at the throttle cable and make sure it's centered and seated inside the adjuster ferrule. Watch it as you wind the throttle to the full throttle stop and you'll see it full seat itself.

You did not mention resetting the Motronic computer's TPS parameter's after the new battery install. It must be performed for the bike to run right from the start. Here's how:

--Remove fuse #5 from the left, wait 10 seconds then replace it.
--Key and kill switch ON, gearbox in neutral. Do not touch starter button!
--Twist throttle from idle to full throttle 2 times.
--Turn off key -or- start the engine.

Do these 2 procedures and you'll be right again. Be aware that the bike will not immediately have full engine braking on downshifts until the Motronic "learns" and "trims" the new fueling/ignition map. The throttle response and cruise fueling will also will be "trimmed" as you ride the bike and gradually improve. This whole process usually goes unnoticed unless you're focusing on it. It's not a flaw . . . every computer controlled fuel injected vehicle needs to perform this same data map trimming routine. It should be all set after your 1st full, hot engine ride.

.

Thanks to all for the response. I'll check the throttle cable and reset the TPS. I did not do that after the install. Fingers crossed but that would explain a lot.

[stevedore]

stevedore,
You got tripped up by the right side throttle cable that got pulled up-n-out of the adjuster ferrule when you were struggling with the QD's. Look at the throttle cable and make sure it's centered and seated inside the adjuster ferrule. Watch it as you wind the throttle to the full throttle stop and you'll see it full seat itself.

You did not mention resetting the Motronic computer's TPS parameter's after the new battery install. It must be performed for the bike to run right from the start. Here's how:

--Remove fuse #5 from the left, wait 10 seconds then replace it.
--Key and kill switch ON, gearbox in neutral. Do not touch starter button!
--Twist throttle from idle to full throttle 2 times.
--Turn off key -or- start the engine.

Do these 2 procedures and you'll be right again. Be aware that the bike will not immediately have full engine braking on downshifts until the Motronic "learns" and "trims" the new fueling/ignition map. The throttle response and cruise fueling will also will be "trimmed" as you ride the bike and gradually improve. This whole process usually goes unnoticed unless you're focusing on it. It's not a flaw . . . every computer controlled fuel injected vehicle needs to perform this same data map trimming routine. It should be all set after your 1st full, hot engine ride.

.

Thanks to all for the response. I'll check the throttle cable and reset the TPS. I did not do that after the install. Fingers crossed but that would explain a lot.

Hats off to you guys. I was really worried. However, I had to reset the right side throttle cable in the seat and the TPS as per instructions above. She fired right up and ran like a watch. Thanks again all. I guess I owe you a beer or six at least.

[Sunbeemer]

Glad it worked out. Same thing happened to Ewan (in Russia) during "The Long Way Around" tour!

[CycleRob]

The right side cable getting pulled out of the adjuster ferrule socket would not be a common occurrence IF the BMW engineers had made the right side throttle cable just an inch (25mm) longer!! It would then be much less likely to be pulled "out" because of the slightest unintentional sideways deflection of that cable.

Anytime anyone removes the fueltank, they MUST check the full insertion of the right side throttle cable into the adjuster ferrule after the tank is fully installed. Then turn the throttle to the full throttle stop to confirm the simultaneous "tap" of both TB spools hitting the full throttle stops. It should sound like only one tap, coming from 2 different locations.

If you remove a battery main cable or the #5 fuse for any reason, you should reset the Motronic as described above.