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Will a hard drop cause this?


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The wife and I did a 3 hour ride yesterday. Bike ran perfect. After unloading my valuable cargo I had a complete brain f#*t (failed to put down the kick stand) and dropped the bike, hard - on it's left side.


Now on full throttle acceleration the engine starts missing at about mid-range but seems to clear up by the time it gets to redline. This happens in 1st, 2nd and 3rd gear.


Any ideas?

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bushmanstan, lots of possibilities on your problem..


I would put either a loose (or broken) L/H stick coil or an oil fouled lower L/H spark plug at the top of the list as a place to start looking..


Remove both L/H spark plugs & look for any coil damage,, then look for signs of oil fouling..


Sometimes when they sit on their side for a while oil will run into that low cylinder..


If that isn’t the problem then you will need to go through the basics & check other thing in the ign system & fueling system..




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It's the "sheath" that snaps onto the spark plug--hi-tension spark coil built right into it. Sits right behind that arrowhead-shaped plastic cover on each valve cover. You can remove that cover easily and eyeball the stick, just grab the skinny rear part of the plastic cover and pry away from the cylinder--it will pop right off--won't break. If the plastic cover isn't smashed in, I kinda doubt the drop wudda messed up the coil. But it does sound like a coil issue--or spark plug--either side. But Twisty may know something I don't.


Edit: don't try to pull the stick coils loose unless you have a tool for that purpose--they will break. Some have used screwdrivers to do this, but I don't chance it. Here's where you can get a removal tool-->> http://www.marcparnes.com/BMW_Plug_Tool.htm Also--to remove the sparkplugs, you'll need a deep socket that has been ground down a little on a bench grinder so it doesn't stick inside the hole where the plugs are.

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Be sure to remove the wire leading to the stick coil before removing said stick coil (very fragile).


Actually you may want to check these first. If you've partially dislodged the plug going into the coil you will get the same type of behavior. Or if you forget to get them properly snapped in after changing plugs DAMHIK. :grin:

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Thanks, I've ordered the Marc Parnes tool and will check that connection in addition to inspecting the plugs ASAP.


I appreciate all the helpful input from each reply.



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You might also, before pulling a spark plug, try tightening it a little to see if its possibly loose. This can also cause the problem due to intermittent ground. Be sure to use correct torque values when tightening the plugs.

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  • 4 weeks later...



Your first guess was correct; the stick coil had become partially dislodged. When I took the spark plug cover off and pushed on the stick coil it moved inward slightly.The bike runs fine now.


Thanks again to all who offered advice.



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