Rough Running

[taosports]

Background : I have a 2004 1150R (dual spark) , bought new 5 years ago. It has 60,000 miles of trouble free riding except for an issue with the over zealous factory tightening of the wiring looms under the headlight. Since the 6,000 mile checkup, I've done all of my own maintenance on the bike including the ABS brake fluid bleed and I even change my own tires...so I enjoy working on this bike.

The Issue : Recently, I noticed a flat spot when I accelerated under heavy throttle at @ 5- 6,000 rpms. It occurred occasionally at first and then got progressively worse. Other than that, the bike ran well. It Idled fine with no surging. Problem only came up when I had a heavy extended throttle pull. That was a few thousand miles ago. Now, the bike was showing crankiness starting, rough idling and just recently surging along with the flat spot.

The Cause (?) : I figured it could be due to any number of things - the plugs, the valves, TB balance, the air filter, the fuel filter and probably a whole lot more but I started with the simple fixes first. I replaced the plugs, fuel and air filters and did a careful valve adjustment and TB balance, none of which helped. So, back to the head scratching.

The Fix : I was reading about the issues others were having with symptoms like mine and discovered that faulty ignition coils were a source for some. Bingo! That was it for me. Replaced both since I wasn't sure if I had one or two failing coils and figured it prudent to replace both at 60,000 miles. Bike started right up without hesitation, idles smoothly, with no surging in the lower gears and no more flat spot in acceleration.

Here's a photo of the old and new side by side. Note the grey top on the new coil. Has a different part number also. BMW 12137680644.



Anyway just wanted to pass this on to others experiencing similar issues. Check those ignition coils!

[sweatmark]

Michael,

Thanks for taking the time to describe both the problem and solution to your bike's condition. Great info.

It's the quality of R1150R owners and the quality of the bike's utilitarian performance the makes this group and the machine so exceptional. And that's in spite of imperfections due to BMW mis-engineering.

Thanks again.

[DMM]

Michael,
What did the coils cost you? I can't remember the exact cost, but I could swear that I paid around $100/each just over a year ago.
David

PS - Ditto for what Sweatmark said. This on-line community makes owning a BMW a shared adventure.

[boxermania]

Notice that the white part on the new coil stick is longer than the old one......so it appears that the roduct has been re-engineered with hopes of added durability.

Now I have to modify my earlier statement regarding the TB's synch as the item that will affect most the smooth running of the bike and have to add bad stick coils as another source......

[taosports]

Michael,
What did the coils cost you? I can't remember the exact cost, but I could swear that I paid around $100/each just over a year ago.
David

Full price is $122. per stick. So close to $100. if you order through Chicago BMW.

[taosports]

Notice that the white part on the new coil stick is longer than the old one......so it appears that the roduct has been re-engineered with hopes of added durability.

Think they're identical in size. Since the new stick is closer to the lens, it appears bigger. However the top of the new stick is definitely made of a different material - hopefully one that can withstand the heat better.