BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

I think I have an ignition problem and I feel that I narrowed it down to a bad ignition coil. Listen to my troubleshooting and see if you come up with the same as I do on this.

I have a 2004 "Two Spark" r1150r, which two spark means four spark plugs - each cylinder has two plugs (maybe a German way if counting), a primary plug on the side and secondary on the bottom. Over the weekend I was caught in a bunch of rain (nothing hard, just light annoying rain) and that's when I noticed it running a little funny. At the same time I noticed an ignition noise in my headphones, which I've never heard before. Anyway, I figured it was due to the rain and expected it would go away when things dried out (I've been in much harder/longer rain before). The next day, still the same.

Here are the symptoms: When the bike is cold it barely wants to stay running, after it warms up it will run but the idle is under 900rpm, and very rough. While at speed, trying to accelerate you can feel it surging and has a lack of power. Also some minor backfiring when decelerating.

History: My bike has just turned over 39000 miles and has run great. I recently completed the 36k service myself (beginning of April) and it has been running smooth.

I pulled the plugs and they look fine (I replaced them at the 36k service). I thought it could be a failed plug since they were new and swapped the plugs out one at a time with an older plug and no difference. Then I tried pulling the secondary plug wires off (one at a time) to see if it made a difference. Here are some scenarios:

1. pull the right cylinder secondary plug wire off with the bike running = no affect
2. pull the left cylinder secondary plug wire off with the bike running = engine sputters and dies.

I swapped primary coils (the primary spark plug 'boot') and the above observation moved to the other cylinder.

This leads me to believe that the left cylinder was running on one plug, the secondary. When that cylinder's secondary plug wire was pulled, the engine died. By swapping the primary plug coils, the problem seemed to move with the coil, making me think that the coil is bad, not the signaling going to it. Does everyone agree? Disagree?

The coils MSRP at $80 (oddly though, Battley wanted $90 for it). The bummer is nobody stocks them and I was planning on a camping trip this weekend!

Help!

John, isn't your bike still under warrenty, or did I miss something??

I wish it was under warranty - I have over 39000 miles - the warranty expires at 36000. I tried calling a few dealers today and nobody stocks the coil. My dealer is open tomorrow so I'll see what they can do for me. I'm not too concerned about the cost (MSRP is around $80) of the part, but more of availability. I was kind of planning on an overnight camping ride this weekend. I won't do the ride if the bike is not running good.

John, I hope that coil doesn't interfer with your riding plans for the holiday weekend.

mac

Morton's came through! They have two coils in stock, when NOBODY else does! Even Chicago BMW doesn't stock them. I'll probably pick one up tomorrow and be ready for this weekend.

John. May be too late but here's one at BeemerBoneyard

http://www.beemerboneyard.com/12137671712.html

Good detective work, John. Keep us posted.

1. pull the right cylinder secondary plug wire off with the bike running = no affect
2. pull the left cylinder secondary plug wire off with the bike running = engine sputters and dies.


If you can pull the wire off the right cyclinder and there is no effect then I would say that wire was not doing anything. So that could be the bad one. Before swaping the coils you might want to swap the wires sometimes they can breakdown inside, and they are going to be cheaper. So you could buy one new one and replace the old ones in turn untill the fault disaperes.

leno wrote:1. pull the right cylinder secondary plug wire off with the bike running = no affect
2. pull the left cylinder secondary plug wire off with the bike running = engine sputters and dies.

If you can pull the wire off the right cyclinder and there is no effect then I would say that wire was not doing anything. So that could be the bad one. Before swaping the coils you might want to swap the wires sometimes they can breakdown inside, and they are going to be cheaper. So you could buy one new one and replace the old ones in turn untill the fault disaperes.

After thinking about the difference of pulling the two plug wires and the different results made me come up with this:
The secondary plug was put there to assist the burn process, not be the main source so *technically* you should be able to pull both secondary plug wires off without any noticeable difference. Now if the primary plug was not firing on one cylinder and it was running on the secondary plug, then pulling the secondary would cause that cylinder to be completely dead, and stall the motor. Which is what happened. It took a little thinking on my part (I should recover from thinking that hard soon) to come up with that prognosis.

I ordered a new coil (actually my dealer had a couple in stock) and put it on yesterday and voilà - my power has been restored. I'm glad that was the problem, and now I can get back to my regularly scheduled rides.

Glad to hear all is well!!

R4R&R wrote:It took a little thinking on my part (I should recover from thinking that hard soon) to come up with that prognosis.

Wait! While you are at it, can you please think of a way to make my dealer/mechanic think that hard ? Money alone doesn't seem to do it.
Congrats for figuring out that issue and thanks for sharing.

Bravo! Good job.