Stick Coil Sticks it to me

[realshelby]

My '04 RT with 44K had not been herself for a few months it seems. Starting usually required two to three tries and it just did not seem to run like it did. A little surging that I NEVER had before, having to rev the engine and slip the clutch more that I used to. Two tankfuls of gas back it was to the point it sounded bad at idle and was really surging bad. I thought it must be bad fuel/clogged injector.

 

I changed the primary plugs because they are easy. No change, old plugs looked good. Sooooo...off comes the tupperware. Up on the lift I start looking and testing for vacuum leaks, wire issues, anything. I installed an inline plug tester on all 4 plugs. Seems to be firing at all 4 plugs. Must be a fuel problem, I pull the injectors and note that it will run with the injector out of the throttle body! Both have nice spray patterns. I clean throttle bodies. I notice the right header is red, even though I keep a high velocity fan in front of bike. That would indicate unburned fuel in that header. Back to ignition. I pull the primary stick coil and put in a spark plug and ground it. No problem, it runs and spark shows good. I repeat this on other 3 plugs. There is a difference in effect between the primary and secondary plugs being "disabled", but at idle the difference was not as obvious. I then checked compression, 160 lbs + or - 5 lbs so that is ok. I hooked up the manometer to check on balance and this is what helped me find the problem!

With the throttle lock on to hold about 3000 rpms I tried pulling off the secondary plug caps for a moment. VOILA ! Pulling the right secondary and the engine obviously was not firing on the right side from the primary coil!

I went to the BMW dealer and gave him $116 for a stick coil. What a difference. Starts like it should, no more surge, much improved power and response. The coil must have been slowly going bad, I would have noticed that much difference instantly otherwise.

Hard to believe if you could have seen the spark coming from that coil, it simply would not fire properly under combustion pressure. I suppose it could be that it was jumping spark to the valve cover. I coated it heavily with dielectric grease to see if that helped but it did not.

I hope this long post helps someone else...I was really surprised at the outcome.

[ProductUser]

I replaced my stick coils some time ago. Like you said, it seemd to fail slowly and it took me a while to find the bad coil. I also replaced the secondary plug wires afer 50k miles due to some harsh riding conditions and for good measure. The secondary plug wires were very brittle, too.

 

Tony

[Justin_B]

I'm a newbie to Oilheads but what would be wrong with doing away with these "stick coils" and running a Dyna coil of the proper resistance?

[Ken H.]

I'm a newbie to Oilheads but what would be wrong with doing away with these "stick coils" and running a Dyna coil of the proper resistance?

How are you going to trigger, time it?

[Justin_B]

That's why I'm asking, the R1150 RT repair manual I downloaded makes no mention at all of the secondary plug system. How are the "stick coils" triggered?

[Fugu]

That's why I'm asking, the R1150 RT repair manual I downloaded makes no mention at all of the secondary plug system. How are the "stick coils" triggered?

 

The secondary plugs (on the bottom of the jugs) are fired (not triggered) by a conventional coil that's up under the tank.

 

The primary plugs have the stick coils.

 

I *THINK* that the HES triggers both by sending a signal to the Motronic computer about the position of the crank, which computer in turn tells the respective coils to fire the plugs.

 

When I had stick coil issues I couldn't find data on testing them other than "plug into BMW shop computer MoDiTec" so I think for starters your issue would be sorting out how to get the Motronic to talk to an aftermarket coil, etc.

 

The question then would be WHY?

 

Just replace stick coils if/ when they fail.

 

 

[Justin_B]

It's always nice to have alternatives...

[Clive Liddell]

Of course my bikes don't have secondary plugs BUT - I have seen that on the factory dual plug arrangement the timing between the primary and secondary plugs varies (and differs) a lot I presume depending on various engine parameters.

 

As I recall, the "California" conversion to 2 plugs per cylinder did not have this "factory" timing setup.

[Boffin]

Of course my bikes don't have secondary plugs BUT - I have seen that on the factory dual plug arrangement the timing between the primary and secondary plugs varies (and differs) a lot I presume depending on various engine parameters.

 

As I recall, the "California" conversion to 2 plugs per cylinder did not have this "factory" timing setup.

 

As I understand it, that only applies to the 1200 motor, with the 1150 sparking all four together.

 

Andy

[DonW]

OK, here's another possible goofy question. I see MUCH less expensive stick coils for other than BMW's (eBay, etc.). Any chance any of them would work in a dual spark R1150?

 

I pride myself in NEVER having gone to the dealer for service. The ridiculous amount of time I've wasted will no doubt be added to my total time on earth... just like that old saying about "the time spent repairing your boat..."

 

[Justin_B]

If all four fire together (i.e. regular BMW boxer wasted spark ignition scheme) I can't see a good reason (yet) not to use, say, a Dyna dual coil of the proper resistance as long as suitable HT lead could be sourced/fabricated.

 

Don, this desire for "cheaper alternatives" is the ingrained Airhead mindset in us attempting to exert control... ;-)

[DonW]

We don't refer to ourselves as "cheap airhead bastards" for nothing...

 

But, I re-read "Zen and the art of MC maintenance" recently (read it the first time in about 1972), and I'm surprized at how far I've evolved in my ability to enjoy self sufficency...

[TyTass]

I hope this long post helps someone else...I was really surprised at the outcome.

I have been experiencing similar issues of slowly increasing frequency and severity for many months now. A couple of dealers have attempted repairs that did not fix the problem ... though admittedly it as started off with very intermittant symptoms. This past weekend it got positively terrible at the RCR in WV.

 

I believe this thread is going to help me troubleshoot this week. I'll let you know how it turns out.

[DonW]

I continue to have more vibration than I think is normal at RPM's above 5K. Was pretty convinced it must to a bad stick coil. Luckily, have a nearby buddy with a 2004 GS, who let me borrow both his stick coils for a day. Substituted them in every possible combo, and made no difference. So the good news is- I didn't sepnd $200 on un-needed coils. The bad news is- I still don't know what's wrong...

 

Don

[Haynes]

Stick coils cured my worries. Occasional rough idling became an issue and sometimes the bike was hard to start. I didn't bother to check which stick coil was to blame; I replaced both.

[Aussie Rider]

Stick coils cured my worries. Occasional rough idling became an issue and sometimes the bike was hard to start. I didn't bother to check which stick coil was to blame; I replaced both.

 

I may also be up for a new stick coil, can you please tell me where you got it and what cost?

 

[jblaze5779]

Chicago BMW 97 bucks each

 

edit: I just noticed your location.

[realshelby]

Craig, the "secret" to finding the problem was having the rpm's held at 3K or so and momentarily disconnecting the SECONDARY plug cap with a pair of pliars. Compare the difference in rpm drop and smoothness between the two cylinders. The difference was VERY noticeable on my engine. What was confusing up to that point was that I could remove the stick coil ( leaving the spark plug in the head ) and put a spare spark plug in the stick coil. Holding it against ground it would fire what appeared to be a normal spark. It just would NOT fire properly under load.

[TyTass]

Thanks. I'll probably won't get to this until this weekend. My guess is that I'll have similar findings.

[philbytx]

Just get a single spark.....dual spark heads are just a PITA and, IMHO, don't offer much (if at all) over the single spark motor.

 

Surge? What Surge???? Both my R1100R and R1150RT run just great with an anal valve job and a TBS

[TyTass]

Yeah, Phil! That's how I'll fix my 1150 idle issue. Replace it with an 1100!

[philbytx]

Easy Peasy mate :grin

Although an R1150RT single spark would be better though

 

[TyTass]

Yes, there is that!

[4wheeldog]

Just get a single spark.....dual spark heads are just a PITA and, IMHO, don't offer much (if at all) over the single spark motor.

 

Surge? What Surge???? Both my R1100R and R1150RT run just great with an anal valve job and a TBS

 

+1. I believe many "Surge" issues continue because of dealer's tuning requirements being insufficient. My '02 has always run smoothly, just not much possible gain for the complication of stick coils possible. I also believe that the spark plug specified by BMW is not the most appropriate. Just sayin'.

[Bill_Walker]

I hope this long post helps someone else...I was really surprised at the outcome.

 

Thanks! You really helped me. My bike had the same symptoms. I had also tried a plug tester and seen spark on all four. After reading this, I tried pulling the secondary leads, and found that when I pulled the right one, I suddenly had a surprisingly smooth-running thumper! One new stick coil, and voila, it starts and runs much better. 45K miles at the time. There's still more vibration then I recall, though, so I might replace the left one, despite the expense, on general principles.

[Bill_Walker]

Or, now that I read farther down, I'll try your load test trick.

[Kozmo659]

This thread saved me a ton of time.

 

I recently took a trip with friends from Md. to Tennessee. The RT was not running right on our trip. It was hard to start and missing when it was cold, and once it warmed up it was hesitating and surging - but at least it was running. My motto is to not f--- with it if it is running and I am far from home. Last Thursday I finally pulled the lower fairing and checked the plugs - they all looked "normal" and they were all firing. WTF...

 

Because it is a 2004 RT wiuth the Dual Spark ignition - I could tolerate the issue while we were on the road - it was only running rough, not completely missing.

 

After much reading on forums I landed on this thread. So - off to the dealer I rode, and picked up a new stick coil for two-dang-much-$.

 

On Saturday, I put the new coil in the left side and rode for a day - No change. So, yesterday I put the original coil from the left side into the right cylinder. Man what a difference - it is running like new again! Friggin' thing failed right on schedule while we were on the Tennessee trip. I am gonna pick up another new one next time I go to Bob's BMW, or when it starts to run rough again - whichever comes first.

 

Thanks for the post!

[TyTass]

I got delayed from working on my bike for about a month due to way too much overtime and a few weekends of non-bike travel. After reading this post I too was convinced a stick coil would solve my problem. One day during my running back and foth to the airport I picked up a stick coil from Bob's BMW (and paid way too much for it - should have ordered from the link here, especially given my delays - OFW!).

 

Today I pulled each connection in succession. Indications:

• Left Secondary pulled - Lower than normal idle, but not ranging intermittantly
  
• Left Primary pulled - Idle ranging dramatically and cut out a time or two. When idling "normally" idle was 950-ish.
  
• Right Secondary pulled - Idle low again, but still ranging intermittantly
  
• Right Primary pulled - Bike sounded like my old Thumper! But intermittantly!

That confused me a bit. Could I have two bad secondaries? So I tried the new coil on each side (secondaries). Indications:

• 
   
  
• Right Secondary replaced - Idle was right at 1100 but the ranging was still present intermittantly.
  
• Left Secondary replaced - Idle low at 950 but perfectly smooth. Off idle was also smooth.

 

So I read that as having two bad coils but with different types of failures. Anyone disagree?

 

If not, this time I'm ordering the coil from the link someone posted previously and saving myself some money.

[T__]

Craig, disconnect both primaries & run it (see if it idles & runs on both sides),, then reconnect the primaries & disconnect both secondary’s & see it will idle & run on both sides.. That might shed some light on what you are dealing with..

 

On the stick coil it just kills that spark plug,, but on the plugs with plug wires & common coil remember the spark plug on one side is the ground path for the plug on the other side.. Don’t JUST disconnect a conventional plug wire,, instead either leave it connected & short it to ground or if disconnected be sure to use a jumper wire & ground the non connected wire to the engine case..

 

Twisty

 

[realshelby]

Craig, do you have a way of holding the throttle to keep rpms around 3-4K? While holding those rpms try disconnecting the secondary plugs ( and/or primary ). That made all the difference in singling out my faulty coil.

[TyTass]

Thanks for the quick responses.

 

Terry, when I said off-idle I was talking about holding it at about 3500 rpms. Those were my indications above.

 

Twisties - did what you said and here are my new indications ...

 

Disconnected both Primaries. Indications: Ran like a poorly tuned thumper.

 

Put the new coil in left secondary. Indications: Unchanged.

Put the new coil in right secondary. Indications: Bike ran very smoothly (at idle and off-idle).

 

Disconnected both Secondaries. Indications: Bike ran well off-idle (3500). Normal idle was low again 950), and it stumbled a bit (though nothing like it did as described in my previous post).

 

So, I now KNOW I had a bad right secondary stick coil. But now I'm not sure about the low idle and "stumbling" issue when running on the primaries.

 

How do I isolate further from here?

[TyTass]

Oh yeah, one more indication. with the new stick coil on the right side, my headers didn't end up super hot.

[T__]

Craig, the lower idle on just the primaries is probably about normal as you lost the 2nd flame front.. I don’t know about the stumble though.. Might be normal with just one plug per cylinder operational.. Could also be a computer learned off set in the fueling tables due to that misfiring coil.. Or the 02 sensor a bit off..

 

Take it out & ride it awhile & see how it runs if it runs good & clears up then probably all OK..

 

 

Twisty

 

[TyTass]

Thanks. I was actually surprised that it ran so perfectly off the secondaries from my previous indications. It was nice to hear.

 

You might be right about the computer learning to offset this problem. I've been dealing with this for about a year - starting off as a minor intermittant problem that progressed to full-on PIA more recently.

 

Do you recommend I resync TB?

 

Thanks. For all the help you guys. FYI: Two dealers failed to correctly isolate this problem (but then again it was intermittant).

[T__]

Craig, while it never hurts to confirm the TBI sync whether or not a cylinder in firing should not effect the TBI balance as that is not power measurement it is just the measurement of air pressure drop across the throttle plate area of the TBI.

 

Twisty.

 

[TyTass]

Duh! Of course, you are correct.

[Bill_Walker]

Craig, one of us is confused. How are you using a new stick coil on the secondaries? As I understand the terminology, the primaries (on the top of the head) use stick coils (aka coil-on-plug), while the secondaries (on the underside of the heads) use a conventional separate coil and plug wires. Which ones are you pulling?

[TyTass]

You're correct about one thing for certain ... one of us is confused!

 

My documentation (Clymers) lists the opposite case (which I thought odd): Secondaries having the stick coils and on the top of the cylinder. Primaries underneath with their coils mounted up on the frame.

 

I don't know who's right. Twisty, can you straighten us out?

[Boffin]

Clymer is wrong.

 

Andy

[TyTass]

Well that makes more sense then. Why would the primaries be underneath? But I followed suit and used their orientation. Doh!

 

Thanks for setting me straight.

[CoarsegoldKid]

I was wondering if a 911 device would have diagnosed the bad coil.

[Ken H.]

Nope. The Motronic does not monitor the coils, so there is nothing (codes) for the GS-911 to go get.

[TyTass]

Apparently ... I can't read my Clymers correctly.

[TyTass]

OK, the technical publications QC Manager who can't seem to read his Clymers believes he's fixed his probs.

 

I replaced the right PRIMARY stick coil and rode my bike to work and back - playing a bit on the way home. Idle was now up to 1100 and it no longer cut off when cold despite the "choke" being on). However, that ranging was still present, especially when I hit the servo brakes or lights or whatever electrical. Even when warm-ed up - though I admit that again it wasn't as bad as before replacing the right primary sc.

 

When I came home, my 2nd stick coil I had previously ordered had arrived. Just replace the left primary and voila! No ranging, smooth idle, and my bike would idle well without "choke" even at 1 bar. Hasn't done that in some time.

 

Thanks for the help, all!

 

 

[realshelby]

Makes me think I should buy another stick coil for my left cylinder. Just in case it is not 100%. Seems like 40K miles and up and these things become suspect.

[Bernie]

Reading this treat makes me think that these stick coils can have a very different action when hot or cold, and at low and hi rpm.

I think with 40 K on my Hexhead, I better start looking into a payment plan for stick coils (4x), maybe one a month.

[realshelby]

I don't know the answer to this: Does the Hexhead use 4 stick coils? Oilheads use only 2, The late "twin spark" heads have the secondary plugs fired by remote coil and conventional spark plug wires.

[Justin_B]

Does anyone know the primary resistance of a new stick coil? I found .87 ohm in a thread over on r1150r.org. Seems I've read somewhere (as far as Airheads go) that it's OK to use a coil with a bit less resistance than stock but best to not go over. I find that Dyna makes a dual coil with .7 ohm primaries and I'm tempted to order one. Not wanting to beat an already dead horse but if both plugs fire at the same time (wasted spark) then I see no reason a $70 Dyna "Blue" and some fabricated plug wires could not replace these obviously problematic pieces.

[Bernie]

The hexhead uses 4 stick coils. The service tech tells me that the bottom plugs fire at idle at the same time as center plugs, but at higher rpm the timing changes and is almost useless or ineffective. I think that the lower plugs foul (not knowing a better term for what is happening) at extended high rpm use. He thinks it takes a little bit for the computer to change the mixture to idle conditions (O2 sensor slow?).

Oh well, I guess the same applies for the Hexheads as for the R1100RT, keep the rpm's above 4grand and wear earplugs.

[flat_twin]

OK, the technical publications QC Manager who can't seem to read his Clymers believes he's fixed his probs.

 

I replaced the right PRIMARY stick coil and rode my bike to work and back - playing a bit on the way home. Idle was now up to 1100 and it no longer cut off when cold despite the "choke" being on). However, that ranging was still present, especially when I hit the servo brakes or lights or whatever electrical. Even when warm-ed up - though I admit that again it wasn't as bad as before replacing the right primary sc.

 

When I came home, my 2nd stick coil I had previously ordered had arrived. Just replace the left primary and voila! No ranging, smooth idle, and my bike would idle well without "choke" even at 1 bar. Hasn't done that in some time.

 

Thanks for the help, all!

 

 

Your avitar is WAY too distracting. I couldn't keep my mind on the thread, instead I kept watching the damn ping pong game!