Boxer smooth as silk (as much as a lumpy twin can be)

[duke]

I finally got rid of all the problems plaguing my bike (twin spark).

Earlier today I changed one of the stick coils - and pronto.

Shame on BMW for designing the coils like this and even greater shame to ask for this much money for the spare part they are aware fails so often.

Now - it begs a question. Has anybody heard of the following:

Redesigning the ignition on the twin sparks so that instead of the coils for the primary plugs being inside the cylinder heads they are moved somewhere inside the body and correspondingly replace the 12 V leads with HT leads.

Or am I talking out of my lower backside?

Please feel free to tell me to stop thinking ...

[The Velvet Monkey]

I'm looking forward to hearing the responses as I'm on my way to the dealership to buy my second coil in six months--and they are expensive.

[riceburner]

It's an interesting idea.

The reason they're used is that "everything" uses them now - BMW use them on the cars, and I noticed that the 1200 twins have them on all 4 plugs.

It's not impossible that from a manufacturers point of view, they're cheaper to use and install.

[CycleRob]

Almost all the Japanese bike have had them for about the last 8--10 years. The failure rate is low compared to BMW's. So low that I have not seen one fail up to the point of my retirement from wrenching on them in mid August 2005. I have a good hunch why the BMW coils are failing. HEAT!!. Too much heat!! The majority of those Jap bikes are water cooled so the temp rarely goes over 220F (104.4C). On the air/oil cooled BMW's it can frequently go over 250F (121.1C). Combine the extra heat with lowest bidder German electronics and you get what we have: Failures with denials and regular replacements needed.

About relocating the coils . . . . Just take them away from the extreme heat, out of the sparkplug hole to somewhere nearby and run a length of secondary plug wire from the coil to the sparkplug. Creativity required to make it work and look stock. I bet the failures will stop . . . . cold.

.

[boxermania]

CycleRob +2

Heat is the killer of electronic components and the boxers being air cooled run hotter than water cooled bikes.

The shame of it all is that BMW boxers should not fall prey to all these maladies, as in my book that is the result of shortsighted engineering and poor product stewardship.

At least that's my opinion.......

[Beemeridian]

11

[duke]

No doubt about the heat ... that is why I want to move the coils if possible.

I took it for a spin today ... what a joy!
The firing sounds so even.
Throttle response is so nice and the bike goes like turbo train up the hill on the A102.

Even managed to embarrass some d***head with BMW M3 from the traffic lights ... he nearly stalled in frustration
But - he should have known better - the warning signs (the BMW roundells) were clearly visible on the oil-cooler covers

[CycleRob]

Beemeridian,
I'm sure you did it correctly, but the wire pull to test procedure needs more details.
The primary coil on the single and dual sparks fires both sparkplugs at the same time, ~every TDC of both pistons. The wasted spark occurs on the end of the exhaust stroke of the next cylinder. The spark travels thru one sparkplug to ground then from ground to the center electrode of the other sparkplug then back to the coil. Yes, one sparkplug fires backwards. If you pull off the secondary plugwire and do NOT ground it good with another sparkplug inserted then the other plug will not fire.

Also, you must never open fire any sparkplug wire - - (sparkplug end ungrounded). Doing so forces the 40,000 Volt energy pulse to jump any internal insulation weaknesses or it's own terminal air gap. Once the path is burned in, the coil is most likely damaged.

.

[Beemeridian]

11

[gel9001]

maybe we should all replace our coils I have 34k on my 2004 twin spark, looks like chicago bmw wants about 76. for them

[CycleRob]

There's no need to replace your bike's primary ignition coil. It's meant to last the life of the bike, just like the coils in your car. Problems can arise if it's sprayed with roadside conductive liquids or water splashed on it's dirty exterior. Winter riders can encounter salty water unknowingly splashed on the coil from roadside puddles or vehicles ahead of them. The slightest break or leak in the coils functional insulation will have that bike chuffing to a stop with no spark.

If you want to do something to prevent any coil failures . . . . clean it. The next time your fueltank is off, use an old toothbrush, a mild soapy water solution and some gentle scrubs to clean off it's exterior. Pay particular attention to the hard plastic areas around the secondary (sparkplug) wires. Then rinse it off well and let it air dry or pat it dry. I would avoid a compressed air blast to dry it as it may push water into where it doesn't belong. No need to remove any wires.

Also, follow the path the secondary wires take, checking for chafing against sharp corners.

.

[Croc]

Thanks for the info on cleaning the coil, Rob. I will be replacing my fuel filter soon so the opportunity is there! I was at the local dealer yesterday and got a quote for new primary coils - £80 each! Ouch.
Dealer also said that he has had R's in before where the owners have not changed the fuel filter and the end has blown off the filter! Seems that BMW designed them this way for safety as they are placed after the fuel pump. Does this sound right??

Croc

[duke]

... I was at the local dealer yesterday and got a quote for new primary coils - £80 each! Ouch. ...

WHAT???

Do you mean £80 for the coils for the primary spark plug on a dual spark machine?
That is a highway robbery!!!

Try MotorWorks for better pricing.
And their customer service is second to none.

Ignition coil (R850/R1100GS/R/RS/RT and all R1150 single spark models) - ELA41978 - £45 (inc VAT)
Ignition stick coil (R1100S/ R1150 twin spark) - ELA71896 - £53.84 (inc VAT)

[riceburner]

Beemeridian,
I'm sure you did it correctly, but the wire pull to test procedure needs more details.
The primary coil on the single and dual sparks fires both sparkplugs at the same time, ~every TDC of both pistons. The wasted spark occurs on the end of the exhaust stroke of the next cylinder. The spark travels thru one sparkplug to ground then from ground to the center electrode of the other sparkplug then back to the coil. Yes, one sparkplug fires backwards. If you pull off the secondary plugwire and do NOT ground it good with another sparkplug inserted then the other plug will not fire.

Also, you must never open fire any sparkplug wire - - (sparkplug end ungrounded). Doing so forces the 40,000 Volt energy pulse to jump any internal insulation weaknesses or it's own terminal air gap. Once the path is burned in, the coil is most likely damaged.

.

WTF???

where on earth did you get that information??

Firstly - the plugs will only fire on the Firing stroke, to fire the plug on the exhaust stroke would ignite unburnt fuel in the exhaust with the exhaust valve AND inlet valve open (If I remember correctly this is how most 4-stroke engines work - the inlet and exhaust opening overlap) : CATASTROPHIC backfire. you'd quite possibly blow the throttle bodies off. (worst case scenario)

Secondly - you've not got a "backwards" plug in the bike - the Spark is generated by creating a huge electrical potential difference (voltage) across the two terminals - one at earth, one connected to the coil. Each plug has that PD (potential difference) generated seperately. If not - for starters you'd destroy the secondary coils with reverse polarity current, and secondly - if the primary coil dies, then, in the system you describe, the secondary plug won't fire either - which is NOT the case - it's very possible to run the bike with the primary plugs inactive (due to failed coils). If you tried to run the bike with BOTH right side plugs not firing the bike simply wouldn't run.

I agree that it's possible to burn out a coil by "blank" firing it - but you'd have to run it for sometime to manage that I would have thought.

[riceburner]

There's no need to replace your bike's primary ignition coil. It's meant to last the life of the bike, just like the coils in your car. Problems can arise if it's sprayed with roadside conductive liquids or water splashed on it's dirty exterior. Winter riders can encounter salty water unknowingly splashed on the coil from roadside puddles or vehicles ahead of them. The slightest break or leak in the coils functional insulation will have that bike chuffing to a stop with no spark.

If you want to do something to prevent any coil failures . . . . clean it. The next time your fueltank is off, use an old toothbrush, a mild soapy water solution and some gentle scrubs to clean off it's exterior. Pay particular attention to the hard plastic areas around the secondary (sparkplug) wires. Then rinse it off well and let it air dry or pat it dry. I would avoid a compressed air blast to dry it as it may push water into where it doesn't belong. No need to remove any wires.

Also, follow the path the secondary wires take, checking for chafing against sharp corners.

.

Rob - you ARE aware that the "primary" coils are encased within the plug cap for the main plugs?? The wire that goes to the is the firing signal, but it's a low-tension cable - not the usual HT lead (as on the secondary coil leads).

The coil you describe is the "secondary" coil for the under-slung plugs that BMW added to improve combustion and reduse the dreaded "surging".

[slowpoke 04]

QUOTE "Firstly - the plugs will only fire on the Firing stroke, to fire the plug on the exhaust stroke would ignite unburnt fuel in the exhaust with the exhaust valve AND inlet valve open (If I remember correctly this is how most 4-stroke engines work - the inlet and exhaust opening overlap) : CATASTROPHIC backfire. you'd quite possibly blow the throttle bodies off. (worst case scenario)"

I can not intelligently discuss BMW wiring or ignitions, but, I can tell you on my 70's Triumph 650s and Norton 750 using Boyer Electronic Ignitions, both plugs fire at the same time. One is on compression or BTDC would be more correct and the other is on end of the exhaust stroke. I don't see any explosion of parts and I can't see why it would not work on any two cylinder four stroke engine that way. I know it is firing that way because I can time the engine using either plug and the same timing mark.

[bluelight]

I got stuck in traffic on my little towns main street, and I got pissed off. Well then the R
started getting pissed off and the engine started clicking, like the oil was low, it wasnt.
I think it was getting hot, can that cause the clicking, or coils? Well I took a detour around
the New Delhi traffic jam, and wound up on I bit of a hill at a red light, (going up). Well next I did something stupid. The light turned green and I stalled it. Stared it up and took off in third.

Well I went down to the beach, LI sound and chilled out. On start up the clicking was gone
and I had cleared out my head. Was the clicking in my head?

[CycleRob]

Yes, I did get the primary & secondary terminology mixed up as I was addressing the "pull the wire" testing procedure to Beemeridian. Primary is the computer coils. Secondary is the bottom sparkplugs powered with the twin coil like on the single spark models.

Both plugs on my single spark model DO fire every turn near TDC. So do the fuel injectors !! One of the 2 sparkplugs DOES fire backwards. That's how those coils work. It's a very cheap, minimalist ignition system common to many recent distributorless 4 cylinder cars too. The majority of older 4 cylinder motorcycles also have a pair of the same type of "fire every turn" twin plugwire coils. The wasted spark on the "other" cylinder fires harmlessly at the end of the exhaust stroke and just as the intake valve barely starts to open. It's not the best ignition system power wise, but it sure is the cheapest.

.

[Beemeridian]

11

[duke]

... I noticed the coil has a new design. I pulled one from a nearby R1200R and they are identical.

Does it have silverish-grey top?

I hope they are new model or new sub-contractor ... I would hate to have to swap them ever so soon again.