Running on one cyclinder

[RTP'er]

I ran into the local burrito place and when I came out after 15 or so minutes the bike ran real rough and without power. I restarted it several times with no difference.

I made it home and have since confirmed it is only running on the right side. When I pull the left spark plug wire off it runs the same, pull the right one off and it won't start.

I took the valve cover off (did recent tune up with valves etc) to make sure a valve hadn't backed loose which it didn't. Took the new spark plug out and it looks clean and perfect.

 

So, is there a coil for each side for the 2001 1100RTP? Can the hall sensor only affect one side? Ideas?

[T__]

RTP, same coil is used for both sides so that is probably OK.. In fact both sides spark together so Hall sensor is working & so is the trigger circuit in the PCM..

 

Do you have compression on that side? If so make sure the injector is plugged in.. If still no problem found try swapping injectors side to side..

 

Might try swapping spark plugs side to side also..

 

Something not working there..

 

Twisty

 

 

 

[Unhofliche_Gesundheit]

what about the old standby of checking for spark?

pull out the plug, keep it connected to the lead, run the starter with the plug grounded against a fin etc .. should see fat blue spark.

 

obviously insulate yourself during this operation.

 

i'm not sure if this dangerous and not recommended on this bike - can anyone advise?

 

if you have spark then suspect the other 2 options: fuel or compression.

[T__]

what about the old standby of checking for spark?

pull out the plug, keep it connected to the lead, run the starter with the plug grounded against a fin etc .. should see fat blue spark.

 

obviously insulate yourself during this operation.

 

i'm not sure if this dangerous and not recommended on this bike - can anyone advise?

 

if you have spark then suspect the other 2 options: fuel or compression.

 

 

Cameron, if you have spark on one side pretty difficult to not have spark available on the other.. The single spark oilheads use what is called a “lost” or wasted spark system.. That involves only one ignition coil that sparks both sides together & at the same time.. Both plugs are used in series so basically one side spark plug & wire is the return path to the coil for the other side.. They will operate with one plug wire off or open but not a very good spark as it then relies on internal coil arching to complete the spark secondary circuit & that is sure to fail the coil in short order..

 

Never a bad idea to check fro spark on both sides but on the oilhead single spark if you have spark on one side more than likely you also have it on the other..

 

Twisty

 

[T__]

RTP, I missed something in my post above..

 

It’s possible you have a rock caught in the non operational side throttle cable cam at the TBI.. Or other cable/TBI problem holding the throttle slightly open.. That can cause a dead cylinder on that side..

 

If you did any cable adjustment during service you probably should check to MAKE DARN SURE both side TBI’s are opening & closing at the exact same time (make sure they both hit the idle stops at the same time)..

 

Twisty

 

[RTP'er]

Well, that is what I was just doing outside.

I took the left spark plug out and ran the starter. Compression is fine. Plugged the spark plug in and grounded it. NO SPARK!

Here comes the weird part. I plugged that spark plug in on the right side, and it sparks fine with the same method.

So, I have spark on the right and not on the left. Could the wire just be loose at the coil? I can't quite reach under the tank to feel the connection....

[T__]

Well, that is what I was just doing outside.

I took the left spark plug out and ran the starter. Compression is fine. Plugged the spark plug in and grounded it. NO SPARK!

Here comes the weird part. I plugged that spark plug in on the right side, and it sparks fine with the same method.

So, I have spark on the right and not on the left. Could the wire just be loose at the coil? I can't quite reach under the tank to feel the connection....

 

 

RTP, sure the plug wire could be off the coil or the wire itself pulled out of it’s terminal at the coil or even the spark plug end..

 

If it is don’t run it long that way as it is arcing internally inside the coil to produce the R/H spark..

 

You didn’t have the other side disconnected from it’s spark plug when testing the dead side did you? If so reconnect that & test for spark again..

 

Twisty

 

 

 

[RTP'er]

I had the other side disconnected when I did both tests. So when it sparked on the right the left was disconnected, and when it didn't spark on the left the right was disconnected. So since I got a spark on the right side I am assuming it works that way.

 

So I have to take the tank off to reach the coil? This is all new to me.

[T__]

I had the other side disconnected when I did both tests. So when it sparked on the right the left was disconnected, and when it didn't spark on the left the right was disconnected. So since I got a spark on the right side I am assuming it works that way.

 

So I have to take the tank off to reach the coil? This is all new to me.

 

 

RTP, before pulling the tank try your spark test again with the other side connected or at least grounded.. One side of the system sparks positive ground & the other side sparks negative ground so might make a difference with an open plug wire..

 

 

Twisty

 

[RTP'er]

Losing light fast, but I was just outside doing that. I wanted to rule out your theory. The right side was connected and still no spark on the left. In fact, the bike started on the right cylinder with no spark on the left.

 

At this point I am thinking faulty spark plug wires. I am going to have to pull the tank tomorrow.

[Mike T]

You should be able to slid the tank back on the bike without disconnecting the fuel lines and gain access to the coil.

[RTP'er]

Well I did that. The wire was still attached to the coil. In fact it has a nut holding it on. So, unless it is an internal problem in the spark plug wire I would suspect the coil. What I think is weird is that it is still sparking on the right side. Has anyone ever had the coil go out on just one side?

I guess I am going to find my continuity meter to test this wire but I have a feeling it is fine.

This whole thing seems real weird to me.

[T__]

Well I did that. The wire was still attached to the coil. In fact it has a nut holding it on. So, unless it is an internal problem in the spark plug wire I would suspect the coil. What I think is weird is that it is still sparking on the right side. Has anyone ever had the coil go out on just one side?

I guess I am going to find my continuity meter to test this wire but I have a feeling it is fine.

This whole thing seems real weird to me.

 

 

RTP, while anything is possible the coil on your single spark BMW uses the same internal winding to spark both sides.. The entire secondary side is a continuous circuit through the coil secondary winding & both spark plugs..

 

In a conventional ignition coil one end of the secondary winding is tied back into the primary to see a ground (or low) on one end of the secondary winding & the other end goes to a single spark plug then into ground for the return path & complete circuit..

On the BMW wasted spark coil neither end of the secondary coil is tied into the primary but uses the entire secondary continuity to complete the return & complete the circuit..

 

I suppose it would be possible for the coil secondary coil to short out internally & seek a short to ground inside the coil itself.. But that would leave a very low output on the operational side & a very short coil life..

 

 

My guess is if you only have spark on one side that you have an open in the plug wire on the failed side or a short to ground in the wire on the failed side..

 

There is some built in resistance in the BMW plug wires to prevent RFI from interfering with radio reception & prevent back talk to the PCM so even a good wire will show some resistance..

 

Probably first try swapping plug wires side to side to see if the failure follows the wire move..

 

Have you tried the good side spark plug in the bad side plug wire to see if the good side spark plug will spark on the failed side? Each side sparks at different polarity so it is conceivable that a bad plug could sort of work if the spark polarity was changed (at least open air no load spark check)..

 

 

 

Twisty

 

[Dave in Doodah]

I had this happen on my old airhead... buy new plug wires and you should be back in business...

[RTP'er]

Well, I guess I got it figured out. I had a little time this morning and switched the spark plug wires. Now I don't have spark on the right side and the bike is running on the left cylinder only. So, the wire went bad.

 

I called the dealer and they would have to order the wires at a whopping $110 each because it is an RTP. They said I could only change to standard wires if I also changed the coil.

 

This is a bit tough. Does anyone know any places I could find these wires cheaper? I saw standard sets for $59 online, $220 a set seems a bit steep.

Thanks

[Tony_K]

One call does it all!

 

973-775-3495 Beemerboneyard Mike F

 

Don't even waste your time looking anywhere else.

 

Just call Mike. He will get you set up and your items shipped TODAY!

[Marty Hill]

If that doesn't work I sent you a pm with another place.

[RTP'er]

I talked to Beemberboneyard and he can't help me with wires for the RTP. I also checked on Marty's suggestion. The price is better there than my local dealer but I am still kinda shocked at this.

 

Anyone here have any laying around taken off an RTP? All I need is one.

Thanks

[outpost22]

You might try posting it HERE too.

[Polo]

Check this out. Talk to these guys, maybe they can be of help.

 

http://beemerboneyard.com/coplwi.html

 

Good luck.

[Dave in Doodah]

I would make the effort to find a new one (or preferably two) rather than finding a used one. Plug wires have a finite life and will need to get replaced every so often, from my experience...

[T__]

I talked to Beemberboneyard and he can't help me with wires for the RTP. I also checked on Marty's suggestion. The price is better there than my local dealer but I am still kinda shocked at this.

 

Anyone here have any laying around taken off an RTP? All I need is one.

Thanks

 

RTP, there are some offerings on E-Bay.. Not sure if the 1100 shown will interchange (have no reason to believe it won't though).. There is also an 1150 twin spark system that might be the same as far as the single coil part goes.. Worth researching anyways..

 

 

 

 

http://cgi.ebay.com/ebaymotors/BMW-R1100RTP-1100-RT-RTP-Coil-With-Plug-Leads_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQitemZ190256968524QQptZMotorcyclesQ5fPartsQ5fAccessories

 

Twisty

 

 

 

[RTP'er]

Thanks, I bought the used set from your Ebay link. I know I should buy new wires but this way for $22 I am back on the road until I can. And I will have a spare wire and coil too.

 

Weird how Ebay works. I had run a couple of searches earlier and didn't come up with those.

[T__]

RTP, yes E-Bay is a funny search engine.. I found nothing under my first BMW searches then used rtp + coil + wires in ALL CATAGORIES & came up with the ones I posted above plus the 02 twin spark plus a few non related..

 

I’m sure not an E-Bay expert (my wife might dispute that though) but found it all depends on how it is listed by the seller.. If the seller mis spells it then it might not show up on a common search or if the seller doesn’t use the BMW before the part it might not show in a BMW ??? search..

 

I have found some real good deals on E-Bay where the seller mis-spelled or mis-listed the item so few could find it to bid on it..

 

Twisty

 

 

 

[Woodie]

Glad to see you found it. Until you mentioned it, I had forgotten that the RTP uses a different coil/cables than the regular RT.

 

FYI, it provides better/more RF suppression than the civilian ones.

 

[Mike T]

You might try calling these guys. They made a set for my R1100RS for under $100. They've worked fine for over 3 years.

 

http://www.nology.com/

[Boz]

Ran a set of Nology plug wires on a race car years ago. Good stuff.

[T__]

You might try calling these guys. They made a set for my R1100RS for under $100. They've worked fine for over 3 years.

 

http://www.nology.com/

 

Mike, big difference between your RS standard type push in unshielded plug wires & the special nut attached & fully shielded RTP plug wires..

 

I seriously doubt they have the special metric attaching & shielding hardware & even if they did those would not be $100.00 wires for sure..

 

Remember the RTP uses a very unique & special ignition coil & spark plug wire set with full RFI shielding..

 

 

Twisty

 

[Mike T]

You might try calling these guys. They made a set for my R1100RS for under $100. They've worked fine for over 3 years.

 

http://www.nology.com/

 

Mike, big difference between your RS standard type push in unshielded plug wires & the special nut attached & fully shielded RTP plug wires..

 

I seriously doubt they have the special metric attaching & shielding hardware & even if they did those would not be $100.00 wires for sure..

 

Remember the RTP uses a very unique & special ignition coil & spark plug wire set with full RFI shielding..

 

 

Twisty

 

Twisty, would it be possible to change the coil so that non-RTP spark plug wires would work? Here's a good deal on a coil and wire set for the price of one RTP spark plug wire:

 

http://www.euromotoelectrics.com/ProductDetails.asp?ProductCode=BMW-WS1100TK%2B

 

 

[Tony_K]

Just to give you a quick answer (even if it was not asked for me to answer)

 

Of course you can change the coil and wires. The RTP's are shielded which in effect is ONLY useful for reducing radio frequency noise/ interference.

 

It's just your standard wires and coil dressed up in armor, nothing more except for cost.

 

 

[T__]

You might try calling these guys. They made a set for my R1100RS for under $100. They've worked fine for over 3 years.

 

http://www.nology.com/

 

Mike, big difference between your RS standard type push in unshielded plug wires & the special nut attached & fully shielded RTP plug wires..

 

I seriously doubt they have the special metric attaching & shielding hardware & even if they did those would not be $100.00 wires for sure..

 

Remember the RTP uses a very unique & special ignition coil & spark plug wire set with full RFI shielding..

 

 

Twisty

 

Twisty, would it be possible to change the coil so that non-RTP spark plug wires would work? Here's a good deal on a coil and wire set for the price of one RTP spark plug wire:

 

http://www.euromotoelectrics.com/ProductDetails.asp?ProductCode=BMW-WS1100TK%2B

 

 

 

Mike, sure you can (at least I can’t think of a reason you can’t) … Should be a direct spark plug wire & coil bolt on swap.. Only problem might be the RTP coil has shielded primary side also so might not be a direct plug in on that side (not sure the harness connection is the same or if you will need to swap the connector on the harness to match the standard coil.. In any case not a show stopper but might take some rework in that area.. I haven’t ever compared the coils side by side so I really can’t say for sure the primary side won’t be a direct fit..

 

 

Twisty

 

[RTP'er]

For now I got a used coil with spark plug wires attached for $12.95 on Ebay. I installed one of the wires today and the bike runs fine again. I would have rather put on new wires but the price was right to get me back on the road.

Weird how a wire could completely fail like that.

[SWB]

For future reference (which I'd seen your posting earlier), I replaced my coil and wires with products from Nology too, the first month had my RT-P. The coil disintegrated as I attempted to remove the retaining nuts (I swear it looked like BMW service used loctite on those nuts!). No way was I going to be "trapped" into buying a $300 coil and two $110 wires. I had to make a bracket to mount the coil, but it's worked perfectly (and felt stronger) ever since. Nology is local to me, so I drove over. I buggered up one of the wires trying to put it together, and I went back for help. The manager went back and made me a new wire on the spot, helped me with the coil spec comparison, tested my old one and their new one, did everything except mount the thing on my bike. Great people.

 

You have a good solution now, but I don't trust old rubber, so I'd do the same thing again today had I to do it over again. I can't recall what I paid, but I think it was about $120 to $140 for the coil and wires (coil was $69 for sure).

 

- Scott

[karlheinz]

For now I got a used coil with spark plug wires attached for $12.95 on Ebay. I installed one of the wires today and the bike runs fine again. I would have rather put on new wires but the price was right to get me back on the road.

Weird how a wire could completely fail like that.

Just read all about your problems here.I have had a similar problem with my 98 rt/p.It was running but missing on one side every so often.It drove me nuts trying to figure this thing out.Ohms resistance checked out everywhere coil,wire right to spec.Replaced coil and wires from a regular rt and things are fine now.But it bothered me not knowing what the problem was so I really started scrutinizing the old parts.What I found was the little spring that sits in the end of the screw on connector(wire portion) never fit properly into the coil receptical thus creating a gap.

[andrewwinghale]

I had a simular situation, long story short,

Having gotten my RT back from the Dealer after a fuel pump replacement it ran at proper Idle but on one cylinder.

I plugged the left "fuel injector" connector in properly and it then ran on both cylinder's and at twice idle speed.

RT ran fine before the fuel pump replacement/first new pump they put in was bad and they messed further "no Code's".

Next morning I got the Murcury stick's out, all well since.

Will not go to that Dealer again.

A fuel injector problem could cause a same symtem.