85 R80RT...Motor quit

[franko]

I have a 85 R80RT with 49,000 miles on her.
The wife and I road out for dinner, about a half hour ride.
When we finished, after about 45 minutes, I started the bike up, she ran for a minute then died.
After checking switches and the fuel tank, I pulled a plug, rested it on the cylinder and cranked the bike again.
No spark.
I have her back at the house and started trying to find the fault.
Using the Clymer manual, on page 392, I have gotten to step 4.
When I do this test, My reading comes out to a negative 1.49 on the meter, set at 20 VDC.
I made up a wire with a ring connector for the #1 terminal on the coil and a alligator clip to attach to the negative battery terminal.
The book says to take the reading from the #15 terminal on the coil to the positive terminal on the battery.
Does this seem right?
I have 12.04 volts at the #15 and 12.07 on the battery. It is probably down from the cranking and now has a trickle charger hooked up.
Am I doing something wrong in this test? If so, could anyone point me in the right direction?
Thanks, Frank

 

[franko]

So. Continuing on.
I went to step 5. With this I did have the 12 volts.
When I did step 6, the book was looking for at least 5 volts. I had 11.9. This seemed high, compared to what was being looked for.
Skipping step 7 because the voltage was more than the minimum asked for, I started with step 8.
With this step, I wish I had waited until everything was taken apart and ready to test before I had reconnected the ground. As I used a small screwdriver to release the connector for the trigger unit, I had a small spark from grounding out the frame of the diode board and the engine case, but this will have to wait for another time to check out.
I bared the end of a wire and used shrinkwrap to make a small connector to go to the center pin. With the ignition on, I grounded this wire several times and a spark did not occur.
I am thinking it is the trigger unit from what I have read.
All guidance is appreciated, as I don't want to just replace parts and have her sit when it turns out I am wrong. Thank you for any help. Frank

 

[bmdehut]

Look at your coil for cracks. If it has any it's junk. Also have you ever renewed the heat sink paste under your ignition control unit? Just a couple things you should know. Also, if your not getting help here go to Adventure Rider - Bikes - Old's cool - then Airheads.

 

[guenner]

The center pin on the ignition sensor is the signal for "spark". It is usually pulled high to ~9V and close to ground for a "spark". That's why you ground that pin to check the ignition module by bypassing the ignition sensor!

So I assume the ignition sensor is OK but either the ignition module, or the coils are the problem.

Check the resistance of the primary and secondary coils (Ohms from the Clymer manual).

/Guenther

 

[franko]

Bmdehut and Guenther: Thanks for the replies.
I pulled the coil to get easy access to it.
The primary side shows 0 resistance, the secondary side shows 8.5 using the Clymer instructions.
The primary side must have a short in it.
With this information, the coil is shot.?
Just a new coil is where I'm at now.
I'm open to suggestions for a coil or further updates as long as I'm this far into her.
Thanks again for the help.
Frank

 

[20774]

Whenever I've measured the resistances, I put one meter lead into the left spark plug cap and the other lead in the right plug cap. The reading should be 20K-24K ohms. Generally, the measurements add up by 5K for each of the spark plug caps and another 10K for the coils. Can you measure that way?

 

[bmdehut]

Check out airhead parts, the dark secret on Adv site. There may be a suggestion for a cheaper coil. I ran a single two post harley coil and a /6 for a lot of years

 

[guenner]

Did you check your Ohm meter before by putting its leads together and you see 0 Ohms?

If truly zero then there is a chance that the ignition module got shot as well.

Btw. is this the old grey colored coil?

/Guenther

 

[happy wanderer]

Bmdehut and Guenther: Thanks for the replies.
I pulled the coil to get easy access to it.
The primary side shows 0 resistance, the secondary side shows 8.5 using the Clymer instructions.
The primary side must have a short in it.
With this information, the coil is shot.?
Just a new coil is where I'm at now.
I'm open to suggestions for a coil or further updates as long as I'm this far into her.
Thanks again for the help.
Frank

Does your coil look like this one?


If it does you have the famous "Crack O' Matic" dual tower coil and this one shows the classic symptoms found. Notice the crack and black carbon deposits from the shorting going on at high voltage. These ALL fail in time as BMW used a cheaper supplier who used cheaper plastic to encase the coil with bad results. They replaced it with part number 12 13 1 244 426 at some point.

To get thoroughly educated on this problem go here: http://bmwmotorcycletech.info/ignitionsingleplug.htm and use the find feature to look up "crack" and read section D. And more if you like. It's Snowbum's site and there is plenty more to read there! His knowledge is enclyopedic (is that a word?) and his site is extremely useful for those who want very in depth info.

 

[franko]

Well back at it.
Happy wanderer: all the numbers are the same except the 141, mine is 544. I don't see any cracks, but I didn't clean it well.
Guenther: When I went to use my multimeter, the battery had leaked. I was able to clean up the mess with electronic cleaner. With the new battery in it, I zeroed it out.
The coil looks black to me. The area under the plug wire boots is definitely black.
With the high reading on the ignition module, I starting to think the same thing.
Bmdehut: I'm on the ADVRIDER site as franko58. I've gleaned a lot of information and scored a few parts from there.
20774: I checked the coil according to the clymer book. the table has a primary reading for this coil of 1.15 to 1.32 on Rx1. I have 0. I will get a reading with the plug wires in the coil later this weekend. The wires are BMW and about 6 years old.
With the readings and miles on her (and the riding I intend to do), I decided to order the control module, bean can up date and a blue coil from motorade electrik.
Hopefully, the small arc didn't mess up the diode board.
So, it's going to take a week or two for the parts to get here (they're back ordered), the push rod tube seals need to be replaced and splines lubed. I guess she wanted the attention. A second Norton (not mine) needing work has moved into the garage with her. Jealousy is raising its' head.
Thanks for the advice and I will save the parts for a tech day investigation.
If it wouldn't hurt anything, I could replace just the coil first to see if she fires up. I will replace the rest just to not have to wonder for another 50,000 miles.
Frank

 

[happy wanderer]

Well back at it.
Happy wanderer: all the numbers are the same except the 141, mine is 544. I don't see any cracks, but I didn't clean it well.
Guenther: When I went to use my multimeter, the battery had leaked. I was able to clean up the mess with electronic cleaner. With the new battery in it, I zeroed it out.
The coil looks black to me. The area under the plug wire boots is definitely black.
With the high reading on the ignition module, I starting to think the same thing.
Bmdehut: I'm on the ADVRIDER site as franko58. I've gleaned a lot of information and scored a few parts from there.
20774: I checked the coil according to the clymer book. the table has a primary reading for this coil of 1.15 to 1.32 on Rx1. I have 0. I will get a reading with the plug wires in the coil later this weekend. The wires are BMW and about 6 years old.
With the readings and miles on her (and the riding I intend to do), I decided to order the control module, bean can up date and a blue coil from motorade electrik.
Hopefully, the small arc didn't mess up the diode board.
So, it's going to take a week or two for the parts to get here (they're back ordered), the push rod tube seals need to be replaced and splines lubed. I guess she wanted the attention. A second Norton (not mine) needing work has moved into the garage with her. Jealousy is raising its' head.
Thanks for the advice and I will save the parts for a tech day investigation.
If it wouldn't hurt anything, I could replace just the coil first to see if she fires up. I will replace the rest just to not have to wonder for another 50,000 miles.
Frank

The 141 is just a run or production number so you have the Crack O Matic and really it's amazing it lasted this long. Same deal for me. I have a low kms R80G/S and mine burned out last year at around 60,000 kms or 40K miles.

 

[franko]

20774: Hi kurt, The plug wires tested at 5,06 and 4,98. When I plugged them back into the coil, The total reading is 22,50. That is in the ballpark, so I'm going with the primary circuit shorting out. Thank you for the advise. When the parts arrive, I will try just the new coil first. Frank

 

[franko]

I received the parts from Motorrad Electrik this afternoon.
As I had her disassembled it only took a couple hours of reading and assembling to get her back together.
With setting the new bean can according to instructions the timing didn't need any adjustment.
I had said that I would just install the new coil to see if it would run, but overcast skies and approaching night fall....... oh hell I just wanted to get her running again.
I have saved the parts for a tech day in Wisconsin or Northern Illinois.
She starts easier now and idle comes in quick as with the old system it took a bit to idle down.
The hardest part of the install was getting the bolts back into the rear hinge of the seat.
As of tonight I happy with my purchase.
I had also stated about a small spark off of the diode board as I was trying to get the clip off of the connection of the bean can. I think I got away with this one, as I didn't see a charging issue on the test ride.
So here is to tomorrows ride with the Mrs.
Thanks to all who offered insight.
Frank Coleman

 

[happy wanderer]

I received the parts from Motorrad Electrik this afternoon.
As I had her disassembled it only took a couple hours of reading and assembling to get her back together.
With setting the new bean can according to instructions the timing didn't need any adjustment.
I had said that I would just install the new coil to see if it would run, but overcast skies and approaching night fall....... oh hell I just wanted to get her running again.
I have saved the parts for a tech day in Wisconsin or Northern Illinois.
She starts easier now and idle comes in quick as with the old system it took a bit to idle down.
The hardest part of the install was getting the bolts back into the rear hinge of the seat.
As of tonight I happy with my purchase.
I had also stated about a small spark off of the diode board as I was trying to get the clip off of the connection of the bean can. I think I got away with this one, as I didn't see a charging issue on the test ride.
So here is to tomorrows ride with the Mrs.
Thanks to all who offered insight.
Frank Coleman

Yep, that's why the experts say ALWAYS disconnect the battery whenever you are working in there and especially taking the cover on and off. Sparks will fly 9 times out of ten. DAMHIK...
Glad you got it fixed and congrats. Your crack o' matic lasted longer than mine!