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Discussion Starter · #1 ·
I am in need of some help/advice. I own a 95 M900, last time I went out for a ride my bike all of sudden lost power and would not accelerate at all, it would still idle but it sounded like only one cylinder was firing(not sure if this was the case as I couldn't tell with the heat of the engine or the lack of tools I had on me). Every time I would give it throttle it would sputter backfire and die before it would even get the clutch engaged. Each time I was able to start it, it would idle but would sputter, backfire and then die when I gave it any throttle. My first reaction was it was most likely a fuel problem as I just filled up about 20 miles earlier. After getting it hauled home I tried to start the bike again and would not start at all(engine turned over just fine). I had power everywhere else and all the fuses were fine. So first things first I started with the spark plugs, and found out I had no spark to both of the cylinders. I decided that since I was going to buy dyna coils in the future I would just order them and get a few things out of the way as far as the problem goes. After I replaced the ignition coils, spark plug wires and spark plugs it still had no spark. I took out my volt meter and measure the resistance in both the old and new coils. The secondary and primary all measure within spec in both coils new and old. I then measured the resistence to the pick up coils both the left and right and measured out within spec too. I even took the left side engine case off and measured the pick up coil gaps, and still no spark. I then measured the voltage into the ignition control modules to make sure I was getting 12volts and it checked out ok. The only thing I haven't checked is igniton control modules. It doesn't seem like both could go out at the same time and I don't really want to pay $400 for even one to see if that is the problem. Does anyone know of a way to check them? Also could it be the regular/rectifier? Any ideas?
 

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While I agree that it would be unusual for both boxes to fail simultaneously, it does sound like that is the case. Before you replace any, check all the grounds. There has to be a reason they failed together.
 

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Discussion Starter · #3 ·
This is probably is a stupid question but what grounds should I check? If I am getting power at the ignition modules it shouldn't matter?
 

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Speed7626 said:
This is probably is a stupid question but what grounds should I check? If I am getting power at the ignition modules it shouldn't matter?
As far as powering them no it shouldn't. The modules are fragile. I have no hard fast proof but I believe I lost a couple to a questionable ground on a track bike. There has to be a reason both went bad at the same time, if that is actually the problem.

I would check all the harness grounds, and the engine to frame ground on the R/H side.
 

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I tried to type up directions on testing the modules but it is too difficult for me to do it in an understandable format. I will see if I can scan you the info later. If I can't do that I will snail mail a copy to you if you PM me an address. Actually, I'm going to give it a try. Here goes:

Your module:
two pin terminal three pin terminal
P- P+ G VB 1G 1


You will need an analogue voltmeter to do the test



VB 1G 1 G P+ P- positive lead

negative lead VB O O O O

1G 1 X X X X

G X O O O

P+ X O O O

P- X O O O


Where there is a O the meter oscillates
Where there is an X it does not.

This test will show failure, but not degradation.

Terminal G on the module is ground. Check that what it is grounded to also has a good ground as well as the engine to frame.
 

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Discussion Starter · #6 ·
Thanks Howie,

Only two questions I assume I am checking the resistance (R x 1k) and O is where there is a resistance value and X is where there is an open circuit?

Thanks
 

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Opps, I wrote voltmeter. I meant ohmmeter. Use the 1 ohm setting. The meter should read infinity where there is an X and swing towards 0 where there is an O.
 

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Discussion Starter · #8 ·
Thanks for your help this is what I got when I checked both modules

VB 1G1 G P+ P-
VB X X X X
1G1 0 0 0 0
G 0 X 0 0
P+ 0 X 0 0
P- 0 X 0 0

I also got the exact ohm readings for each measurement on both modules. According to my readings if I would of switched the negative lead where I was supposed to use the positive lead they would of came out exactly as they should of by your diagram. So I am assuming that the units are bad except the readings were backwards from what they should be. Hopefully what I said makes sense.
 

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Hmmmmm...

I wouldn't condemn them yet and they are much to expensive to replace on a guess. I have no access to a scanner, but if you PM me with your mailing address I will snail mail you the info from the manual. In the meanwhile check your wiring and grounds and, if you can, try your modules on a running bike.
 

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Discussion Starter · #10 ·
Thanks for all your help. I emailed you my address, btw can you double check to make sure that the positive lead and negative lead you told me was correct. Like I said if I would of reversed them the units would have been shown as good.

Thanks
 

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That is what they have in the manual. The shop manual for my bike shows the same diagram, but the connectors are different. Then again, my owner's manual has several mistakes. That is why I suggested trying your modules on a running bike. The mail is on the way.

Oh, again, do check the grounds as ducpainter suggested. Transistors hate bad grounds.
 

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Discussion Starter · #12 ·
Thanks,

For your help, I'm still looking for the problem want to check everything before I order new modules. Haven't found any faulty grounds or wires yet. I did find out you can get the Ducati Performance upgrades for $188 a module. These advance the timing. Not sure I should go with them but they are recommended over the stock. Has anyone tried themm and does anyone have any other ideas what could be wrong besides the CDI units? Anything else I should check?
 

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The DP modules work fine on a stock bike, but if you ever go high compression the bikes run better with retarded timing. Have you checked around for used ones?
 

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Discussion Starter · #14 ·
Howie,

Thanks for the diagram. I have exhausted my search, so it must be the ignitor boxes. I found a used one pretty cheap should have it here in a couple of days and will be able to tell for sure if it is the ignitor boxes. I will keep you updated, so at least we all know if the manual is correct. I am still trying checking the bike's wiring for any shorts.
 

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Discussion Starter · #15 ·
Ok so I finally diagnosed the problem conclusively. I ended up purchasing a used ignitor box on the internet fairly cheap. When it arrived I tested it just like the diagram shows and it tested exactly like mine had tested earlier (read above). So I wasn't sure if that was going to fix the problem. This morning I hooked it to the horizontal cylinder and wooolaaah I had spark. So basically the service manual is wrong and there isn't a conclusive test for the ignitor boxes. After talking to many different people and my own experience the only way to test the ignitor boxes is to have a working spare. If someone is reading this having the same problem as I am, I recommend purchasing a Haynes manual if you don't already have one. Test each part in the igniton system according to the book and re-check. If this does not solve the problem, then it is probably the ignitor boxes. BTW if both ignitor boxes go out at the same time, it is most likely that something caused it and you should check the wiring throughout the bike for a bad ground. Hopefully this helps someone with the same problem. Thanks for everyones help.
 

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Glad you got it figured out. Did you find a faulty ground?
 

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Discussion Starter · #17 ·
The engine to frame ground on the right hand side had a loose nut. I also just put a new battery in the bike a few hundred miles earlier. I wonder if the added voltage and the loose ground caused it. Anyway if that was the cause it shouldn't be a problem anymore. I also checked the wiring harness on the right side of the bike, and everything seemed fine.
 

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It's interesting that on the newer bikes that don't use the boxes that the ground from engine case to frame is no longer used.
 
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