Ducati Monster Forum

Moto Board => Tech => Topic started by: Blue on June 29, 2010, 09:44:21 AM

Title: Tachometer not reading right?
Post by: Blue on June 29, 2010, 09:44:21 AM
I have a 2000 M900ie.  This is the first year of the fuel injection on the monsters and it came stock with a full set of gauges (no immobilizer, no gauge sweep).  The issue I am having is with the tachometer (electronic) not reading correctly in the upper rpm range.  The bike runs and idles nicely.  The idle is indicated at about 1000rpm.  The rev limiter kicks in at an indicated 7500rpm on the tach.  According to the manual, the limiter should start at 8600rpm (the stock ECU has been upgraded with a FIM chip).  This does this in gear on the road or in neutral sitting still. 
Anyone else have this problem or know what's up?  Perhaps a bad connection to the coils?
Thanks.
Title: Re: Tachometer not reading right?
Post by: Howie on June 29, 2010, 11:35:07 AM
My first step would be to check accuracy with a known good tach.
Title: Re: Tachometer not reading right?
Post by: ScottRNelson on June 29, 2010, 02:51:09 PM
The Ducati Performance tachometers used to get a bad ground connection on the circuit board.  The fix was to loosen the three screws at the back then tighten them up again.  Sometimes it fixed it and sometimes it didn't.  The tach that I added to my 1997 M900 was good at idle and good at redline, but jumped around between about 4000 and 7000 rpms.  I just learned to live with it.

I'm thinking that some dielectric grease where the screws attached might have improved things.

This may or may not help with your particular tachometer.
Title: Re: Tachometer not reading right?
Post by: Blue on June 30, 2010, 10:22:19 AM

Quote from: howie on June 29, 2010, 11:35:07 AM
My first step would be to check accuracy with a known good tach.
Swapping with a known good one is a good idea; is the Ducati a wasted spark set up?

Quote from: ScottRNelson on June 29, 2010, 02:51:09 PM
The Ducati Performance tachometers used to get a bad ground connection on the circuit board.  The fix was to loosen the three screws at the back then tighten them up again.  Sometimes it fixed it and sometimes it didn't.  The tach that I added to my 1997 M900 was good at idle and good at redline, but jumped around between about 4000 and 7000 rpms.  I just learned to live with it.

I'm thinking that some dielectric grease where the screws attached might have improved things.

This may or may not help with your particular tachometer.

It isn't a DP tach, just the stock one that came on the 2000 900ie.  Perhaps I will remove the back cover and clean things up a bit. 
Here is a photo.
(https://farm5.static.flickr.com/4014/4717608854_44fed56fa7_b.jpg)
Title: Re: Tachometer not reading right?
Post by: COP TZR on July 19, 2010, 07:02:14 PM
Quote from: ScottRNelson on June 29, 2010, 02:51:09 PM
The Ducati Performance tachometers used to get a bad ground connection on the circuit board.  The fix was to loosen the three screws at the back then tighten them up again.  Sometimes it fixed it and sometimes it didn't.  The tach that I added to my 1997 M900 was good at idle and good at redline, but jumped around between about 4000 and 7000 rpms.  I just learned to live with it.

I'm thinking that some dielectric grease where the screws attached might have improved things.

This may or may not help with your particular tachometer.

I sent you a PM in regards to the DP tach.  I get no reading from mine.  Can you help?
Title: Re: Tachometer not reading right?
Post by: ScottRNelson on July 20, 2010, 05:17:10 AM
Quote from: COP TZR on July 19, 2010, 07:02:14 PM
I sent you a PM in regards to the DP tach.  I get no reading from mine.  Can you help?
Reply sent.  No, I can't help much, since that bike has been gone since 2003.  Sorry.
Title: Re: Tachometer not reading right?
Post by: Blue on September 22, 2010, 11:09:17 AM
I took 45 minutes and when through the entire wiring harness with contact cleaner and dielectric grease, starting at the ECU and working my way through to the taillight and headlight.  I did not take apart the gauges yet; I wanted to see if I could pin point the issue as part of the harness (I was also trying to resolve another problem I was having with my Monster: Spitting through the intake on start up (http://ducatimonsterforum.org/index.php?topic=41361.msg739320#msg739320))
The only corrosion that I found was on a white connector, near the headstock and just above the horn (there are a couple there).  Really, everything else looked good.
At the start of the riding season, the limiter kicked in at an indicated 8250rpm, then after the bike was in a serious rain storm the limiter kicked in at an indicated 7500rpm and the last ride before cleaning the harness the limiter kicked in at an indicated 8250rpm again.  After going through the harness, the limiter kicks in at an indicated 8000rpms.
Time to take apart the gauges!
Title: Re: Tachometer not reading right?
Post by: Blue on September 29, 2010, 09:23:21 AM
I took the cluster apart and cleaned the 3 pin connector (which contains the signal wire for the tach) and the two bullet connectors with contact cleaner and then followed up with dielectric grease.  I took the bike out for a spin and spooled it up to the limiter which kicked in at an indicated 7500rpm again, so it appears that the tach is the problem. :-\
I haven't tried a known good tach as I don't have one (the VDST software would be helpful here).  Time to look at eBay and the classifieds. 
Title: Re: Tachometer not reading right?
Post by: Blue on October 01, 2010, 09:26:12 AM
Nothing new to report yet.  I did some more searching on the forum for possible solutions and ran across an answer to a question I had put forth in this thread.  I am assuming that the M900ie set up is the same for the 2000 and 2001 bikes as they have the same ECU (1.5 with no immobilizer).  

First question: Is the Ducati a wasted spark set up?
From: Re: anybody install this tach? (http://www.ducatimonsterforum.org/index.php?topic=7540.msg123612#msg123612)
Quote from: Drunken Monkey on July 21, 2008, 10:37:03 PM
The FI bikes ('01 +) have a "single fire" ignition vs older carb bikes that have a "dual fire" ignition.

Single fire means one spark every 2 rotations, dual fire means one spark every rotation.

So first off, I'm not sure which type of ignition you have, since you're right on the cross-over period between ignition types.

Once that hurdle has been crossed, wiring it up is pretty easy: Basically you tie the tach's input wire into the green or green/yellow wire going to one of your coils. Or if that color isn't the same on your bike, the "not grounded wire that isn't the spark plug wire"

But like I said before: The big question is what kind of tach is it, and does it match your bike's ignition type?
So, the answer is no, the FI bikes do not have a wasted spark (firing on the compression and exhaust stroke).  
So, if one were to take the FI gauges and move them to an earlier carb set up, they would have double the rpms due to twice the signal, correct?

And I thought this was interesting about the kickstand switch:
From: Re: I have a question on my tach-M900 (http://www.ducatimonsterforum.org/index.php?topic=24297.msg427963#msg427963)
Quote from: Drunken Monkey on May 26, 2009, 08:22:35 PM
That's... odd.

I know on the 2001 models the tach signal came in through the wire that used to be used for the kickstand warning light. Maybe you've got a short and/or crossed signal.

Then again, if you like the effect, why worry about it  :)
The reason I am interested in this is due to the previous owner removing the side stand safety start up switch.  I did not inspect this when I cleaned up the wiring.  I will have to look at this this weekend.

On the topic of the tach, I really like the Vapor gauge on the Monster.  I can't explain it...
Re: Trail Tech Vapor (http://www.ducatimonsterforum.org/index.php?topic=21737.msg388301#msg388301)
Quote from: lowd239 on April 08, 2009, 11:14:46 AM
Hmm "tach input" wire?  Im not exactly sure which wire that would be but I just bought a multimeter with an rpm sensor for 4-cylinders so perhaps that could show me if there was any kind of rpm signal from an unused wire.
The gauge looks pretty clean, but there arent enough lights for all of the gauge lights so I might just wire the low fuel and oil pressure to the same light.
Im also working on finding a good place for the temperature sensor location since under the sparkplug (as instructions say) puts too much of a bend on the copper end of the sensor.
(http://i511.photobucket.com/albums/s351/lowd239/ducati/DSC_0020.jpg)
Title: Re: Tachometer not reading right?
Post by: ducpainter on October 01, 2010, 09:30:41 AM
Quote from: Blue on October 01, 2010, 09:26:12 AM
Nothing new to report yet.  I did some more searching on the forum for possible solutions and ran across an answer to a question I had put forth in this thread.  I am assuming that the M900ie set up is the same for the 2000 and 2001 bikes as they have the same ECU (1.5 with no immobilizer). 

First question: Is the Ducati a wasted spark set up?
From: Re: anybody install this tach? (http://www.ducatimonsterforum.org/index.php?topic=7540.msg123612#msg123612)So, the answer is no, the FI bikes do not have a wasted spark (firing on the compression and exhaust stroke). 
So, if one were to take the FI gauges and move them to an earlier carb set up, they would have double the rpms due to twice the signal, correct?

And I thought this was interesting about the kickstand switch:
From: Re: I have a question on my tach-M900 (http://www.ducatimonsterforum.org/index.php?topic=24297.msg427963#msg427963)The reason I am interested in this is due to the previous owner removing the side stand safety start up switch.  I did not inspect this when I cleaned up the wiring.  I will have to look at this this weekend.

The first year of injected monsters used the wasted spark system. The only thing the ecu controlled was the fueling.

I'm pretty sure you'll see two Kokusan ignition black boxes mounted on the battery box next to the coils.

If that is the case the tach is fed from one of those coils or boxes
Title: Re: Tachometer not reading right?
Post by: Blue on October 01, 2010, 01:16:32 PM
Quote from: humorless dp on October 01, 2010, 09:30:41 AM
The first year of injected monsters used the wasted spark system. The only thing the ecu controlled was the fueling.

I'm pretty sure you'll see two Kokusan ignition black boxes mounted on the battery box next to the coils.

If that is the case the tach is fed from one of those coils or boxes
Thanks for the input DP, but the coils on the bike are mounted on the left hand side of the bike (Red Ovals).  The 2000 and 2001 bikes have the same ECU (1.5), so I assume it is a not a wasted spark system.

(https://farm5.static.flickr.com/4109/5042699574_af8de35f3b.jpg) (https://www.flickr.com/photos/42621367@N05/5042699574/)
Title: Re: Tachometer not reading right?
Post by: ducpainter on October 01, 2010, 01:25:53 PM
Quote from: Blue on October 01, 2010, 01:16:32 PM
Thanks for the input DP, but the coils on the bike are mounted on the left hand side of the bike (Red Ovals).  The 2000 and 2001 bikes have the same ECU (1.5), so I assume it is a not a wasted spark system.

(https://farm5.static.flickr.com/4109/5042699574_af8de35f3b.jpg) (https://www.flickr.com/photos/42621367@N05/5042699574/)
Maybe it's 99 I'm thinking of, because there was a monster that had FI and the old style ignitors.

If it has the coils mounted on the side it is not wasted spark.