no spark 906

discussions specific to the 906 Paso
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badhabrace
Posts: 21
Joined: Sat Feb 05, 2005 12:00 am
model: 906 Paso
year: 1990
Location: USA

no spark 906

Post by badhabrace »

I need advice. Last season I lost spark at the rear cylinder. I replaced the coil,bike ran for about 7 minutes,stalled and hasn't started since. With some tips from Gerhard, I have determined that while attempting to start the bike,voltage drops to 9.74 volts at the Digiplex unit. I have a sneaky idea that this maybe part of my problem. I have tested the pick-up & my battery has 12.76 volts in it. Any ideas??? Should I invest the 100.00 in a starter upgrade wiring kit? Your input uis GREATLY appreciated,THANKS
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907pasonut
paso grand pooh-bah
Posts: 604
Joined: Tue Jul 20, 2010 9:27 am
model: 907 I.E.
year: 1992
Location: Melbourne Australia

Re: no spark 906

Post by 907pasonut »

I think the voltage dropping to 9.74 volts at the digiplex during start up is normal (from a standard motorbike battery) as the starter motor is sucking up a lot of current cranking the motor.
I would check and replace leads and plugs, if they haven't been replaced for a while :dunno:
Cheers Claude.

...long live the square framed duc!

'92 907...numero 2046
'92 851...in progress
Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: no spark 906

Post by Mc tool »

I think that badhabrace is onto it. I found that with mine that a drop in voltage will cause the digiplex to temporaraly chunder, like when I switched on the headlights the thing would backfire but recover almost immediately even tho the headlight remained on. Try hot wiring the digiplex by running a wire from the batt + to the power input to the digiplex to prove the fault . the culprit is most likely either the main harness plug to the right hand switch block or the kill switch or even the ignition switch itself . Do a volt drop test and you will see .
I wish I was young again............Id be heaps smarter than last time
badhabrace
Posts: 21
Joined: Sat Feb 05, 2005 12:00 am
model: 906 Paso
year: 1990
Location: USA

Re: no spark 906

Post by badhabrace »

Mc tool wrote:I think that badhabrace is onto it. I found that with mine that a drop in voltage will cause the digiplex to temporaraly chunder, like when I switched on the headlights the thing would backfire but recover almost immediately even tho the headlight remained on. Try hot wiring the digiplex by running a wire from the batt + to the power input to the digiplex to prove the fault . the culprit is most likely either the main harness plug to the right hand switch block or the kill switch or even the ignition switch itself . Do a volt drop test and you will see .
I tested that today,ran 12 volts to the box and got GREAT spark! I am going to re-wire the battery,ground and starter tomorrow and see what that does. If not,looks like I will be getting the starter rebuilt. Thanks a ton!!!
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persempre907
paso grand pooh-bah
Posts: 3312
Joined: Tue Dec 06, 2005 12:00 am
model: 907 I.E.
year: 1992
Location: Roma, Italia

Re: no spark 906

Post by persempre907 »

Clean all the electric connections and replace the bad ones.
I don't think it was a starter issue.
Ciao
Francesco
Ducati 907IE 1992 Rosso
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Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: no spark 906

Post by Mc tool »

persempre907 wrote:Clean all the electric connections and replace the bad ones.
I don't think it was a starter issue.
Ciao
me neither. There is a bad connector somewhere between the battery and the digiplex. Get a wiring daigram and follow the flow from the battery to the digiplex . if there is a connector , set multi meter to DC volts and put one probe on either side of connector ( power on ) , you should get 0 volts . If the meter says ( for arguments sake ) 1.5 v , then you are loosing 1.5v over that connector. Start by putting one probe on the batt + and the other on the digiplex power in wire . the displayed voltage is what you are loosing between the batt and the unit and it should be minimal , no more than 0.5v. The unit will run on about 9 -9.5 v but when you opperate the starter the combination of the normal starter drain and any faulty connector will lower the voltage to the point where the digiplex wont work properly . The main culprits are what I said in my last post
I wish I was young again............Id be heaps smarter than last time
dave906
Posts: 32
Joined: Tue Apr 11, 2006 12:00 am
model: 906 Paso
year: 1990
Location: Canberra, Australia

Re: no spark 906

Post by dave906 »

Agree with McTool.
I have had voltage drop problems with both the ignition switch and the kill switch.
The wire soldered to the kill switch terminal was fractured to the point where there was just one or two strands of the wire left hanging on when I found it.
Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: no spark 906

Post by Mc tool »

If you have a look at my "Wired Paso ( owner )" thread you will see that I have fitted a couple of relays . the top one feeds the digiplex and the coils . The relay is activated by the brown wire coming from the rh handle bar switch ( previously only fed the digiplex ). Both the relays you see are fused relays and are connected to the battery ( red cable going round the back of the fuse box in pix .... also feeds fuse box ) the other ( lower ) relay is the main relay which now feeds into the green / black wire . This relay is activated by a feed from the ignition sw ( small red wire on rh side of fuse box) Just make sure you feed the correct side of the ign sw or your park lights wont work .
Pink wire from fuse box feeds the fan via thermostatic sw , brown wires ( paired together ) are from reg , and red wires feed head light relays which are right up by the headlight . I am going to replace the battery cables too as I have previously been caught out by a faulty earth cable on my SS.... cost me for a battery and a set of starter motor brushes before the penny dropped :banghead:
I wish I was young again............Id be heaps smarter than last time
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