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My Paso 750 from '86 is already standing in my shed for 6 weeks now. I can't get her running anymore. She turned me down on the first drive of the year. I tell the whole story to make the analyses a bit easer.

Already had problems starting because of a lame battery but managed to push her on (so you would think the ignition stuff is ok then). After some 20 kilometers I mentioned backfire and she started running on one cilinder. After some hundreds of metres the running cilinder didn't manage the job either and she came to a hold.

Tried to start her up by pushing and with a powerpack but that was a no go. Had the idea that the fuel pump wasn't ticking. Already had some problems with bad running last year.

So brought her home on a trailer. Now I have the panels of and ofcourse checked the carbs (dell'orto phm40) but I have fuel also no problem with the tank pulling vacuum and the fuel pump is running.

Loaded the battery and that is showing a stable 12.8 Volts. The starter engine is running fine and I have light and dashboard indication. All the fuses are ok to.

However when check the spark on both pluggs there is only a little serie of sparks at the turn of the ignition key. There are no sparks when using the starter engine and also no spark when I push the bike to get a signal from the pick-ups on the flywheel. Maybe the problem is the starter engine pulling to much power.

Now the measuring details. All wiring show little resistance so I asume there is no wiring damage or bad connection. I'm measuring a signal from the pick-ups when starting. Pulses in the order of 80 to 90 mV (is that ok?). I'm getting 11,1 V over the coils which drops to 7,6 V when using the starter engine (this is the mean circuit?). How can I measure the pick-up signal which I guess are amplified in the electronic boxes (kokusan) under the saddle at the coils? Next to this I measure a resistance of exact 99 Ohms over the pick-ups when it should be 220 Ohm according to the workshop manual. But both pick-ups show exactly the same resistance so my guess that there not broken.

I would also like to check the resistance of the high and low voltage part of the coils but don't know how and were to measure.
In the end I'm a bit lost. There is to little power at the coils when starting and I'm not sure if these should get a signal from the pick-ups and how to measure this.

I'm thinking of upgrading the wiring like John Slocum did but am unable to download his shedule (I've mailed you John so could you send it to me?). Hopefully there am some answers to the questions in this long story and I'll be able to get her running again.

kind regards,

Remko Spenkelink, Nijverdal, The Netherlands.
Paso144.

Hi,
have you checked the pick-up on the flywheel (RPM sensor)?
I had a similar problem on my 906.
Ciao

Did you check the quality of the gasoline after you winterstop?
Is the fuelline and filter clean?
Succes

7.6 volts over the coils while the starter is running is a very low measure... also 11.1 is not good... maybe some trouble inside the main switch (key lock) that you can test close to the fuse box.
In this case, an electrical bypass on the wiring can solve the trouble

Thanks guys for the info,

I've already checked the fuel and asume that's not the problem because I rode for 20 kilometres before she died on me.

The pick-ups are checked. They give a signal/pulse of 80 to 90 mV but I don't know whether thats enough. There resistance is low compared to the workshopmanual (220 Ohm) but both give an exact measure of 99 Ohm.Thats to much of a coincedent, so I asume there working ok.

Before I can do a electrical bypass I need some clear shedules because I'm no electrical genius. I understand that John Slocum made such a shedule in pdf format but I'm not able to download it. So if anyone could send me shedule that would be great.

regards Remko

Remko,

disconnect the orange leads to the coils

connect one to a relais (normal 4 contact car relais you can get everywhere)

isolate the second end of the orange cable (it`s not needed)

run a wire from the battery or starter relais (with an inline fuse) directly to the relais (this will give you full voltage back)

make a cable to connect the relais to ground (the frame)

make an Y-lead to connect the 2 coils to the last free relais contact.

that`s it.

Maybe you have problems with wiring connection: there are two plugs you must ceck: the one out from the main switch and the other from the engine stop in the right handle


and here are the suggestion to restore the main switch

"I hope I can suggest you something about ignition switch:
0)ENSURE YOURSELF TO BE A GOOD WATCHMAKER (or to have a spare part aviable!)
1)Disconnect the switch from the main electrical plant
2)Remove it from the steering plate, so you can work on your desk
3)You can see three little plastic grapple in the bottom cap
4)Open it very slowly and take care not to loose springs, balls and nuts (they are very small!)
5)Clean from rost and dirth, lubrificate with special white grease
6)Re-assembly everything (this can be very HARD!!!).
7)be careful in putting the balls in their right place

Hope the next time I'll be able to put images in the site, so I'll show you how to build a real bypass relay

I fixed the link to the wiring upgrade. Sorry about that. The wonders of computers!!!

The link to the instructions is:http://www.frontiernet.net/~jcslocum/

He guys,

Finally found out what the problem is. I've blown away my cdi units with a starter battery. So never use such a powerpack or related item because it will sure kill you're electrics. Strange thing is I ever heard about it till I start calling dealers and strip yards for replacement cdi's. Common remark 'O you've put a starter battery on it', or 'No we don't have cdi's because in the springtime everybody blows them away with starter batteries'.

So now I'm looking for used cdi boxes of Kokusan or the replacement parts of Ducati Performance (AL-9000). If you have a pair lying around please let me know on remko.spenkelink@wanadoo.nl.

greetz Remko

paso144 wrote:He guys,

Finally found out what the problem is. I've blown away my cdi units with a starter battery. Common remark 'O you've put a starter battery on it', .


greetz Remko

This is more common than is mentioned or thought, it happend to me a while ago and the mechinic said he has seen it a lot, the PASO CDI's are weak when being jumped or crash starting the bike, i went and got a SS CDI put onto mine with new matching coils and flywheel pickup, that wont happen agin now!!!!!

You can even search for a couple of ducati performance units by pedercini, that are the same sold aftermarket for newer carb engines
However, here's a link for a good electrical bypass