Recurring dropped cylinder.

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Mobius
Posts: 100
Joined: Thu Jan 21, 2010 2:22 am
model: 906 Paso
year: 1990
Location: Christchurch, New Zealand

Recurring dropped cylinder.

Post by Mobius »

Intermittent faults are VERY annoying. This one's a right B*stard. If I can solve this problem permanently, I'll be very happy indeed.

Symptoms:
* Only seems to happen when bike is warm.
* Cylinder just cuts out. Doesn't surge and stop.
* Stopping the bike killing the ignition and restarting does not affect it.
* No electrical equipment, on or off, seems to affect it.
* Revving the bike up to 6,000 or so in neutral sometimes seems to bring it back.
* No apparent rhythm to the cylinder outages; either within a ride, or from ride to ride. At least 2 weeks since it last misbehaved.

Details:
* Plugs less than 1,000 kilometres old.
* Starts and idles beautifully.
* Runs fabulously, and then.... not.
* 95 RON fuel. Tank fullness does not seem to be a factor.

When the cylinder drops out, it doesn't *try* to fire up again - it's like it's just switched off.

I know G posted a nice diagram of a circuit modification for increased reliability, but I can't seem to find it. What I'm looking for is a good, long-term solution. If there is one. :P
How many escape pods are there? "None, Sir!" You counted them? "Twice, Sir!"
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higgy
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Re: Recurring dropped cylinder.

Post by higgy »

Replace the o-rings on your idle screws, or spark wires could be either one or it still could be the switch
You gotta dig in and do the dirty work, wishing won't help :mrgreen:
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
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Mc tool
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Re: Recurring dropped cylinder.

Post by Mc tool »

Do you know which pot its dropping , if you do you can swap some parts from one cyl to the other ( coils plug leads ) and see if the fault moves with the swapping of the part. Im thinkin that seeing as how its been a couple of weeks sinse the last failure its unlikely to be a faulty component in the module or a coil getting hot and failing, more likely to be a bad connection somewhere :)
I wish I was young again............Id be heaps smarter than last time
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higgy
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Re: Recurring dropped cylinder.

Post by higgy »

bad connection somewhere :)
How unuusual :drunk:
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
88 750
90 906
92 907ie
Mobius
Posts: 100
Joined: Thu Jan 21, 2010 2:22 am
model: 906 Paso
year: 1990
Location: Christchurch, New Zealand

Re: Recurring dropped cylinder.

Post by Mobius »

I am about to begin Higgy's suggestion of the ignition switch. I have no idea how to remove it, and the manual isn't any help. I guess I'll just muddle through. *sigh*

The failing pot is the top one - naturally. *double sigh*.

Now, where to find a diagram and a-fool-could-follow-it method of inserting a relay in the ignition circuit?
How many escape pods are there? "None, Sir!" You counted them? "Twice, Sir!"
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higgy
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Re: Recurring dropped cylinder.

Post by higgy »

Its all here,just got to poke around, if you can't find it let us know, someone will point you to it

http://forums.ducatipaso.org/viewtopic. ... tch+Repair

Check the FAQ's and the Documents they are up to date :thumbup:
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
88 750
90 906
92 907ie
Mobius
Posts: 100
Joined: Thu Jan 21, 2010 2:22 am
model: 906 Paso
year: 1990
Location: Christchurch, New Zealand

Re: Recurring dropped cylinder.

Post by Mobius »

I couldn't figure out how to remove the ignition switch unit. A mirror shows there's no way to undo it from below. I unplugged the circular plug from the bottom of the switch, and it all looked pretty decent, but I cleaned the contacts and the pins and reassembled it. It went back in nicely.

Now it has a new symptom, though: starts on one cylinder. :(

How do I remove the ignition switch unit?

I saw G's guide and am confident I can service the thing correctly and easily once I get it off.

Not having a great today: a crazy Indian ran a red light and hit my Porsche in the rear left quarter. ACK. Still, I'm on annual leave. Musn't grumble.
How many escape pods are there? "None, Sir!" You counted them? "Twice, Sir!"
Mobius
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Joined: Thu Jan 21, 2010 2:22 am
model: 906 Paso
year: 1990
Location: Christchurch, New Zealand

Re: Recurring dropped cylinder.

Post by Mobius »

OK, got the ignition switch out, but it is not the same as shown in the guide Higgy pointed me to. Mine has a plug and socket arrangement on the base, and when I remove the plug, the white plastic socket portion is mounted in the ignition housing with dents in the alloy housing.

I fear I will break it if I try to force it.
How many escape pods are there? "None, Sir!" You counted them? "Twice, Sir!"
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higgy
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Re: Recurring dropped cylinder.

Post by higgy »

Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
88 750
90 906
92 907ie
Mobius
Posts: 100
Joined: Thu Jan 21, 2010 2:22 am
model: 906 Paso
year: 1990
Location: Christchurch, New Zealand

Re: Recurring dropped cylinder.

Post by Mobius »

Yes thanks Higgy! My ignition switch connector looks nothing like that awful thing - it's pristine clean with no heat markings whatsoever.

I went the whole hog, and unplugged every connector in the ignition loop, cleaning every surface as I went using contact cleaner WL and 60 to clean off deposits, and 600 grade paper where I could reach.

Now the bike starts on both.

Time for a ride, to see if problem licked!
How many escape pods are there? "None, Sir!" You counted them? "Twice, Sir!"
Mobius
Posts: 100
Joined: Thu Jan 21, 2010 2:22 am
model: 906 Paso
year: 1990
Location: Christchurch, New Zealand

Re: Recurring dropped cylinder.

Post by Mobius »

Just got back from a 120km run, and the bike ran like a clock.

The loudest clock the world has ever known.

:beer: To everyone for pointing me in the right direction. Thanks, all!
How many escape pods are there? "None, Sir!" You counted them? "Twice, Sir!"
nnnnnnorman
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Re: Recurring dropped cylinder.

Post by nnnnnnorman »

excellent! i bet you enjoyed that ride! :thumbup: :cool: :)
1990 906 paso red and white
1991 906 paso black and gold
1997 ST2 red
2004 ccm r30 with 710 conversion
175 moto morini road race replica
a box of bits r100 bmw scrambler project
1962 rover 95 p4
1997 iveco daily
a non running xt600...stator needed
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higgy
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Joined: Tue Jul 29, 2008 9:50 pm
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Re: Recurring dropped cylinder.

Post by higgy »

that is why we all come here,over and over :cool:
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
88 750
90 906
92 907ie
User avatar
higgy
paso grand pooh-bah
Posts: 3378
Joined: Tue Jul 29, 2008 9:50 pm
model: 907 I.E.
year: 1992
Location: Hilltown,Pennsylvania
Contact:

Re: Recurring dropped cylinder.

Post by higgy »

Mobius,just FYI
When mine started acting up it was just a hiccup at cruise. Only occurred once in a while. In the end it progressed to the point it left me stranded on the side of the rode. I've been fixin vehicles and automated equipment professionally for 35 years plus and only been stranded on the side of the rode a few times, but that one hurt, had to call the wife and son to rescue me :drunk: :phone: :roll:
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
88 750
90 906
92 907ie
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