Sigh...Still Single

[delagem]

Dammit! My Paso is still doing the "running on one cylinder" thing...

Went thru fuel system, cleaned carbs, nothing wrong.

I believe I've isolated it to the forward cylinder. A timing light shows a nice steady strobe on the vertical cylinder, but there's a miss on the forward cylinder.

Now here's the strange part. I've swapped every component, front to rear. I switched the wires on the coils, and then switched the spark plug leads. No change. I even pulled my spare pickups out of my junk motor, and swapped them. No change. I swapped the Kokusan boxes. No change. No matter what I change, the miss still shows on the forward cylinder.

I mean, what's left?

The only thing I couldn't switch was the Blue/yellow wire, which I checked with a Fluke meter, .2 ohms, reading good.

I'm really open to suggestions here!

[higgy]

Take a good look at the o-rings on the ldle circuits,If they are not perfectly round and flawless they can cause this sort of issue.

[delagem]

Take a good look at the o-rings on the ldle circuits,If they are not perfectly round and flawless they can cause this sort of issue.

Thanks for the reply. Does this apply to Weber or DellOrto? I'm running DellOrtos... Didn't notice anything unusual on the o-rings, all jets clear, all passages clear.

What spark plugs are you guys running? Book says RA6YC. That's discontinued. Champion now lists a RA6HC as the replacement, stock #809. I'm currently running NGK DR8ES-L plugs, what supposedly crossed over.

I'm trying the RA6HC today now that I've done a little better homework....

[higgy]

It would apply to any carb,without good orings the idle mixture will be way too lean.........very likely causing a misfired or dead cylinder
I use the NGK as well,many here swear by the Champions

[delagem]

the idle mixture will be way too lean.........very likely causing a misfired or dead cylinder

I neglected to mention that this is noticeable at high speeds mostly. I'll be riding along at 70mph, and all of a sudden it feels like it "drops" a cylinder. Occasionally it will cut in and out, other times it's just out.

During my latest round of troubleshooting I noticed the difference in the flashing of the inductive timing light. One nice and steady, the other somewhat intermittent.

It's possible that the timing light issue isn't even related to the miss, however.

[higgy]

Different story, Number one suspect on any Paso with a high end
miss is voltage supply to the coils. For 5usd you can get a digital led display and wire it to one or both coils and monitor the voltage or if you have a fluke set it on record and go for a ride,static test may not necessarily uncover some voltage drops. cheap led here http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0501636451
I have these all over the place,as about a cheap as they come and very accurate in most situations.

[delagem]

Different story, Number one suspect on any Paso with a high end
miss is voltage supply to the coils. For 5usd you can get a digital led display and wire it to one or both coils and monitor the voltage or if you have a fluke set it on record and go for a ride,static test may not necessarily uncover some voltage drops. cheap led here http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0501636451
I have these all over the place,as about a cheap as they come and very accurate in most situations.

Interesting. I did check my voltage while engine was off yesterday, and only 9v to coil with the key in "on" position.... I've read a bit about the relay fix for the coil voltage, might have to give that a try.

[higgy]

9Volts off? I'd say you found your problem. We have a relay mod included in our Weber.doc and there is much here in the F.A.Q.'s

[delagem]

9Volts off? I'd say you found your problem. We have a relay mod included in our Weber.doc and there is much here in the F.A.Q.'s

Higgy, quick question. I couldn't find the mod instructions, I simply routed a hefty wire to a relay, 2 wires split with one going to each coil where the orange wires connected (2 orange on one coil, 3 on the other). I used one of the coil wires as a trigger, and a ground from the relay to the coil mounts. Sound right?

I set it up and now have 12.4 volts to each coil, but haven't taken the time to test drive yet.

[delagem]

YAHTZEE!

It's probably too soon to be celebrating, but I'm going to anyways! Ran just fine on the test drive this evening. (of course, this will be time #4 that I think I've found the problem, only to have it recurr a few days later!)

I'm a little perplexed as to why it was fine for 22 years with the cheesy coil wiring, and chose now to start acting up, if this is indeed the problem.

Higgy, Jon, anybody else involved with my various threads or the "wiring upgrade" posts, I owe you guys a beer!

Thanks a bunch,

Michael

[higgy]

Glad to hear you got to the source of "ONE Electrical ISSUE"
Now the fact that you found that one means there are many more. The fewer you take care of the quicker you will find yourself looking for an ignition module or a voltage regulator or an ignition switch..the usual expensive and hard to find parts that could and can yet be saved by checking every single ground and terminal for a good clean contact. In the worst case scenario you will watch your beloved Ducuati burn at the side of the road assuming you managed to get to the side of the road without incident. While at it dont forget to look at the wiring beyond any connection you fix. Electrolytic migration from the battery can severely compromise any wire. Not trying to scare you just enlighten you so that you can enjoy many trouble free hours of time with your Ducati of choice. A few hours spent here can pay major dividends down the road...

[delagem]

"Burn at the side of the road." LOL! I'm guessing you saw my AMA debut back in 2000 at Mid Ohio? Friggin' cheesy plastic foats on the Malossi carbs (DellOrtos) on my 900ss Pro Thunder bike.... That bike was a fireball!

I did replace every ground under the seat/engine, as well as a bunch of wiring on my rectifier. Thanks for the advice and help.

Michael

[jcslocum]

Mike,

Here is a link to the wiring upgrade thread:

http://forums.ducatipaso.org/viewtopic.php?f=1&t=173

You are just getting corrosion in the wiring and connectors is all. Time to clean every connection and the ignition switch as well as the kill switch.

[higgy]

I'm a little perplexed as to why it was fine for 22 years with the cheesy coil wiring, and chose now to start acting up, if this is indeed the problem.

Corrosion,years of it. As Jon stated time to clean it up,relay mod helps keep the strain on the components to a minimum in the process