Running on one cylinder

[Mobius]

Shees! The bike ran fine for about 6 days of happy motoring, but then one cylinder would cut out periodically, and then cut back in again. Now when I start it, its running on one pot only. The last ride saw me do about 4 klicks on just the one cylinder, limping home.

Brand new Champions installed.

The high tension leads appear to be attached correctly, and refitting them doesn't fix the issue.

I guess my next mission is to yank one HT lead at a time, to see which pot isn't firing - so once I find that - what do I check next?

I did quite a bit of reading here, but my symptoms are not the same as others who report intermittent misfires when electrical gear is turned off and on. It makes no difference if I have lights on or off, or indicators running or not.

OH - and Merry Whatsit to all!

[jcslocum]

Pull the plug and see what it look like. Maybe something simple, like a fouled plug...

[907pasonut]

I second that...most of the problems are electrical...I would take both plugs out, connect them to their leads and earth the plug bodies and crank the engine over to see if you are getting a good spark...and work your way back from there, plug-lead-coil-wiring...etc
...all the exitement of owning a ducati

[paso750]

Could be also a combination of things such as some electrical and the carbs not being synchronized well.
First thing I`d try is to swap the coils and see if the other cylinder then drops out or if it`s still the same one.

G.

[Mc tool]

Mobius , there is a paso on trade me as Im sure you will know , as will the other kiwi paso nuts,( sorry Fraser , I dont think its got nice oak wood grain mufflers ), down to 2.5k$ and its been there a while , maybe the owner will part out

[Mobius]

OK, I am starting to feel like my Duke is very similar to my Porsche: Things fail for no apparent reason, and then are fixed for no apparent reason. Either by intervention, or without it.

I removed the spark plugs, inspected them, found them to be in pristine condition and refitted them. Started the bike: it runs perfectly. Covered 100 Klicks - no misfiring at all.

Go figure.

Today my Starter Upgrade kit arrived: the cables are just beautifully made, and I'll fit them over the next day or so. I'm looking forward to some more powerful cranking, and more reliable starting from cold. I'll report my experience when fitted.

The next job I do will be to replace the coils - that definitely sounds like a good upgrade.

Thanks - as always - for the advice gentlemen!

[jcslocum]

You get the cables from MotoLectric???

[higgy]

OK, I am starting to feel like my Duke is very similar to my Porsche: Things fail for no apparent reason, and then are fixed for no apparent reason. Either by intervention, or without it.

Somewhere you have a connector needs some attention. Start at the switch and work your back to the ECU and from there to the coils. Don't forget the kill switch. Guaranteed you will find a problem If it is a terminal replace it and be sure not to forget those troublesome locking tangs. If the connector is melted replace it as well. On my 906 I have added a wire tie to the ears that holds the electrical terminals to the switch. Have not been stranded since or had battery issues since. Since I replaced the terminals and connectors and some wires along the way to and including at the ECU I have not had a dropped cylinder or even missed a beat at any rpm. I also had some o-ring issues on the weber DCNF at the same time but you won't have that issue on your 907. No matter how pretty it all looks on the outside you have to inspect every connector and every termination they hold for the entire circuit. Time well spent as you will enjoy many more years of trouble free riding. While you are at it check every ground,grounds, any ground anywhere can cause the strangest of intermittent issues.

[Mobius]

Yes, I got the MotoLectric starter cable upgrade. I have never seen or felt finer cables in my life. If they work as well as they look and feel, then they will be stunning.

I plan to ride the bike (it is a 906) for the rest of the summer barring any more failures or problems, and then spend some time over winter tracing possible electrical faults, attending to all connectors and at the same time will replace the coils, too.

I'll probably replace the headlight wiring at the same time, as well: it doesn't seem as bright as it should be, and I like a bright headlight!

The engine still has that bit of loose metal floating around in it, as an occasional crunch is felt in the first 10 seconds of running. I have not yet decided if I can motivate myself to have it stripped and cleaned to locate and remove it - as this would be a very expensive process (I do not have the facilities, the inclination nor experience to do the job myself) - but balanced against the price of buying another 906 to get a motor from...

Perhaps it'll eventually get thrown into a intake and end up in the filter, or trapped somewhere it can't damage anything. I am pretty confident it is inside the gearbox.

[higgy]

you can find great affordable headlight wiring kits from this guy
http://easternbeaver.com/Main/main.html

first rate bolt on kits...I have them on both bikes with the dual yamaha headlight. On the 907 i installed a switch which allows me to turn off the low beam as well
btw the motolectric kits work great, I have them installed on both the 906 and the 907

[Antzo]

Just a few days after the service and today I experienced some misfiring paf! paf! paf! ( bloody classic machines can't live with them can't live without them ).

I have read the above and tomorrow I will start the search of the bad connection.

I want to ask those guys with the long experience, which type of spark plug do you suggest as most reliable?? I am whiling to sacrifice performance for reliability if needed!!

[persempre907]

...I have the battery light off on my red 907.
Replaced the lamp on the dashboard, she's always off...
Grrrrrrrrrrrrrrrrrrrr.
Ciao

[persempre907]

I will start the search of the bad connection.

I want to ask those guys with the long experience, which type of spark plug do you suggest as most reliable?? I am whiling to sacrifice performance for reliability if needed!!

...I have the battery light off on my red 907.
Replaced the lamp on the dashboard, she's always off...
Grrrrrrrrrrrrrrrrrrrr.
Ciao

P.S. the NGK are great, as the Champion. No problem with any spark plug.