ONLY FIRING ON 1 CYLINDER

[LAZOON]

One of my cylinders just stopped firing the last 4 miles of my journey home on My 1999 @ (36,000 mls).
10 mins later after I limped home on 1 cylinder I started her up & she was running normally on both cylinders.
I would appreciate it if any of you have come across this problem yourself & could help me track down what I believe is the start of a component
beguining to fail.
I have recently change my fuel pump for a pattern part one as I spent out
£158 for a genuine Honda pump last year & which only lasted 15,000 miles, My new alternative fuel pump is only a month old & is working perfectly.
I also changed the spark plugs just a couple of weeks ago so I've ruled out 2 of them failing as a cause to this problem.
My first thought when the problem started was that it could be the COIL as each COIL powers a pair of spark plugs.
My workshop manual circuit diagram revealled a C.D.I. & now I'm wondering if that component is starting to fail.
As I travel 52 miles a day, I feel that I want to nip this problem in the bud before the faulty component fails for good & I get stranded on the Motorway.
I spent all day today checking & cleaning every connector in the bikes wiring loom just to see if I came across a corroded contact, but as I always take the time to spray WD40 on any connectors that I come across when servicing that area of the bike, I did not find a fault there.
the annoying thing is that the bike is now running fine, but for how long!
any suggestions to what it may be would be appretiated.

[Tikka]

It could be a faulty CDI or just a loose connector on your CDI. Also heard that loose connectors on the battery could cause this problem.

[BobA]

I know I may be well off target here, but I had a similar problem with a Ducati a few years ago. This is an old'ish Duke, so everyone immediately thinks, electrical, build quality etc, but it was quite a straightforward one on this occasion.

I'd just filled up with fuel, she started coughing a mile or so later, then gave up. A few minutes later, she started, run a few hundred yards, then stopped again.

The problem?

The fuel I'd just added was full of ****ey glooop. This was sloshing around, pumping as far as the filter, clogging, and as soon as the engine stopped, it would all flush back out of the filter into the tank, until the engine was started again and it was sucked back in again!

You've started well ny looking at the basics, but it might not actually be electrical. Check the fuel filter, lines, tank, cos it might be fuel starvation due to a blockage, or worse if its made it past the filter to one of the carbs.

Just an idea, I hope it helps.

Regards

Bob

[YEN_POWELL]

I've had this on the front cylinder. It was the terminals on the front coil, they get more affected by the weather than the rear which is all warm and snug under th seat/tank.

Just pull the two spade connectors of the spades on the front coil, then get a file or a knife and scrape them till they are bright again. This cured mine (about a year back now and 20,000 miles ago)and was really down to riding every day in all weathers, especially when I removed the 2 rubber strips that hang down the front of the frame down tube.

My symptoms were exactly as you describe, sudden loss of power and loss of spark on front cylinder, then fine next morning or after it all cooled down.

If I could be bothered I'd swap the two coils around and give the front a rest and expose the rear instead to some real weather.

[LAZOON]

Hi Yen_Powell,
I've just ridden 17 miles this morning & have had no miss-firing at all.
When I was cleaning the connectors, I also did as you suggested & cleaned the COIL spade contacts, I did this using a toothbrush soaked in WD40 & then pushed the spade terminals on & off half a dozen times to clean the contact area further still, in fact I did this to every connector on the bike yesterday, then finally I gave the mated connector a nice spray of WD40 around the outside of the connectors.
I think that you may have "hit the nail on the head", time will tell.

Regards
Lazoon.
[/b]

[YEN_POWELL]

I did mine with a wire brush the first time and the problem returned after a few months which is why I switched to using the file/knife routine, it's been okay since though, especially as I replaced the rubber strips which protect the coil and front plug from road spray.

[Dilbert]

I love the smell of WD40 in the morning