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Quote from: 53Indian on April 14, 2025, 18:29:31 PMI'm sure you've tried this, but did the ecu fault code flash anything up?
Only in the past, and it was the fuel pump which I ended up replacing.
I'm sure you've tried this, but did the ecu fault code flash anything up?
Quote from: Bucko on April 10, 2025, 12:54:01 PMJust thinking outside the box.... assuming you have the plugs contacting cylinders, maybe they spark once when you hit the starter but then due to the cranking vibration they lose contact and don't spark?
Good thought, but I have my buddy holding up the bike and pulling in clutch and holding the start button for me. I'm definitely making contact so that isn't it.
Such a weird issue.
Quote from: Dustywolf on April 09, 2025, 23:53:53 PMI'd think that's part of my issue (having all the plugs out, or 2 at a time out) but that still does not really explain why it only sparks ONCE when I press the starter button.
It makes me think something is telling the ECU "hey, shut off spark."
Just thinking outside the box.... assuming you have the plugs contacting cylinders, maybe they spark once when you hit the starter but then due to the cranking vibration they lose contact and don't spark?
Quote from: Bucko on April 09, 2025, 22:05:19 PMJust to clarify, the motorcycle 'ground' is 'floating' with respect to a dual fire coil output and is not strictly required for the plugs to fire (except in that it provides an electrical path for a pair of plugs in the same cylinder). The plugs don't fire from coil to ground, rather the complete fire path is from : coil > wire > plug 1 > motor > plug2 > wire > coil (the same coil) - interrupt any part of that path and neither plug fires.
If you have both plugs out, you need to connect them somehow in order for them to complete the circuit and spark.
I'd think that's part of my issue (having all the plugs out, or 2 at a time out) but that still does not really explain why it only sparks ONCE when I press the starter button.
It makes me think something is telling the ECU "hey, shut off spark."
Quote from: Troll on April 09, 2025, 18:53:20 PMHere is the ign system wiring diagram. I still think you have flooded the engine. The waste spark system relies on at least one clean plug per coil in order to work. If there is no path to ground through an ionized air gap, the spark will not happen. Keep in mind, the spark jumps from the ground electrode to the positive electrode on one plug and from positive to ground on the other plug. All waste spark systems are like this, whether it's a Honda, a Harley, or a Chevrolet. It may be hard to visualize, but that's how it works.
Just to clarify, the motorcycle 'ground' is 'floating' with respect to a dual fire coil output and is not strictly required for the plugs to fire (except in that it provides an electrical path for a pair of plugs in the same cylinder). The plugs don't fire from coil to ground, rather the complete fire path is from : coil > wire > plug 1 > motor > plug2 > wire > coil (the same coil) - interrupt any part of that path and neither plug fires.
If you have both plugs out, you need to connect them somehow in order for them to complete the circuit and spark.
Quote from: Troll on April 09, 2025, 18:53:20 PMHere is the ign system wiring diagram. I still think you have flooded the engine. The waste spark system relies on at least one clean plug per coil in order to work. If there is no path to ground through an ionized air gap, the spark will not happen. Keep in mind, the spark jumps from the ground electrode to the positive electrode on one plug and from positive to ground on the other plug. All waste spark systems are like this, whether it's a Honda, a Harley, or a Chevrolet. It may be hard to visualize, but that's how it works.
I am not flooding it... because the spark plugs are outside of the engine.
Its a super weird issue, especially now that it's acting different with the new VDS.
Here is the ign system wiring diagram. I still think you have flooded the engine. The waste spark system relies on at least one clean plug per coil in order to work. If there is no path to ground through an ionized air gap, the spark will not happen. Keep in mind, the spark jumps from the ground electrode to the positive electrode on one plug and from positive to ground on the other plug. All waste spark systems are like this, whether it's a Honda, a Harley, or a Chevrolet. It may be hard to visualize, but that's how it works.
Not a clue on this one.
No aftermarket accessories like alarm or ignition switch fitted that may have disturbed the wiring?
(I had a similar problem with mine but luckily I had another to swap parts off to eliminate the fault, saves needlessly replacing parts too - know anyone local with a VN1500?)
Also try putting a post on the Kawasaki Vulcan forum, there's some knowledgeable guys on there, as on here.
Got the new VDS in, it changed the behavior of everything. The bike wouldn't spark at all with the kickstand down, etc as soon as I replaced the VDS. it would try to start before even with kickstand down and the clutch out.
Still have that spark issue. Clutch sensor works, neutral switch illuminates, kill switch works, fuel pump was working. Ignition switch working.
To reiterate, it will only spark ONCE when holding down the starter. If you keep holding down the starter button, it will not continue sparking.
Any ideas?
Quote from: 53Indian on April 07, 2025, 03:32:23 AMTry the basics first.
VDS sensor, as you say
Side stand switch wires OK?
Neutral switch illuminating?
Clutch switch, under lever, not disintegrated?
Engine kill switch, they look fine but fall apart inside housing
Fuel pump connection, does it sound with ignition on?
Ignition switch?
Starter relay/fuse?
Is the motor spinning if you jump the starter solenoid?
(ECU's rarely give problems)Process of elimination, you'll find it.
Yes,
I have already gone through that entire list. The motor will spin over via the starter motor, it just has the spark issue.
VDS has no continuity, so that's a problem in the first place. Should be here tonight or tomorrow and then we will find out.
Thanks for the suggestions!
Try the basics first.
VDS sensor, as you say
Side stand switch wires OK?
Neutral switch illuminating?
Clutch switch, under lever, not disintegrated?
Engine kill switch, they look fine but fall apart inside housing
Fuel pump connection, does it sound with ignition on?
Ignition switch?
Starter relay/fuse?
Is the motor spinning if you jump the starter solenoid?
(ECU's rarely give problems)
Process of elimination, you'll find it.
Vehicle down sensor.
It has no continuity, so I went ahead and ordered a used but allegedly operational one on ebay. It was also half apart when I found it so...
Update 2: Put VDS back together, no continuity in any situation. Bike will engage starter without it, but won't spark at all without it obviously.
Perhaps, this could be my issue?
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