Two crankshaft sensors

[andyvh1959]

The 1600 has two crankshaft sensors, one for each cylinder. It has two spark plugs per cylinder, and the ignition timing mark is F for the front cylinder and R for the rear cylinder. The 1600 is a 50 degree V-twin with both con-rods on one crankshaft journal. The 1600 has a timed spark for each cylinder, and the crankshaft sensor are spaced apart in the crankcase about 10 degrees. Makes me wonder if this is a designed ignition timing to give the 1600 a certain "vibe" or feel. It does have a sound "kind of" like a Harley but not quite as distinctive as a Harley.

A Harley, far as I know has only one trigger for the ignition to fire both cylinders on a wasted spark setup on the 45 degree v-twin. The wasted spark and shared con-rod crankshaft journal is one reason the Harley has that distinctive off-beat sound that everyone likes.

The VN1700 too has only one crankshaft sensor, firing only one spark plug per cylinder. Even though the 1700 is a 52 degree V-twin it too must have a wasted spark beat to it since the crankshaft sensor fires both coils, so it sounds a bit more "Harley" like.

So why do I ponder all this? Curious for one. But also I am trying to use the crankshaft sensors in the VN1600 to trigger a tach in the VN1700 gauge set i am mounting in the frame mounted fairing on my VN1600. So I am trying to figure out if it makes any difference which crankshaft sensor I use. It shouldn't since the crank triggers pass each sensor on every rotation, just one a bit later than the other. Anyone think Kawasaki uses the two crank sensors and two plugs per cylinder kind of like a MSD ignition where the extra plug per cylinder sparks a bit after the first plug?

[Kawi_addict]

I do not know but I wish someone who does would chime in

[Jllm02199]

It fires both plugs in the same cylinder from the same coil.
I would say you could pick up the tach signal at the coil input.
I haven't done it so I am guessing.

[Jllm02199]

Originally Posted by andyvh1959

The 1600 has two crankshaft sensors, one for each cylinder. It has two spark plugs per cylinder, and the ignition timing mark is F for the front cylinder and R for the rear cylinder. The 1600 is a 50 degree V-twin with both con-rods on one crankshaft journal. The 1600 has a timed spark for each cylinder, and the crankshaft sensor are spaced apart in the crankcase about 10 degrees. Makes me wonder if this is a designed ignition timing to give the 1600 a certain "vibe" or feel. It does have a sound "kind of" like a Harley but not quite as distinctive as a Harley.

A Harley, far as I know has only one trigger for the ignition to fire both cylinders on a wasted spark setup on the 45 degree v-twin. The wasted spark and shared con-rod crankshaft journal is one reason the Harley has that distinctive off-beat sound that everyone likes.

The VN1700 too has only one crankshaft sensor, firing only one spark plug per cylinder. Even though the 1700 is a 52 degree V-twin it too must have a wasted spark beat to it since the crankshaft sensor fires both coils, so it sounds a bit more "Harley" like.

So why do I ponder all this? Curious for one. But also I am trying to use the crankshaft sensors in the VN1600 to trigger a tach in the VN1700 gauge set i am mounting in the frame mounted fairing on my VN1600. So I am trying to figure out if it makes any difference which crankshaft sensor I use. It shouldn't since the crank triggers pass each sensor on every rotation, just one a bit later than the other. Anyone think Kawasaki uses the two crank sensors and two plugs per cylinder kind of like a MSD ignition where the extra plug per cylinder sparks a bit after the first plug?

Found this on the Kawasaki forum.


If Hot Cruiser's wiring is correct, then:

1. Red wire to coil terminal that has red/green wire attached.
2. Green wire to coil black or coil black/green terminal, depending on which coil you attach to.
3. Black to ground. Can use black/yellow in headlight bucket.
4. Yes, you can just prop tank up to access coils.
5. No adapter required IF tach is set up for dual fire in the first place.

[andyvh1959]

Thanks, But those are all to connect an aftermarket tach using an inductive coil pickup as the speed signal to the tach. My Classic already has an aftermarket Baron tach.

What Kawi_Addict and I are trying to do is use the VN1700 gauge set (from either a Voyager or Vaquero) which has the speedo/odo and tach in a gauge cluster. Got the speedo/odo figured out. But the tach on the VN1700 gets a CANBUS signal from the ECM on the 1700. We could just add a VN1700 ECM to the install, but those are not cheap ($350+ on ebay) and where then to mount another ECM.

I just shipped my 1700 gauge set to Mark Olson at Accutach in San Jose CA. Mark will modify the circuit board to isolate it from the CANBUS feature so I can signal the tach from one of the crankshaft sensors on the VN1600. Mark is the only person (of five) I contacted to tackle this setup. Mark could turn out to be a good source for electronic works on our Vulcans.

[Kawi_addict]

Originally Posted by andyvh1959

Thanks, But those are all to connect an aftermarket tach using an inductive coil pickup as the speed signal to the tach. My Classic already has an aftermarket Baron tach.

What Kawi_Addict and I are trying to do is use the VN1700 gauge set (from either a Voyager or Vaquero) which has the speedo/odo and tach in a gauge cluster. Got the speedo/odo figured out. But the tach on the VN1700 gets a CANBUS signal from the ECM on the 1700. We could just add a VN1700 ECM to the install, but those are not cheap ($350+ on ebay) and where then to mount another ECM.

I just shipped my 1700 gauge set to Mark Olson at Accutach in San Jose CA. Mark will modify the circuit board to isolate it from the CANBUS feature so I can signal the tach from one of the crankshaft sensors on the VN1600. Mark is the only person (of five) I contacted to tackle this setup. Mark could turn out to be a good source for electronic works on our Vulcans.

The home work and personal time you have put into this project is mind blowing! Wish I could dedicate enough time to just get in the shop once a week....

[andyvh1959]

Originally Posted by Jllm02199

It fires both plugs in the same cylinder from the same coil. I would say you could pick up the tach signal at the coil input.
I haven't done it so I am guessing.

Yup, fully understand.

I'm just trying to understand why Kawwy decided to use two crankshaft sensor triggers coils, one for each cylinder, but about 10 degrees apart. In the Kawwy factory manual for the VN1600 it even specifies to check ignition timing for each cylinder by using the respective ignition trigger, and each cylinder has a separate timing mark on the flywheel.

The dual plugs per cylinder have nothing to do with it, because one ignition trigger is sufficient to signal multiple plugs to fire. By comparison, the VN1700 has only one crankshaft sensor trigger coil. Both the VN1600 and the VN1700 are near equal v-twins, the VN1600 is a 50 degree v-twin, the VN1700 is a 52 degree v-twin. Both have a shared crankpin journal for both pistons, means the double ignition triggers has some other function on the VN1600. Dragon Lady58 or MAStequila any ideas?

[Kawi_addict]

@dragonLady share your secrets! Lol

[DragonLady58]

[andyvh1959]

The only reason I can fathom why there are two ignition triggers, one for each cylinder is:
1. Better performance? The 2nd cylinder is timed about ten degrees after the 1st cylinder. Each cylinder is timed individually for the best spark timing.
2. Better ignition? No wasted spark when a dual fire (both cylinders fire together) ignition is used. But you don't get the extra quieter "thump" of the spark firing during the mid exhaust stroke of the 2nd cylinder.

So I did a net search of "v-twins with twin ignition" and found a bunch of references to improve Harley performance by changing the "dual fire" ignition (both cylinders fire at the same time) to a "single fire" ignition where each cylinder fires individually at the most optimal timing. Perhaps Kawasaki was ahead of the game to do a single fire ignition on the VN1600 versus the Harley norm of dual fire ignition? Also the VN1600 has two plugs per cylinder, better combustion, better power.

Which then it really puzzles me that on the VN1700, Kawasaki went to a dual fire ignition, both cylinders fire at the same time, with no timing adjustment for either cylinder to optimize ignition timing. Sure the 1700 makes power, more torque, but perhaps that is also how the engine is tuned versus the 1600. With some mods the 1600 can make near the power of the 1700.