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Discussion Starter #1
Hi, I'm replacing the front pickup coil with this one here:

https://www.regulatorrectifier.com/catalog/1986-2006-kawasaki-vn750-vn-750-pickup-coil

Now this coil has a teal wire and a green wire. The OEM coil has a black wire and a black/yellow wire. I'm planning on splicing the new wires into the existing ones behind the cover as to not need to remove the engine.

Which wire would goes to which? Or does it not matter? Thanks.
 

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Think I would try to match it up by the wire position on the stock p/u coil. Trace the original top/bottom wires back to where they connect, then run the top/bottom wires on the new coil to the locations matching the original.

All black/yellow wires on this bike are grounds, but this particular black/yellow could go directly to the CDI.

You might be able to ohm test for continuity between the wires on the new coil and it's mounting plate. It's not foolproof, but if only one wire has continuity to the frame of the coil, there's your black/yellow connection.

Great time to do the pickup coil mod!
 

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Discussion Starter #3
Think I would try to match it up by the wire position on the stock p/u coil. Trace the original top/bottom wires back to where they connect, then run the top/bottom wires on the new coil to the locations matching the original.

All black/yellow wires on this bike are grounds, but this particular black/yellow could go directly to the CDI.

You might be able to ohm test for continuity between the wires on the new coil and it's mounting plate. It's not foolproof, but if only one wire has continuity to the frame of the coil, there's your black/yellow connection.

Great time to do the pickup coil mod!
Thanks, I'll try that when it arrives.

And for the mod, what exactly is the .20" gap being set against? I've read the threads about it but I still don't understand what It's being measured from.

Thanks!
 

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Thanks, I'll try that when it arrives.

And for the mod, what exactly is the .20" gap being set against? I've read the threads about it but I still don't understand what It's being measured from.

Thanks!
It's the gap between the face of the p/u coil and the magnet on the rotor.
 

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Discussion Starter #5
It's the gap between the face of the p/u coil and the magnet on the rotor.
Is it possible to check if a wire is good with a multimeter? I ask because after installing the new p/u coil, the signal wire to the ignition coil gets a reading of 23v on my automatic multimeter (battery attached), which is the same as the real ignition coil signal wire, yet the front plugs still don't get spark. Both ignition coils read 1.9 ohms, which is in spec. the 4 pin connector on the ignitor all checks out, but I can't seem to properly test the 6 pin (where the signal wires come from). Could this be a wiring failure or an ignitor failure? or does that measurement on the wire even mean anything? has a ghost possessed my bike?

Thanks.
 

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Is it possible to check if a wire is good with a multimeter? I ask because after installing the new p/u coil, the signal wire to the ignition coil gets a reading of 23v on my automatic multimeter (battery attached), which is the same as the real ignition coil signal wire, yet the front plugs still don't get spark. Both ignition coils read 1.9 ohms, which is in spec. the 4 pin connector on the ignitor all checks out, but I can't seem to properly test the 6 pin (where the signal wires come from). Could this be a wiring failure or an ignitor failure? or does that measurement on the wire even mean anything? has a ghost possessed my bike?

Thanks.
Absolutely the wire can be tested. On a basic meter just use the ohm setting, more advanced meters will have a specific continuity setting, some with an audible test, beeps if there's continuity.

23v huh? Typo .. 13v? What setting are you using on the meter?

I don't believe the CDI/Ignitor can boost voltage, but I'm pretty sure there are tests for it in the manual listed in my signature. There are also ohm tests for the p/u coil. That 6-pin on the Ignitor might involve a diode test, not sure.

I'm not sure there should be voltage on a pickup coil, it's a hall effect sensor if I'm not mistaken, uses the magnetic field on the rotor to trigger the spark at the correct time.

Which color wire are you referring to as the signal wire at the (front) ign coil? I'll try to look at the wiring diagram. Maybe the wires are crossed up?
 

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A lot of what you said didn't make sense to me. Granted, the ignition system is sort of at the border of my understanding, so maybe I'm mixed up about some things...

What are you touching your leads to when you are reading 23v? Is the bike running (or cranking) when you do this?

I *think* that the CDI provides a signal by switching the dark green (pin 1) and black (pin 4) wires to ground voltage in order to interrupt current from the red wire through the primary winding of the ignition coil, inducing spark via the secondary winding.

As far as I know there shouldn't be 23v anywhere? the green and black wires from the CDI to the ignition coils should be measurable as having 0 ohm on a multimeter.
I also think both spark plugs need to be grounded in order to get either one to spark, so if you're looking for spark by holding just one against the chassis while leaving the other dangling, you'll get no spark. I *think*.
 

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Discussion Starter #8 (Edited)
Absolutely the wire can be tested. On a basic meter just use the ohm setting, more advanced meters will have a specific continuity setting, some with an audible test, beeps if there's continuity.

23v huh? Typo .. 13v? What setting are you using on the meter?

I don't believe the CDI/Ignitor can boost voltage, but I'm pretty sure there are tests for it in the manual listed in my signature. There are also ohm tests for the p/u coil. That 6-pin on the Ignitor might involve a diode test, not sure.

I'm not sure there should be voltage on a pickup coil, it's a hall effect sensor if I'm not mistaken, uses the magnetic field on the rotor to trigger the spark at the correct time.

Which color wire are you referring to as the signal wire at the (front) ign coil? I'll try to look at the wiring diagram. Maybe the wires are crossed up?
I have a really bad "automatic" $10 autozone multimeter, so it chooses the range for volts. All i know is the black signal wire from pin #4 on the cdi reads "23" on DC current when the positive end is touching the terminal on that wire and the negative is on ground. For ohm testing, should I measure the wire against ground? I'm definitely leaning towards a crossed wire somewhere in the harness. The bike was not cranking during the measurements, but it was connected to the battery.
As far as ohms go, the coil tested good.

The ohm readings on the 4 pin all tested in spec, my multimeter does not display infinity (it just goes to 0) so I can't really guarantee that the 6 pin is in spec. If I can't fix this with a new jumper I will assume bad CDI.
 

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Your multimeter should read '0' for a short, and 'OL' for a break/no connection. If it doesn't make that distinction, it's absolutely worthless.

To measure the ohms of a wire, connect one lead to each end of the wire. Putting a lead on ground tells you nothing (unless ground is one end of the wire).

I really can't think of any reason 23v would show up there. Was the ignition switch 'on' and the kill switch 'on'?
 

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Not sure we can trust that meter, reading 23v on the DC setting, I've tossed a few cheap meters. About $25-28 will get a decent one at Lowe's. There's just not that much voltage available. When you said it reads "23" in your last post, I thought maybe it was auto-switching to ohms, but you said it's on the DC setting.

You may be right about the CDI, maybe that's why someone tried to rob signal from the rear coil.

Did the tach work? Black wire off the 4-pin also runs to the tach. All terminals on the 4-pin (cdi) need to read 4-6 ohms.

Need to test the 6-pin @ the cdi too, and there's a wide range of ohm readings shown on the chart in the manual. Infinity, 0.9 to 1.7 ohm, 2 to 4 ohm, 3.6 to 6 ohm, 14 to 26 ohm, and 25 to 50 ohm, depending on the combination of terminals being tested.

If you're testing for continuity on the black wire, you should disconnect the 4-pin cdi plug, make sure the kill switch is set to run, then check between the 4-pin black and the end at the ignition coil.
 

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Discussion Starter #11
Not sure we can trust that meter, reading 23v on the DC setting, I've tossed a few cheap meters. About $25-28 will get a decent one at Lowe's. There's just not that much voltage available. When you said it reads "23" in your last post, I thought maybe it was auto-switching to ohms, but you said it's on the DC setting.

You may be right about the CDI, maybe that's why someone tried to rob signal from the rear coil.

Did the tach work? Black wire off the 4-pin also runs to the tach. All terminals on the 4-pin (cdi) need to read 4-6 ohms.

Need to test the 6-pin @ the cdi too, and there's a wide range of ohm readings shown on the chart in the manual. Infinity, 0.9 to 1.7 ohm, 2 to 4 ohm, 3.6 to 6 ohm, 14 to 26 ohm, and 25 to 50 ohm, depending on the combination of terminals being tested.

If you're testing for continuity on the black wire, you should disconnect the 4-pin cdi plug, make sure the kill switch is set to run, then check between the 4-pin black and the end at the ignition coil.
Just to be super clear: you mean the cdi plug with pin #4, not the cdi plug with 4 pins, right? the pins on the 4 pin connection all have 4.1 - 4.3 ohms so that's good, the 6 pin is the one that reads "0" on the ones that should say infinity. (I wasn't sure if it can even display "infinity" though, as the pin for the working ignition coil also reads 0 instead of infinity)

And the tach sort of worked? it jumped around, jiggled a lot, and never read above 1500 even after revving it up.

But yeah, i'm 99% sure this multimeter is junk. I'll retry the wires/cdi box tonight with a better meter, and if the resistance is good I'll just splice in a new wire a few inches off the box for pin 4 straight to the coil. If that doesn't work, then it's time for a new CDI.

To rewire the tach, I'd assume I need to take the headlight off, but I can't figure out how exactly. Is there a special way to do it? the side bolts just keep spinning past a certain point.

Thanks a lot, you guys are very very helpful
 

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Just to be super clear: you mean the cdi plug with pin #4, not the cdi plug with 4 pins, right?
No, I was referring to the cdi plug terminal with four pins. Those should all be 4-6 ohms, terminals 7, 8, 9, 10, all measured between each other.

Pin #4 (at the 6-pin terminal) should be infinite between all other terminals on the 6-pin on cdi. Pin #4 should show no connection at all to any terminal of the 4-pin outlet.

All the rest on the 6-pin outlet are the varied ohm readings from the chart. 0.9 to 50 ohms

I'm leaning toward the CDi myself, but it could still be the black wire. Your tach was probably jumping around initially because of the signal supplied from that jumper wire off the rear coil. This jumper has been disconnected now, correct?
 

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Discussion Starter #13
No, I was referring to the cdi plug terminal with four pins. Those should all be 4-6 ohms, terminals 7, 8, 9, 10, all measured between each other.

Pin #4 (at the 6-pin terminal) should be infinite between all other terminals on the 6-pin on cdi. Pin #4 should show no connection at all to any terminal of the 4-pin outlet.

All the rest on the 6-pin outlet are the varied ohm readings from the chart. 0.9 to 50 ohms

I'm leaning toward the CDi myself, but it could still be the black wire. Your tach was probably jumping around initially because of the signal supplied from that jumper wire off the rear coil. This jumper has been disconnected now, correct?
Yes, the jumper is disconnected now.
 

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Yes, the jumper is disconnected now.
Ok good, and the tach is still erratic, correct?

If so, then it seems the trigger signal is erratic, inconsistent, from either the CDI, p/u coil for the front cyl., or a wiring problem.
 

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Discussion Starter #15
Ok good, and the tach is still erratic, correct?

If so, then it seems the trigger signal is erratic, inconsistent, from either the CDI, p/u coil for the front cyl., or a wiring problem.
Yep, time to diagnose! I found a CDI for $50 on ebay so worst case scenario I won't be shelling out too much.
 

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If you still need a multi-meter I figure the auto parts stores should have one in their loaner program. Always best to test.

Problem could possibly be in the p/u coil circuit.
 

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Discussion Starter #17
If you still need a multi-meter I figure the auto parts stores should have one in their loaner program. Always best to test.

Problem could possibly be in the p/u coil circuit.
Fixed it!

Ran a higher gauge wire right off pin #4 to a smaller spade terminal to the front ignition coil and it worked perfectly. So that's the biggest problem out of way.

Now I need to rewire the tach, do you know how to access where the wiring to it is? I ask because there are 2 black wires going into the headlight assembly and I don't want to guess on which is which.

Thanks!
 

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Great!

There's only one black wire at the tach, so you'll have to get in there. I welded the tach bracket, and that's as far as I've been. Three wires total on the tach.
 
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