'82 450 Igniter - Repair, Replace, or Make?

[john82q]

Pete,
This morning I went to measure this too, but the 1100 must be different as seems to have 4 wires from the pickup, and i wasnt sure which was which and didnt have time.

Anyway I grabed the green wire and got 20mv peak to peak. cranking with the starter.


dont see the scope taking a weekend to organise I could drop it off one evening.

john

[pete]

Cheers for that John, the 450 has four wires on the pickups, but one is common to both so there are only three going off to the harness.

Evenings aren't real easy for me as my wife normally goes to bed real early, but I'm sure something can be organised if we need to do that.

Cheers again for the offer too!

[john82q]

could'nt have been more wrong

Previous post was wrong. (wrong wires)

actually its more like 3 V peak to peak, looks like this.


this is one coil, the 1.5v drop should trigger the HEI no worries.


John

[pete]

Previous post was wrong. (wrong wires)

actually its more like 3 V peak to peak, looks like this.


this is one coil, the 1.5v drop should trigger the HEI no worries.


John

Cheers John! You've just confirmed what I just witnessed for myself in the garage (except not with a scope), although I'm still a little confused.

I decided to ditch all my previous attempts and information and what not and just see what happened if I hooked it up exactly like what is shown on the website for the modules in use with a distributor, which also is the same way the Honda CX650 hook up was done initially.

This link is what I got that CX650 info from:

http://webpages.charter.net/n8nxf/HEI-CX650C.pdf

So, only one module hooking up temporarily again tonight, I put the brown wire from the right pickup coil onto the W connector, the black/white common for both pickup coils onto the G connector, grounded the heatsink/mounting hole, +12V to B, and black/yellow for the right ignition coil to C.

I then spun the crank and got some good looking sparks!

My only confusion now is that my understanding is that it should be a wasted spark situation, meaning a spark every full revolution of the crank.

However, I'm only getting a spark every second revolution.

I'm hoping this is somehow due to me only having one module and pickup coil connected, but does anyone have any other thoughts on why this would be?

I didn't get down til late tonight and I'm a bit on the tired side so I didn't hook the second module up to see if that changed that behaviour or not, but hopefully I'll be able to do that tomorrow night.

My concern at the moment is that sparking with me spinning the crank is one thing, but once the motors running and spinning up to a real RPM, will I start encountering issues like the guy with the CX650 had or like Lou found with the KZ and Hondas?

The one big difference I can see between the KZ and Honda CB is that the pickup coil resistance is much higher on those (200 or 300 ohms from memory) whereas the 450's are 60 to 80 ohms. Not sure about the CX650 pickup coils.

So, in a nutshell, some limited success tonight... starting to definitely get some satisfaction here

[rustybronco]

My only confusion now is that my understanding is that it should be a wasted spark situation, meaning a spark every full revolution of the crank.

However, I'm only getting a spark every second revolution.

Pete, while it may have been a wasted spark system from the factory, by having two coils and two cylinders I don't see why you would need a wasted spark system. firing once every other revolution should work just fine.

[Nessism]

Pete, while it may have been a wasted spark system from the factory, by having two coils and two cylinders I don't see why you would need a wasted spark system. firing once every other revolution should work just fine.

Pete's right Dale, the system should spark with each crank revolution. If it's not, something is wrong.

[rustybronco]

Ed, I don't know a thing about 450's. are there two pickup coils used, or just one?

[mike_of_bbg]

The fiche shows two - which makes sense with two coils - but for the life of me I have no idea why. I'd think with a twin the cylinders should be firing 360 degrees from each other in crank rotation.

But hey, what do I know?

[Matchless]

Pete, you should get a spark every time the metal stub on the crank passes the pickup coil.

Once you have a spark the main issue is to get the dwell within limits thus making sure that the spark stays good at higher RPM's as well.
If the dwell is too short the coil does not get enough time to build up a good magnetic field especially at higher RPM's, thus weak or no spark at high RPM's. It is basically determined by the width of the pulse, but using the HEI with a pickup for which it was not designed the HEI may, for example, only be triggered near the peak of the pulse and thus getting too short a pulse to properly activate the coil. That is where the biasing comes in.
I stand corrected, but if the dwell is too long the coil does not get enough time to fully "discharge" when the magnetic field collapses before it is triggered again. Again mostly at high RPM's I would think.

It seems as if you are on the right track and may just need to up the biasing voltage carefully from zero until you have a good dwell reading at lower AND high RPM.

Good luck!

[rustybronco]

Andre, would the negative going side of the sine wave have anything to do with it firing every other revolution? what would happen if one included diodes to use only each half of the wave form per pickup coil. do you think the forward voltage drop from the diodes being in circuit would provide too little signal for the HEI module?

skool me...

[pete]

Thanks for all the replies guys, and thanks for making my head stop hurting Ed!

Firstly, as far as the pickup coils go, there are two coils. The governor on the end of the crank has what looks to be a magnet embedded in one side of it, meaning that to my mind every 360 degree revolution should give a spark, with left and right offset by 180 degrees.

Andre, what you say makes sense and I have tried to digest a lot of what Lou has said in his HEI notes also, but I need to read them some more yet.

So far though, whenever I have tried to introduce any bias whatsoever, it has not produced any spark at all, which is why I reverted to the most basic setup.

I'm wondering though if turning the crank by hand is not fast enough to really simulate what I need to test it properly.

[Matchless]

Andre, would the negative going side of the sine wave have anything to do with it firing every other revolution? what would happen if one included diodes to use only each half of the wave form per pickup coil. do you think the forward voltage drop from the diodes being in circuit would provide too little signal for the HEI module?

skool me...

Dale,
I do not know exactly how the HEI module functions, but would assume it only responds to either the negative or positive part of the waveform, which it receives every time the pickup is actuated. I briefly looked at it about 2 years ago and did not bother much once I got it working. Here is an extract of a note Lou sent me at the time. He has a very extensive summary here on his website, which may shed some light on the issue: http://home.comcast.net/~loudgpz/GPZweb/index.html#home

The HEI module is not just plug and play and needs some different modifications for various bikes to enable the pulse from the bikes pickups to properly trigger the module and he has investigated various methods. Worst case scenario one may need to use his transistor driver that he uses for the points type approach near the end of his write up driven by the pickup coil.

HEI Module:
To describe this project, some background should be given about the HEI module. The module has 4 terminals plus a heat sink with mounting holes.

The heat sink and mounting holes are the ground for the module.

Terminal “B” is the power connection for the module.

Terminal “C” is the output for the module. It completes the ground path for the ignition coil. Interrupting the ground path causes the coil to generate a spark.

Terminal “G” is the input to the module. When the voltage at G is higher than about 1.6 volts, the C terminal is grounded which completes the ignition coil’s ground path. When the voltage at G is lower than about 1.4 volts, terminal C is open. When C first opens, the ignition coil produces a spark.

An HEI module is designed to be controlled by an inductive pickup. Terminal “W” provides a control voltage to the pickup. This control voltage extends the dwell to the ignition coil during high-rpm operation. The control voltage will not be used in this project. The dwell-control voltage is overridden by connecting W to the supply voltage.

However, the W terminal is used for another purpose in the time-out option of this project. The purpose of the “time-out” option is to prevent the ignition coil from overheating when the ignition switch is turned “on” with the points closed but with the engine not running. It works by switching off the ignition coil after 5 seconds.

[pete]

Andre, they look like different notes as to all the ones on his site, although I can't promise I've looked at everything yet (feels like I have several times though).

Were those notes ones he did specifically did for your 1000? If so, is there any chance you could shoot them through to me or are they on your Mediafire page? I don't recall seeing them there but I'll go looking now...

[rustybronco]

Andre, I got it. thanks!
(http://home.comcast.net/~loudgpz/GPZ...itionNotes.txt)

[pete]

That's the ones Dale (yay finally worked out who Dale is... ).

I've read through them a few times and have printed them out so I can read more, and in fact I'll be doing that again on the train in to work today because I know I'm getting close, but something's just not quite right.