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Message started by mjs3790225 on 08/17/13 at 10:47:25

Title: Voltage off the signal generator / pulse generator
Post by mjs3790225 on 08/17/13 at 10:47:25

Hey all, I've been trying to work my way through a no spark problem lately. I was wondering if anyone knows what the voltage coming off that signal generator thing inside the stator cover is supposed to be putting out.

I've already given it the ohms test, and it checks out fine at around 240ohms. But I don't know if it is actually putting out a voltage when cranking the engine over. I can't get a reading off it with my digital multimeter. I'm gonna dig through my box of electro crap and find an analog volt meter, but I still would like to know if it is a measurable thing.

Other things I've tested:
- Coil ohms on hookup end and spark plug end were good. (switched it for good measure)
- Ground from case to battery good.
- Switched spark plugs
- Voltage on battery good.
- Switched the ignition control box. (my bike is a '96 and I switched with a '09)
- Starter cranks great.
- pulled out battery box and checked the wire loom that runs past the drive belt. No damage.
- lights turn on

My bike died while slowing down for a stop light and never started back up again. Pulled the plug out looking for spark and never saw a thing. Sure put an end to my midnight cruise! Haha! ::)

I probably have somewhere between 23k - 27k miles on it. It doesn't keep track correctly anymore.

Title: Re: Voltage off the signal generator / pulse gener
Post by mjs3790225 on 08/17/13 at 13:41:06

So I've been doing some science with an extra signal gen pickup coil thing.

Using a magnet in hand, and waving it back and forth as fast as I can over the magnet on the coil, I've been able to generate almost 2 volts AC. I don't know how much they normal generate, but I'm going to guess a real motor is much more.

I've also checked the milliamps out of it and gotten about 10ma AC. Again, real motor action will prob be more.

On an interesting side note, while doing so, resistance drops to zero across the pickup. Probably has something to do with a magnetic field collapsing. I'm no electrical engineer though =P

Gonna run some tests on my bike now.

Title: Re: Voltage off the signal generator / pulse gener
Post by justin_o_guy2 on 08/17/13 at 14:50:12

Well, I have an associates in electronics & youre way past me,, I didnt get most of your post, but, sounds like youll hunt it down if anyone would..

Title: Re: Voltage off the signal generator / pulse gener
Post by mjs3790225 on 08/17/13 at 15:42:09

Yep! Still plugging away at it!

So the latest news on the situation is this:

I can manually generate a spark by grounding the spark plug coil. Like, no problem at all. So that is awesome news to finally see a spark. Regardless, doesn't solve the problem.

During normal cranking, I was actually able to see one spark this time. Just at the beginning, and then no more. Again, not helpful.

What could be helpful is this:

I tested the voltage coming off the pickup coil and got about .5 volts AC tops during the cranking process. If I can generate 2 volts waving a magnet back and forth with my hand, I'm guessing this is problem. As for the current coming off the pickup, it was pretty much non existent. Barely a milliamp.

Start theory.

My current theory is that the ignition control box needs to receive a signal to saturate some sort of transistor to tell it to dump the voltage off the coil and make a spark. And that with .5 volts, it is not getting a strong enough signal.

However, since I was able to get a single spark for the first crank instance, I must be fairly close to that saturation point.

My next step is this:

Take my signal generator pickup coil thing that I've been playing with the magnet with, and hook it to where the normal connection points for the pickup on the ignition control box are. From there, wave my magnet back and forth and see if I can fire a spark off manually that way.

If that works, (for one it verifies I'm not using a sucky ignition control box because I can tell it to fire a spark whenever I want), its got to be something going on with my rotor. Either the signal generator thing is too far away, or my magnetic portion is too weak.

End theory.

Title: Re: Voltage off the signal generator / pulse gener
Post by justin_o_guy2 on 08/17/13 at 15:46:57

Im trusting youve done the Eyeball on every connection in the circuit,, If so & all looks good, then trace Voltages,, You have a wiring diagram, you know where it sposed to be 12 volts. PROVE, with an ohm meter, the main ground on the engine,
How are the lites acting? Horn? Starter speed? Sounds/looks like the battery power is all there?

Title: Re: Voltage off the signal generator / pulse gener
Post by mjs3790225 on 08/17/13 at 15:57:32

I think I've been eyeball'n them wires pretty good. I've done tracing with my meter on a lot of them. I can tell for certain I am getting a nice 12v to the orange wire on the control box. And a nice 12v to the coil. Close to zero ohms along the ground wire from the coil to the ignition control box. Ground to the control box seems good too. All seem to be close to zero ohms. There may be a few wires I've missed, but I think I hit all the important ones. I'm still leaning towards a signal generator related issue.

All lights work great, horn I have on a separate circuit so that is out of the equation. Battery I just took off the charger and had good voltage. It is a nice AGM that I bought earlier this year. Crank speed seems pretty normal as far as I can tell. I've done most of the cranking without a plug in the hole, so it definitely doesn't have to try either though.

Biggest help to me right now would be if somebody could measure the AC voltage coming off their pickup coil wires that lead into the ignition control box. That way I can do a little cross referencing. :-?

Title: Re: Voltage off the signal generator / pulse gener
Post by mjs3790225 on 08/17/13 at 16:01:15

I can't recall if I checked my engine ground. I think I did. Almost positive..... or is that negative ;D I'll double check it again tomorrow to make sure. Its broken down across town, so I have to keep driving my car over to it when I have time to work on it. Sucks when you forget that ONE tool. :o

Title: Re: Voltage off the signal generator / pulse gener
Post by justin_o_guy2 on 08/17/13 at 16:29:30

Man,, You need that thing Home... bummer..

Title: Re: Voltage off the signal generator / pulse gener
Post by Steve H on 08/17/13 at 17:36:45

If it was around here, somebody would have carted it off, cut it up, and sold it as scrap metal by now. Rent a U-haul trailer and get it home before something happens to it.

Clymer says check the resistance between the two wires from the pulse generator. If it's between 200 and 240, you're good. Otherwise replace. They make no mention of voltage, cranking or otherwise from it. It does say that the pickup is part of the stator assembly and you'll have to replace the stator if it's bad.

Hope that's of some help to you. I'm afraid the book doesn't really say that much about the ignition system.

Hope you get it figured out soon.

Title: Re: Voltage off the signal generator / pulse gener
Post by mjs3790225 on 08/18/13 at 11:12:38

Gosh, that would be the worst day ever; going back to the bike and not finding a bike. Lucky for me, I was able to get it pushed to a nearby friend's home. Not the best neighborhood, but I'm not super concerned about it. Still going to borrow a trailer and get it home though.

Pickup coil does checkout with correct ohms.

In other news, EXCITING developments!

I am now getting spark through normal cranking operation.

Previously, when this all first started happening, my first attempt at fixing it was to replace the pickup coil. I know the manual say not to do this and to replace it with the stator and everything. I think the only reason they say this is because they don't want people splicing wires inside the case or breaking that special rubber grommet forcing new wires through and creating an oil leak.

Which is really wise advice: high temperatures would most likely melt standard heatshrink wrap, and pity to the person who decides to wrap his solder joints with electrical tape. All that turbulent oil flipping around everywhere would probably cause all sorts of problems. Needless to say, I am using a special self sealing splice tape that fuses together and is good up to 500 degrees. I trust I will be fine patching in a new pickup coil. Though, come to think of it, oh crap, I should double check the melting point of my solder :-/ Actually, this will probably end badly. I must revise my connection. Anyway, I will attend to that later.

Anyway...

Unfortunately for me, the new pickup coil had no wiring diagram and apparently, I matched the wrong wires and reversed the polarity. I have since reversed them and can fire off sparks no problem while cranking.

But wait, does this mean problem solved? In all actuality, I have no idea what went wrong, because my old pickup coil still tests out correctly. My old ignition control box seems to function correctly too. And when I throw my old spark plug coil back on, I think that is going to fire just as well just the same (again, all these things TESTED fine to begin with). Will follow up on that soon.

So it looks like in this project, I have introduced a lot of variables; which doesn't really go well with good science. The only one to remain the same will be the new pickup coil. Still seems like an odd change when the other registers fine.

BUT, through all this experimenting, I believe I have found an easy, new viable way of testing the ignition control box for correct operation. I will do a write up on this later. I owe all the experimenting with an off board pickup coil and magnets to this discovery. And as it turns out, that half volt I'm getting seems to be fine for the ignition control box to fire off a signal. Really, since the ignition control box is transistor controlled, a high voltage isn't really needed on the trigger end. Transistors are current controlled. And though I seem to be getting less than a milliamp of current on startup, it may be more than enough to create the needed gain and amplification to carry down the rest of the line into a voltage that actually matters. Cool stuff.

In conclusion, if all that WAS wrong turns out to be the old pickup coil, maybe the magnet that is in the pickup is wearing low on power, and the air space between the pickup and the rotor was finally too much to make it work properly. I have no idea for certain, but any idea sounds better than no idea.

Testing method with pictures and junk pending! (and me fixing my poor pickup swap :-[ )

Science! :D

Title: Re: Voltage off the signal generator / pulse gener
Post by gizzo on 08/18/13 at 16:38:14

Nice work, man. Well thought out ideas and tests and well written, too. Thanks.

Title: Re: Voltage off the signal generator / pulse gener
Post by justin_o_guy2 on 08/18/13 at 18:10:23

I cant count the copiers & cash registers & calculators Ive"Fixed" & had no idea what I did,, Just the process of opening it up, taking things out, putting them back & shazzam! They work,, sometimes, anyway,,Of course sometimes thers a real problem & ya just gotta fix it,, & then sometimes, ya wanna fix it, but, it wont fix,,