How much voltage should a 6v stator put out?

[Helve]

Curious to see what kind of voltage a 6v stator should be putting out when the bike is being kicked over. Manual says it should be ~40v at 4k RPM, but as the bike isn't running I'm not sure what kind of voltage I should be seeing. Getting 4.5-6v per kick, generally. Thoughts?

 

[mydlyfkryzis]

At kick over it isn't going to put out much....For instance, a CB360 (12V, but the process is the same) puts out max capacity at 9000 RPM, but is rated at 5000 RPM at 130 watts....At idle, it doesn't put out enough maintain 12V. At kick speeds, it is even less.

So 6V is O.K. at kick on a 6 volt system. The 40V @ 4000 RPM is likely the AC side....After going through a rectifier, the voltage will/should be in the 6.5 to 7.5 volt range.

Even if the lighting is 6V ac, 40 V AC would kill the bulbs.

I believe your bike is CDI, is this about the lighting coils or the CDI coils?

 

[Helve]

Yes, that's the AC side.

No CDI on this bike, it's points. I'm at a loss to why I'm not getting spark. Checked the coil, checked the wiring, checked the points and timing, checked the kill switch and ignition key, new plug, new coil, new plug cap/resistor. I want to throw in the towel. I'm losing signal somewhere, obviously, but I think I may be in a bit over my head at this point. Somehow I'm still not getting any spark.

 

[VonYinzer]

Did you check the plug wire? Is it original? If it's replaceable, do so. Seems stupid but sometimes it's the little things.

 

[SONICJK]

Did you check the plug wire? Is it original? If it's replaceable, do so. Seems stupid but sometimes it's the little things.

This.
If not replaceable pull the boot off and cut 1/2 or so off the wire and put the boot back on.

 

[Helve]

Plug wire is hard wired to the new coil, so yes it is new.

 

[mydlyfkryzis]

4Are you getting 6V to the coil? If there is no power to the coil, no sparky....Electric trouble shooting works best by being methodical.

Does theis bike have a battery? is the battery charged?

 

[Helve]

Battery, yes and yes.

I haven't tested if the coil is getting spark, actually. I sort of figured that since I was getting signal at the 4pin connecter that leads to the points/coil that the signal would be getting to the coil. There is only one 4 way connecter (signal from magneto, power to points/condenser and the coil) which could be the issue, I should probably test there to find out. Unless the wire itself is bad, I'm pretty sure that's the only junction between the magneto and the coil.

 

[Helve]

Signal is making it to the coil, checked tonight. Coil is well within range testing the primary and secondary windings. Without the boot, still no spark from the spark plug wire when grounded against the engine/exhaust. Spent about 4 hours with a buddy trying to figure out where the problem is coming from, he was just as baffled as I am. I feel like I've checked every connection from the stator to the coil and somehow everything seems fine yet there is still no spark!

 

[mydlyfkryzis]

If you put 6V on the coil, then remove it, the coil should spark. If not, check grounds and wires....When the points are open, you should see 6V to ground at the points (The open arm, not the grounded side).

If you put 6 Volts to the coil, remove, and get a spark, then the problem is further down the road....That would either be wiring or points. If you have voltage to the coil, to the points, then opening and closing the points (manually) should give a spark.

If not, then the high voltage side has an issue or the coil has an internal voltage leak on the high voltage side. An internal crack could cause the spark to leak to ground, but not be seen with a voltmeter test.

 

[mydlyfkryzis]

Here's a diagram on the coil test procedure....

 

[teazer]

Couple of thoughts:

Is it magneto ignition or battery? Have you checked the kill switch isn't shorted out? Is the motor grounded to the frame effectively?

 

[Helve]

Magneto, yes I checked the killswitch and the ignition key wiring, everything is grounded as it should be.

 

[mydlyfkryzis]

Then ignore the coil test A magneto does not use the battery to excite the ignition coil.




Sent from planet Earth using mysterious electronic devices and Tapatalk

 

[teazer]

Do you have a wiring diagram or link to one and how close is the timing to what the manual says it should be? A points magneto is a thing of wonder - you always wonder if it will work.... Timing is usually critical because it has to coincide with the point of maximum flux in the flux capacitor - I mean from the charge coil. If the timing is off, sometimes the spark is too weak to fire anything.

Are you trying to see the spark in a spark plug or did you take out the plug and use a spark tester from your local auto parts store? The latter is easier to see a spark, but still not much of one at kickover.

Do you have a way to push the bike in gear and watch for a spark at the same time - get a buddy to push - it's easier. It may be that the magnets are weak and it needs to spin faster to generate enough power to jump the gap. Another possibility is a dead (shorted) capacitor. I had that problem on my first bike with a flywheel magneto and when the capacitor died the sparks died too. Try a new capacitor and see if that makes your day.

 

[Helve]

I thought about it being the capacitor, actually. Problem is, the only replacement I can find are $30-40 or have to be bought in packs of 1000. Would hate to drop that kind of money just to find out it wasn't the issue. Kinda sucks having a bike that no one makes aftermarket parts for...

I'm checking for spark with the plug, maybe I should just go get a plug tester for the sake of it. My brother is coming by today, so I'll have him push the bike while in gear and I'll check for spark.

I guess I'll just buy the cap and keep my fingers crossed. Worse case scenario it's something I won't have to worry about in the future once I figure out what the problem is!

 

[teazer]

Any cap from any bike or car with points will do the job - I think. Go to your local auto parts store and grab one from the electrical section. I have bags of the things taken off bikes where I replaced points with electronic ignitions. If you cannot find one locally, PM me and I'll mail you one.

 

[Helve]

I was under the impression that you had to match the farad rating on such a thing, or risk premature damage to your points?

Stole this from another forum post I found on google:

I'm no expert on ignition systems, so like usually happens, someone will probably come along after me with the correct answer and make me look like a dumbass. But being an electrical engineer (read Geek), I can't resist taking a stab at it.

The condenser is an old time term for a capacitor. The reason it is there across the points is that without it, when the points open, the coil will try to keep current flowing, so it causes an arc across the points. This can wear out the points really fast, or even weld them closed. The condenser charges up, allowing the current through the coil to flow for a short time while the points are opening, so that the points get further open before the condenser stops the current flow. This keeps the arc from happening. Then when the points close again, the points discharge the condenser so that they are ready for the next cycle.

So back to your question.... I would guess that the value of the condensor (capacitance value in Farads) is different between a 6 volt and a 12 volt system. It is a bit of a balancing act to get enough capacitance to prevent the arc from happening when the points open, versus too much capacitance that can cause an arc as the points close and the capacitor is discharged. The trick is to get just the right amount of capacitance to make the points live a long and happy life. I seem to remember back in the dark ages when all cars had points, that the real car guys would look at the points after a few thousand miles and could tell if they had too much capacitance or too little by which side of the points had the pit, and which side had the "tit".

So guessing here, but I'd say the right condenser is better than the wrong one, but the wrong one is way better than none. If your points last reasonably long, then you've got the right one.

Geeky enough for everyone?

Terry

In essence, wouldn't simply disconnecting the capacitor eliminate that as a possibility? If it truly were the culprit, eliminating it from the equation would eliminate the problem. It's not essential to run the bike with, if I understand it's job correctly. I can understand why it would cause a problem if it were to go bad, but like I mentioned, wouldn't simply disconnecting it from the system be a good way to check if it really had gone bad? Perhaps someone with a bit more knowledge on the subject can enlighten me!

 

[teazer]

It is needed to stop arcing as the points open and I'm sure that there is a "correct" value but I'd guess that any good one would probably work.

Your ignition system will probably generate 1-2 volts at kickover and 10-40 volts at any sort of running speed, so I'm not sure that the 6v charging system is relevant to the discussion. Fortunately they are dead cheap and easy to try a replacement.

 

[Helve]

Points were grounding out, so now I'm getting spark.... across my points. Seems the condenser(capacitor) is bad. Going to call a few shops tomorrow and see if any of them have a condenser for a smaller displacement bike like a CB200/SR250. Thank you all for the help thus far!

Edit : Scratch that, found em on ebay, listed for a KZ250 but the part number matches. Ordered two so I have a spare in 35 years when the next one decides to go!