4 questions about old motorcycle ignitioin system.


4 questions about an old motorcycle ignition system. Electrical questions are 2 and 3, and maybe 1.
Well, I got my '69 Honda CB450 reassembled, just in time for the last 2 days of warm weather.
1) I tried to start it and it didn't start, and I had other things to do for 2 or 2.5 hours, and when I got back to it, I saw that I had left the ignition switch on**. This model has two carburetors 2 coils, 2 sets of points and 2 condensors. One coil was warm, and it had 1 to 2 thimbles of waxy stuff which had come out of it. Did I ruin the coil? If not yet, will it die in 5 or 10 hours of use? Is there some way to repair the damage I did? (It's not clear I'll be able to find a new set of coils for a 1969 motorcycle.)
2) One set of points was open and one was closed. I put a thin piece of cardboard between the closed points, turned the ignition on again, and measured the voltage across the points. The circuit is battery plus terminal - coil - (points/condenser, where these two are in parallel with each other) - ground - battery negative terminal. So it seems to me that the voltage should be battery voltage, about 12 volts. Or should it be less until the condenser fills? The voltage was 6 volts using an analog meter, and didnt' seem to be going up. I thought, Oh my gosh, I've run down my brand new battery, but when I checked the voltage there, it was at least 12.5.
BTW, how much damage *did* I do to the battery by running one ignition coil for 2 to 2.5 hours?
3) On the other circuit, I tried to evaluate the other condenser by turning the ignition off and measuring the resistance across the points, which I'm pretty sure is across the condenser. I expected to see the resistance pretty low as the condenser filled and then increace. But the resistance was close to infinity. If I tested right? that means the condensor is open, but that shouldn't keep the cyclinder from firing, right? IIRC, mostly what it means is that the points would pit quickly?? If I can't get the right condensor quickly, what value and type would I need to jerry rig one temporarily?
4) There is a wick that lubricates the cam and keeps the rubbing blocks from wearing out. I can't remember what I'm supposed to put on the wick. What do I use, and if they don't still sell it, what do I buy instead? :) (I had trouble remembering this 30 to 20 years ago, too, but I haven't had to worry about it since I've had all-elecctronic ignitions on my car)
**If it had started, I would have remembered to turn the ignition off, but since it didn't, I didn't. My fault.
BTW, the starter motor worked well, even though I hadn't checked it out, and the kick starter seemed to maybe be working well, or at least differently, even though it would go so far and then stop dead without cranking up till now. The clutch disengaging is working fair, and the throttle doesn't spring back quickly enough, even though I oiled all 3 cables (2 carburetors) and the throttle plates moved easily after soaking the carburetors in Permatex.
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My bet is that if the coil is leaking it is screwed. I doubt it is from one time of leaving the key on, just old age. There is a lot of interchangability on coils and condensors, if it will fit it will probably work . I had a couple of old motorcycle coils lying around, I haven't seen them for a couple of years, but they are in my shop somwhere.
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I would imagine that, like cars with 12 volt ignition running on points & condenser, there is a resistor in line to drop the voltage down to 6 volts at the distributor. Locked my keys in the trunk once on a fishing trip and had to jump the ignition, running 12 volts direct to the ignition. By the time I got home, the points were completely fried and car stopped running.
Tom G.
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Coil should not have gotten warm, its fried.
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wrote:

It is possible it will fail, or has failed. Warm? Not hot? it is also possible it has water contamination already.

Typically the point surface (the contact) will burn or oxidize. I'd recommend replacing the points.

About a million dollars worth... <g> This happened to cars all the time. Usually damage is limited to burning the points and should not damage the coil.

Ignition point cam grease. It's special... (Really!) probably hard to find, but whatever you use do not apply too much!

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wrote:
Those old bikes are easy to keep running, they are relatively simple to fix and adapt parts to them.

One set of points stays closed pulling 3-5 amps down through the coil and dissipates ~60 watts. That's an unhealthy amount of power for 2+ hours. All the power is dissipated in the primary winding and if it didn't get hot enough to melt the enamel on the magnet wire it will be good to go.
Measure the resistance of the primary and compare it to the cool coil. You may not be able to discern a single shorted turn with just an ohm meter, and a single shorted turn will adversely affect the operation, but it is a place to start . . .
I did something similar with my Triumph twin - heated the coil something fierce because I left it on.
You don't say how your coil is made. The old Triumph had a coil that was in a metal can and filled with oil - like an auto coil. A lot of Jap bikes use molded coils. If the stuff oozed out and the primary is still OK - the coil still works(?) then you still may want to give it an epoxy coating to keep moisture out. And the waxy stuff is probably wax - wax was used in old plastic cased coils and expands a lot when heated.
My technique for flaky coils with cracked plastic cases works well for keeping water out:
Big obvious cracks - Clean surface with a wipe of acetone, if it is glossy smooth I rough it up with sand paper (not emery - it is conductive) or a file, then just apply some silicone to the crack - work it in and around the area.
If the coil may already have moisture in it, I dry it, then place it in a warm (150F) oven overnight or use a light bulb and tin can to heat it gently. Air has to circulate around the coil as it is warmed so don't close it up tightly leave a way for fresh air to get in and carry the water vapor off.
Plan B: Dry coil, prepare surface - paint entire outside with epoxy - thickened epoxy that sets slowly is best. I have a rig with a motor that slowly rotates the coil along its axis for an hour as the epoxy cures - that technique is best when it is an older coil subject to lots of hairline cracks in the case.

It should indeed be the battery voltage with no coil completing the circuit. That would be troubling to me. Even if there's a dropping resistor, with no current flowing except for the little the meter needs, it should not be dropping voltage - so how's the other side? This is two identical circuits - are both 6 volt?
The cap is .5 microfarads or so in a standard Kettering ignition - it would charge instantaneously - in human terms.
If you measured it just after using it to heat the coil perhaps the battery was 6 volts at that time? (they do recover when allowed to rest, after a steep discharge)

Can't say. Was the battery hot? Did you put it on a slow charge immediately after you discovered your mistake?
I lost my alternator on a trip and ran the bike until it wouldn't go or turn the starter - I got it towed to my friends house and it sat with a discharged battery for three days. I rigged some wire to her car battery and when I got the alternator sorted out the battery was still OK and started the bike.

The condenser should read infinity - it charges too fast to see it unless you were to use a high value series resistance and then watch it charge through the resistor (the formula is resistance (in ohms) times capacitance (in farads) to find the time constant - to reach 66.6% of full voltage). You have .0000005 farads and <1 ohms - that's a half microsecond to charge - don't blink a blink is 1,000 microseconds.

They usually use something like a light grease worked into the felts. Something like "Lubriplate" would be ideal - or just some 30 weight if you aren't picky.

I take a plastic bag and punch a hole in the bottom. Take the top of the cable off the lever or twist grip and put it through the hole in the bag. Use electrical tape to seal it well then just suspend it and fill it with oil. Penetrating oil on very gummed up cables, but 30 weight is fine for most sluggish cables. The oil will eventually run down through the cable sheath and free the cable.
Place in Canada has some good deals on coils and such for older bikes (a fraction of list) www.partsnmore.com $35 minimum - but a coil will cost you $30. Shipping free to the US. That's where I check first for a part. Place called cycle recycle is also good.
-
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wrote:
Cycle recycle url http://www.crc2onlinecatalog.com /
Condenser: Motorcycle will probably idle normally with a completely disconnected (open) condenser. Will misfire when RPM is higher than idle.
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i would sand the points with some emery and see if its fireing. if it is its hard to say how long that coil will work. i got a 73 cl and honda dealer still has parts for it,so give them a call. if you go to ebay and put your model number in the search i bet youll find some things for it.did you check your compression. and valve adjustment. lucas
http://www.minibite.com/america/malone.htm
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