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Hi all, picked up an absolutely beautiful 1971 Honda CL100 from a guy about 2 cities away here in the south Seattle, WA area. Says it doesnt run.

Get it home, titled, plate issued, smell the fuel, doesnt smell much. Smells varnishy.... so we know it hasnt ran in at least a year. Says he tried to get it going with no luck.

SO! I check the new looking 6v battery and my electrical tester says its pumping out a mighty 6.5v. So the battery is good. I was almost hoping it was bad. Easy 30 dollar fix. Go to take the tank off.

Unplug wires halfway down the neck of the frame, leading to the front of the bike... (approximately 12" away from ignition switch) these wires are HOT. Good to go...

Go to test wires coming OUT of ignition switch... NOTHING with ignition switch on/off.

So i've ordered a new ignition switch. I hate to just replace random stuff, but hey battery has power and I'm not seeing anythign comign OUT of the ignition. So i'm going to just keep making my way down the system. NO headlights/dash green neutral light on. They're all off. Acting like a dead battery.

Someone else have this issue with any of these little CL70/cl100/cb100/SL100's?
 

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The battery may indeed have voltage. But it may also have no amperage. Those 6v systems were pretty weak, and any sulfation in that battery could kill sufficient amperage to power anything. If your local dealer can load test a 6v battery, this can be confirmed. You should also check the main fuse and other fuses.
 

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The OP's thread is over two years old... so I hope it got her running :rolleyes:. FYI tho.... These run off a magneto and will start on a dead battery.... and there is only one main fuse.
 

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I did check the main fuse. Main fuse is good. Guess i dont know how to check for ampreage. Sorry guys I'm not an electrical guru. Normally just give up and try and bring it to someone. i want to figure this out on my own.

Someone else suggested a new regulator/rectifier. Any good in this?
 

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I did check the main fuse. Main fuse is good. Guess i dont know how to check for ampreage. Sorry guys I'm not an electrical guru. Normally just give up and try and bring it to someone. i want to figure this out on my own.

Someone else suggested a new regulator/rectifier. Any good in this?
Not yet.

You have a spare headlight? Hook it up directly to the battery and measure voltage. If it drops quickly (like more than .5 volts in a few minutes) then your battery is on its way out.

You should still get something even with a dying battery though, so my guess is the ignition switch as well. Multimeter will tell you for sure. Red (maybe red/white) wire to the ignition should read 6V all the time. Black wire coming out of the switch should get voltage when key is turned out.
 

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Starting on page 90 of the service manual.... everything on your electrical system: http://www.dotheton.com/downloads/Honda CB100 CB125 CL100 SL100 CD125 SL125 Workshop.pdf
Thanks Dean!!

Not yet.

You have a spare headlight? Hook it up directly to the battery and measure voltage. If it drops quickly (like more than .5 volts in a few minutes) then your battery is on its way out.

You should still get something even with a dying battery though, so my guess is the ignition switch as well. Multimeter will tell you for sure. Red (maybe red/white) wire to the ignition should read 6V all the time. Black wire coming out of the switch should get voltage when key is turned out.
Great info here! Snreir, appreciate your reply. WHy would a 6v battery ready 6.5? Suprised it wasnt down to 4-5v being sitting without being ran. Love these little bikes. 1 cyl, 1 carb, cmon if I cant figure this out, I shouldnt be tinkering at all.

IMAG4343.jpg
 

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It's typical for batteries to read up to a volt higher than their "actual" rating. Funnily enough, if a battery is reading it's rated voltage, that usually means it's dead (or will be soon). 12.6 - 12.8 is considered a healthy reading on a 12V battery. Less than 12.5 means the battery needs to be charged.
 

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"Probably" fine. The true test for a battery isn't voltage, it's amperage.

If a battery fails a voltage test, it's definitely bad. If a battery passes the voltage test, it could still be bad if it fails load testing.
 

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Testing a battery with a volt meter is an incorrect way to test a battery. A battery must be under load to properly test it. Also, instead of ordering an ignition switch - you should have sprung for a shop manual for this bike - if you have one great if not I'd recommend getting one.

Battery testing must be under load - the quickest way to test it is to connect it to a charger. If it looks like it is charging up then your battery is most likely ok. I always like to check each cell using the battery tester with the colored balls in the tester (I forget the proper term for this tester). This will give you the condition of each cell after you have charged the battery. If the battery has a full charge and all 4 balls float - then that cell is perfectly fine.

Your battery also runs through your kill switch. I've seen more problems with kill switches that ignition switches. This is where your manual will come in handy as most will show an electrical schematic. Unfortunately without basic electronic understanding the schematic would be like giving a map to your goldfish. Basically, the schematic will show you the pathways of all your electronics. (I'm going to post this to re-read your problem)..

Hot wires are not a good sign - that could mean your battery is being shorted to ground and the wires are overheating - (it really gets interesting when they catch on fire). I would recommend using a ohm meter to test continuity between different points on your wire circuit. (continuity means you measure zero ohms between two points) (most volt meters also include a ohm meter function)

You mentioned your neutral light doesn't work - does any of your winkers or headlight or taillight also not work? If the answer is yes then use the volt meter function to see if your battery voltage drops when you turn on the ignition key with the lights on (place the red lead on the + part of the battery and the black lead on any ground point on the bike. With the key off - you should see voltage, with the key on you should see just a slight drop in voltage. If the voltage drops to zero - that should mean you have a short in your wire harness somewhere. If that's the case, recheck your battery is charged and visually check your wiring harness. (Weak batteries tend to drop to near zero volts when testing under a load)

If the voltage just drops a little bit - then you need to chase the power through your bike wiring harness. Some auto mechanics will use a lighting tool to chase power through the circuit. Thats a screw driver type tool with a point and a ground wire attached to it and a light mounted to the end of the handle. You can use this tool to chase your power through the ignition and kill switch. If power is getting through the switches then use your schematic to follow the proper wire to one of your lights. You should be able to follow the power right up to the tail light or winker (depending which light your chasing). Hope this helps a little - good luck..
 

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If that's the motor I think it is you probably need to reset points after you clean out carb
I've seen them where red wire breaks off back of ignition switch then they get hot wired, although it's more likely something is plugged in wrong.
Did you remove fuse to check it? you need to as they can be broken internally but look fine
Post a pic of the other side (left side of bike)
bmartin, its a specific gravity tester, only tells you if the acid is good and as battery was charged it won't give an accurate indication of battery condition
 

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While you are waiting for your new ignition switch to arrive, just connect all the wires going into the ignition switch. This will "turn the switch on". Then you can check all the other electrical components.

Also, when you say "these wires are HOT" I hope you mean they have voltage, as opposed to being hot to touch....because the 2nd one isn't good.
 

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Discussion Starter #16
It's typical for batteries to read up to a volt higher than their "actual" rating. Funnily enough, if a battery is reading it's rated voltage, that usually means it's dead (or will be soon). 12.6 - 12.8 is considered a healthy reading on a 12V battery. Less than 12.5 means the battery needs to be charged.
This is the perfect time to Check into a few things. Instead of bringing it into a local cafe/vintage type shop here about 40 miles away, I'm going to do what Id normally not do. I'm going to start replacing a few things, 1 at a time til I find it.

I've ordered an ignition and its shipped, After taking the tank off, the petcock will not 100% stop fuel, so i'm removing that and going to replace that as well. They're both on the way. After installing new ignition I'll see if I can get power PAST the ignition wires going OUT, if I do, we'll turn the key on (regardless of whether the green neutral light is on, on the dash, or if the headlight/taillight is working) to see if we have spark.
 

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Thanks Hillsy, yes, they have voltage. 6.5v. Not hot to touch.

At this point fellas, I dont have lights on ANYWHERE. I need to remove battery and put it on a load. THanks for the suggestions. you guys are awesome. Will reply back in a few days with outcome, step 2.
 

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BTW - from memory my XT500 battery used to run at around 7.2v when the bike was running, so it's possible your 6.5v reading could mean your battery is a bit "low".
 

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Discussion Starter #19
BTW - from memory my XT500 battery used to run at around 7.2v when the bike was running, so it's possible your 6.5v reading could mean your battery is a bit "low".
UPDATE!!!!!!!!

1. New ignition switch with keys showed up from California (thank you ebay!) for a mere $19 bucks! Pulled the bike out, once again checked power of the battery in a sitting state. Exactly 6.0v.

2. Install new ignition, Check for power, and we NOW have the green neutral light working on the dash! We also have power to the headlight, and taillight!

3. Check for spark, we have spark!

4. Onto the gas tank. The bike hasnt been tabbed since 97. I added metal washers, nuts, and 20 2" gold screws. The gold screws were what REALLY cleaned the tank out! Shook it back and forth with about a quarter gallon of gas. Strained/drained tank FOUR times. Inside of tank still rusty on the neck portion, but the lowers and sides are pretty damn clean. Very impressed! After complete, petcock opened and compressed air blown from the petcock INTO the gas tank. Sounds clean and clear. Ready to mount.

5. Installed gas tank, added 3/4 tank of gas, and switched valve to reserve. Didnt look like much fuel ran out into the fuel filter.

6. Fuel filter installed backwards. Reinstalled, and fuel is coming out of the tank but its limited. slow stream and gas tank was checked prior to running.

7. Time to pull off the side covers again, she wont start. Shes not getting fuel. Full carb tear down. I take my time and this carb was immaculate after a full cleaning. Clogged jets, and the float had welded itsself with goo, to the float bowl.

8. Reassembly, once again, no fuel. Hrm...... Fuel filter removed. We have fuel. Fuel filter, though appears clean, is JUNK. Time to get another tomorrow. So for today only I run a new piece of hose from the tank directly to the carb. No filter.

9. kick, kick, kick...nothing. Drain screw on bottom of carb bowl cracked, and fuel begins to come out. kick kick kick. About ten kicks in, "SPUTTER, POP!" My face turns to a grin, and 1 more kick. She fires up like its 1971. Perfect idle, no smoke, clean running motorcycle :cool:




Need to thank all of you who offered input! What an outcome to about a 4 hour day on the bike! So great! Horn works, lights work, tach lights work, EVERYTHING works!!!
 
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