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Discussion Starter · #1 · (Edited)
okay. I just got this bike and the only trouble I have with it is a battery problem. When I got this bike the old owners told me they took it to a shop and the mechanics told them that it was a bad rectifier. The battery will charge and I can run it for a while but then usually after I shut it off, the battery has been drained. Now the battery was new when I got it and I have been recharging it a lot since it's my only means of transportation. oh yeah, so I got a used rectifier from a reliable dealer on ebay and changed it out and the same problem exists.... I am not sure where to go from here.
 

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Now the battery was new when I got it and I have been recharging it a lot since it's my only means of transportation. oh yeah, so I got a used rectifier from a reliable dealer on ebay and changed it out and the same problem exists.... I am not sure where to go from here.
Probably NOT a good move, buying a bike with a known problem like that. :frown:

New or not, the battery still could be bad.
On a bike that old, it could have bad connections too; both ends of the main battery cables would be suspect.

I've seen several reports lately about bikes of that vintage having charging problems. Is there a switch to turn the headlight on and off ??

Before you go throwing away any MORE money on stuff that probably isn't bad in the first place.....you need to get a multi-meter so that you can check the battery voltage, both after charging and a rest and when the bike is running. If you don't feel comfortable (or qualified) to do that, start looking for a shop that will check it out for you.

If you intend to continue the repair process yourself, you also should get a shop/repair manual.
 

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Discussion Starter · #4 ·
okay, so since then I have ran my friend's battery, because my battery is going bad, and I just put his on my bike, then started it and stopped it quite a few times, then I let it run for a while, checked the voltage (it was 12.7 before I put it on when I checked it) and then I re-checked it after running it and it was 12.6. soooo I tried that process over again then it was 12.5....so I know my battery is bad but something still isn't running right. I do have a switch for my light but it only goes from hi beams to low beams and that doesn't work anyways. The moment I turn the ignition to run the light comes on.

and with a mulit-meter, how do I go about checking it. do I turn the bike on then use the multi-meter to the part?

and what are you talking about with my stator?
 

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Check the wattage of the headlight.If it is higher than the the factory spec,it could slowly discharge your battery as you are riding the bike,especially if you are cruising around town at say,4000 RPM.
My 1975 CB 360 has an on-off head light switch and the stator kicks out more wattage when the light is on. Go figure.
 

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and with a mulit-meter, how do I go about checking it. do I turn the bike on then use the multi-meter to the part?
I think maybe you've already made enough readings that we can say that your charging system is not working......maybe. Successive readings made across the battery that keep going DOWN usually means a bad charging system.

You need to measure the battery voltage before starting; that is your reference voltage.

Then start the bike and measure across the battery again.....at idle (~1K rpm) then at 2K and 3K rpm; just guess if you don't have a tach.

If the charging system is working right, the running voltage should never be BELOW your reference reading and at some point should be above 13 volts, maybe as high as 14.5 if the battery is low.
 

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Discussion Starter · #7 ·
Check the wattage of the headlight.If it is higher than the the factory spec,it could slowly discharge your battery as you are riding the bike,especially if you are cruising around town at say,4000 RPM.
My 1975 CB 360 has an on-off head light switch and the stator kicks out more wattage when the light is on. Go figure.
other than having the right tool, how exactly do you check the wattage?
 

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Discussion Starter · #8 ·
I think maybe you've already made enough readings that we can say that your charging system is not working......maybe. Successive readings made across the battery that keep going DOWN usually means a bad charging system.

You need to measure the battery voltage before starting; that is your reference voltage.

Then start the bike and measure across the battery again.....at idle (~1K rpm) then at 2K and 3K rpm; just guess if you don't have a tach.

If the charging system is working right, the running voltage should never be BELOW your reference reading and at some point should be above 13 volts, maybe as high as 14.5 if the battery is low.
I can't really check it at those rpms, bc my bike idles too high. Like usually around 4k. So what would be another way?

and I know my responses aren't the best, and I really don't know a lot about bikes or mechanics, and I am learning, but I really am just trying to say I'm not shooting down your answers on purpose... I just have a fixer upper with a lot of problems, that's all.
 

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other than having the right tool, how exactly do you check the wattage?
On the old glass headlights,,the wattage is usually formed right on the glass.I think what happens is people [including former owners] just go to an auto store and get an automotive headlight that is too much power draw for the bike. To find the correct bulb,wattage,find a service manual,or ask the counter guy at a Honda store.
If you know how to set your meter to ohms,my service manual has a procedure to test the rectifier without the bike running, if you are interested.Tell me what colors the wires going into the rectifier,and if they are the same as mine,we will take a stab at it using my service manual.
 

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I can't really check it at those rpms, bc my bike idles too high. Like usually around 4k. So what would be another way?
You are going to be overwhelmed if you try to fix everything at once.

Those two things are likely not related so pick one and fix it first. I'd go for the engine/idle/carb thing first because it should not be ridden like that......and if you can't get that fixed, it won't make any difference what the electrical system is doing (or not doing).

If those voltage readings you reported were at 4K rpms and with a weak battery, the odds are about 90% that the charging system is shot. You will need a shop manual to check the individual components.
 

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Discussion Starter · #11 ·
You are going to be overwhelmed if you try to fix everything at once.

Those two things are likely not related so pick one and fix it first. I'd go for the engine/idle/carb thing first because it should not be ridden like that......and if you can't get that fixed, it won't make any difference what the electrical system is doing (or not doing).

If those voltage readings you reported were at 4K rpms and with a weak battery, the odds are about 90% that the charging system is shot. You will need a shop manual to check the individual components.

Yea I know my engine idling at 4k rpms isn't good but I want to solve my electric problem....you must of read my post wrong when I said my bike idles at 4k, and you somehow got that I checked my battery and it was at 4 volts. My battery is bad. I know this. I have used a new battery and it still drains. I need to diagnose my electric problem.
 

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My battery is bad. I know this. I have used a new battery and it still drains. I need to diagnose my electric problem.
I know exactly what you said and what you meant.

To fix the not-charging problem, you need a shop manual and a multi-meter......or a LOT of money to just replace parts......or a shop that will do it for you.

Which of those methods you choose depends on your individual situation.
 

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Discussion Starter · #13 ·
I know exactly what you said and what you meant.

To fix the not-charging problem, you need a shop manual and a multi-meter......or a LOT of money to just replace parts......or a shop that will do it for you.

Which of those methods you choose depends on your individual situation.
The information you are giving me right now is nothing new. You are just telling me things I already know. I'm trying to get a manual and a multi-meter. Obviously I could take it to a shop and pay out the nose, but I am here at this website trying to find help. If you can, help me. Don't tell me things that are plain as day. That doesn't help me.
 

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The information you are giving me right now is nothing new. You are just telling me things I already know. I'm trying to get a manual and a multi-meter. Obviously I could take it to a shop and pay out the nose, but I am here at this website trying to find help. If you can, help me. Don't tell me things that are plain as day. That doesn't help me.
Ok without a shop manual how do you know what to check? He is giving you good advice and these guys on here spent years learning what they know. All you keep telling us is what we already know as well. Your bike is not charging. It's a simple system really. The alternator generates AC volts that the rectifier changes to DC volts to charge the battery. Get a manual and start testing and that will tell you what is not working. If the used rectifier is good then you can figure it is the alternator. Check for broken or frayed wires. If you don't find any then it's probably the alternator itself.
 

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The information you are giving me right now is nothing new. You are just telling me things I already know.
When giving advice in a forum like this, we have to assume NOTHING and start at the very beginning.

Often the biggest mistake a new rider often makes is trying to jump ahead and thereby overlooks the actual problem.

The second biggest problem for new posters in places like this is leaving out critical details and then getting ****y when someone asks about something that they didn't mention. Sometimes the help stops completely after that. :frown:

People who fear "paying through the nose" at an experienced shop OFTEN end up paying MORE through the nose because they are inexperienced or stubborn or both and it ends up costing them MORE to do it themselves.

The more you post, the stronger my feeling gets that trying to do this yourself might be a mistake. I hope I'm wrong.
 

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Hey,Tim

Let's just start over.This is the honda page. Right at the top of the page is Honda Wiki.The manual is there. Maybe not the exact year for your bike,but good enough to use. Let's also assume that the idle of the carbs has the simple solution. There is a knurled round screw in the general area the petcock that you can turn with your fingers. It is a throttle stop screw that does about the same thing as a brick on the gas pedal of your car. Try to adjust it and see if you can get your idle to about 1500 or so.
Even if you do not have a manual, some of us have bikes that are very similar to yours and can help. The Rectifier test is pretty easy on those old Hondas,and you do not even need a manual for that.
Hope to hear back from you---Slum
 

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When giving advice in a forum like this, we have to assume NOTHING and start at the very beginning.

Often the biggest mistake a new rider often makes is trying to jump ahead and thereby overlooks the actual problem.

The second biggest problem for new posters in places like this is leaving out critical details and then getting ****y when someone asks about something that they didn't mention. Sometimes the help stops completely after that. :frown:

People who fear "paying through the nose" at an experienced shop OFTEN end up paying MORE through the nose because they are inexperienced or stubborn or both and it ends up costing them MORE to do it themselves.

The more you post, the stronger my feeling gets that trying to do this yourself might be a mistake. I hope I'm wrong.
Dude, with your people skills, patience and understanding.Have you Ever considered being a Vo-Tech instructor?:rolleyes:
 

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Start the bike and put your meter leads on the battery and kick the RPM's up to about 1500-2000

If your reading is less than or equal to the battery voltage when the bike is off, then your stator is not generating enough juice, you have bad cables, or the regulator is going bad.

If the battery is not getting charged, then the battery can have enough in it to run the bike when fully charged, but not enough to start it the next time. The amps needed to cold start the bike are more than is needed to run it at idle.

Keep it simple and take it one step at a time. Otherwise, you'll replace alot of stuff you don't need to :)

To give you an idea: My 86 Magna 700 is 13.2V at idle and 13.8 to 14.1 volts at a rev ;)
 

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Dude, with your people skills, patience and understanding.Have you Ever considered being a Vo-Tech instructor?:rolleyes:
Never had that title but have done a LOT of training over the years.

At least in those situations most of the folks paid attention and didn't get their panties all in a bunch because the instructor knows more about the subject at hand than the students.

It seems like the "disease" common to teenagers......I know everything about everything and YOU know nothing........now carries over to more and more people in their 30's and beyond......and always being able to find another nut case somewhere on the net who agrees with you doesn't make matters any easier.

I try to be nice but sometimes it is hard; sometimes REALLY hard. :(
 
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