Charging problems? (HELP!!)

[Bowtied]

Okay guys as you know i just got my bike coming up on a week now. Well last night about 915 i was leaving my work and it was dark out. Well when i fired the bike up i was talking to a buddy of mine outside and i noticed that my headlight was acting funny.

When the bike is running in nuetral and i rev it up the light gets brighter. Now i'm not a class A dumbass but on a car that would lead me to believe there's some charging problems. Now i've never worked on a bike before but i don't want to get stranded. Is it a battery problem? Or is it a magneto problem? I'm new to working on motorcycles so bare with me! lol! I just don't want to get stranded somewhere. It still starts and runs fine everytime but the light acts up on me.


I don't know if the shop put a battery in it or not? I haven't called them yet. But any help i coul get on this subject would DEFINATLY help as i am supposed to go riding this weekend with my pops and my uncle! Thanks fellas!

[geniusloerts]

mine does pretty much the same thing, but it is hardly noticable unless i am really looking for it.

I had a 68 F-100 that did the same thing but it was a Votage regultor, I dont remember if our bikes have them......????

Mine has done that since I got it over a year ago and havent had any serious problems

[Bowtied]

Humm...? I assume that since its still starting and running fine that there shouldn't be a problem with it. I just don't want to get stranded out in bum freak egypt and need a battery to get it home! hahaha! Just tryen to avoid the difficult part!

[geniusloerts]

if you do a search or go into tech tips there is a page about checking the charging system to see if it works or not. you will need a volt meter.


yeah, i am all about avoiding the "Deliverance" situations

[Bowtied]

hahaha! Squeal like a pig boy!!!


Hahahaahaha! Yeah I'll call my boss and see what he thinks. And i will look up that page too. Thanks man!

[FJ111200]

The neutral light is supposed to get brighter when it's revved up, it means that the charging system is working.

[Bowtied]

I'm talking about my HEADLIGHT. My headlight gets brighter and kinda dims down with the revving of the bike. (if that makes any sense) I'm new to the motorcycle mechanics. So i have to reach out to people that've dealt with it before haha! Thanks fellas.

[randy]

Bowtied,

That is normal operation, to a point. Hook up a multimeter to the battery and check the voltage while it's running. Should be 12v at idle, 13.5-14v at 4k-5k rpm.

it's obviously charging at some value, because the headlight came on, if it wasn't charging, the headlight would not come on at all.

[Ivan]

Mine does the same thing. Remember, the headlight is the highest load the charging system experiances. On a car it is not uncommon to see 100 amp alternators. 100amps x 12 volts = 1200 watts. I highly doubt our bikes even come close to that. I would guess we get more like 350 watts, at full charge. Under idle conditions, it will be considerably less.

It has been stated in other threads that the primary side of the ignition system will stop working if the system voltage drops under 10.5V. Also, the tach reads the AC signal from one of the stator legs. If the bike is still idling well, and the tach isn't erratic, I would say you don't have much to worry about.

[webbcraft2150]

Diming of the headlight at idle is kinda normal for these rigs. I think it is Geezer who makes a kick ass regulator rectifier that helps this problem go away. I noticed that when I finally put a new battery in mine, most of the problem went away. I also converted my tail/brake light to LED's, this took a big load off the charging system at idle. IF you have any doubt about the condition of your battery, replace it. A weak battery puts added strain on an already taxed charging system. Follow the tech tips on checking out your charging system. A good way to check your battery is charge it fully, check the voltage, let it sit overnight and check it again. You might be surprised how much the voltage drops overnight, a sure sign of a battery on its last legs.

[strippedFJ]

ALL bikes from all manufacturers did this back then. Go and check a CB750/Z9/XS1/GS750 from the 70's they're even worse.

And these bikes were considered to be just the dog's bollocks in comparison to equivalent Euro/Brit manufacturer's of the time. Their lighting was provided by Lucas - AKA "The Prince of Darkness"

[fredintoon]

Hi Bowtied,
it's the poor man's voltage meter. If the headlight gets brighter as the engine gets above 1,500 rpm or so it shows the lamp is getting the 13+ Volts from the alternator instead of just the 12+ Volts from your battery and that the charging system is working as it should.