72 XS650 elect. issue

[cjrenick]

Well I just got my bike back together after top end rebuild. It is a hardtailed bobber with headlight and taillight/brake light only. Went to start it up and had no power. Put charger on and it showed it was basically 100% and had lights with charger on. Started bike up and later noticed that that I had no lights. Bike running fine other than needing to adjust carbs and timing. I managed the motor work, but when it comes to electric I am clueless. I guess my first step is to take battery in and have it tested. Is there a way to test fuse or just look for break in the middle? Any other suggestions? Stupid ? but how does the bike keep the battery charged up without an alternator?

Thanks,
Chad

[tango911]

they have a stator that sends charge to the regulator/rectifier. Its basically an alternator, a coil and magnet that spins off the main crank. You prob have a lose wire somewhere from hooking it all back up.
Fuses can go bad and still look like they are good sometimes. If you buy a cheap volt meter you can prob trace out your prob. Im off on mondays and could help. Im a honda guy but decent at finding electrical probs.

[cjrenick]

Thanks for the response Tango. I picked up a volt meter. What are the steps to check and what readings would I be looking for?

[cjrenick]

Just checked battery with the volt meter and it reads 10.01v.

[cb500bobber]

Okay it should read 12 so it sounds like you have a charging problem I would check and make sure all your connections are good

[cjrenick]

The lights should be working when charger is connected right?

[tango911]

Assuming your battery is a good one and fully charged. Put the meter on your battery with the bike running at about 3500-4000 rpms you should be getting 14.3 - 14.7 vdc. much more or less you could have a bad Voltage regulator or rectifier. Some bikes have all in one some have both a regulator and rectifier seperate components.

1st i would get your battery tested. fully charged and tested under load. just take it to the auto store they will test if for you.

[novafrk]

Hey Chad

I always get a manual, they will have a complete trouble shooting guide. How to test the regulator, rectifier, stator etc. It's the easiest way to figure out your issues. Good luck.

Eric

[cjrenick]

Just ran the bike and it was reading 14.1v at idle. Not sure of rpms since I do not have a tach. Hopefully in the next day or two I can get the battery tested.

[cb500bobber]

Yeah that's a little to high for idle at idle it should be around 13

[cjrenick]

Only thing on my bike electrical is motor, starter, headlight, and tail/stop light. How many fuses should I have? Looked at it tonight and only found one. It says 30A 32v. Did not getting into all the wiring. If there are more they are hidden pretty well.

[leadkrm]

Maybe we will have to have a couple of guys make a house call and come help u out if u can't get
It
Figured out

[cb500bobber]

This is a possibility

[cjrenick]

Ok, found out today that the battery is bad. I guess it has been a long time since I have bought a battery for a bike. Thought they would cost around $30. My ? is do I get one for a 1972 XS650 or can I get by with a smaller battery since I am running very little in the way of electrical and being kick start? It is just one thing after another with this bike. Also, left side carb is leaking .

[cjrenick]

I GIVE UP!!!! Got the new battery today and still no lights. I can not figure out what it could be. The fuse was fine. I was thinking the switch, but if it was bad would I be able to start the bike up? It is just a three way switch, do not have a key.