Charging questions

[Gibson]

Hi folks, I've been trying to adjust the regulator on my 76 model. The electrical system is all original. When the revs are increased above 3k it is over 15.5V. I've tried backing off the regulator adjustment to bring it down to around 14.5V, but it wont keep the battery charged. It will slowly go flat. It is a new battery. Is a solid state regulator the answer?

 

[XSLeo]

That's one of the things with those mechanical regulators. If set high enough to charge the battery for a lot of around town stop and go traffic it over charges at highway speeds. If set to not over charge at highway speeds it won't keep the battery charged at slower speeds.
Yes, a solid state regulator is a very good upgrade. I would also swap out the rectifier for a more modern version too. The Selenium rectifier as used stock is not a very efficient unit. On Ebay you can get 3 phase rectifiers for around $5. One of about 25 amps is good. A higher amp one will work but is larger and costs more.
A bit of shopping will find a regulator for around $25 to $30. A bit of wiring and they can be done as a plug and play.
All the info you need is on here.
You can spend a lot more money and get a combo reg/rec unit. These start in around $100 and go up from there.
Leo

 

[5twins]

You can usually find the VR115 regulators on eBay for between $10 and $20 .....

http://www.ebay.com/itm/NEW-VR115-V...ash=item1c4bb2d423:g:SMMAAOSwQItTzH16&vxp=mtr

 

[Gibson]

Thanks. Anyone try the Mikes part? I noticed from the instruction sheet on line it is up at around 15V. The price is a bit high, but it looks like it has the connectors and all. I don't want to cut any of the stock wiring...

 

[XSLeo]

You won't alter any of the harness wiring with the mods I mentioned. Take the old reg and rec, cut the wires of as close to the reg and rec as you can. Use these wires to wire to the new parts. Then they just plug in the harness the same as the stock parts.
Leo

 

[Gibson]

Thanks. I kinda did not want to cut up the stock regulator as it is a good part (as poorly as it does function). If I can find a block connector that would be cool. I really like the auto type regulators for 15 bucks on Ebay...maybe Im being unrealistic, but some day I would like to restore this bike to all original form. I will do any mod to it, as long as it is completely reversible. But for now I want to ride it!

 

[XSLeo]

There are lots of places you can get connectors that plug right into your harness.
Mike's has them.
Leo

 

[Gibson]

Awesome! Thanks Leo. I will go that route. I was thinking of taking a trip that will about 800 miles this spring. Trying to get it so its dependable...if possible.

 

[retiredgentleman]

Go with a nos VR-115 regulator and a new 3 phase rectifier. They will make a big improvement to the charging system. Its also wise to replace the old # 1157 tail/brake light with an LED tail/brake light, which will reduce current load for the alternator.

Here are the details for rewiring:
http://www.xs650.com/forum/showthread.php?t=21485

 

[rainycity]

I thought I had read somewhere on here that they dont charge when just idling and
needed to have the rpm`s up some.

 

[jussumguy]

Yes that's true. The best upgrade I ever did to my bike was mount a volt gauge on it. That takes all the guessing out of it. I idle around less these days.

 

[Gibson]

Bought this today...cant wait to install it. Hopefully no more choice between boiling battery, or not charging.

 

[Gibson]

Looks like I've got 14.7 at idle 1300rpm and 15.5 at 3000 rpm. Works great...Thanks all.

 

[xschop]

Quick question I have a 72 xs and my battery wasn't charging I was riding off the battery so I finally ordered the reg/rec off tc bros and my battery still isn't charging...I have a simplified wiring harness running points and kick only no other accessories....I tried the slap test and it's slaps but very light but I feel it pull to the case any ideas I'm getting frustrated and not riding today when it's 60 degrees here in Milwaukee Wisconsin is making me mad Any help if appreciate it

 

[louis]

Light slap might be a symptom of worn alternator brushes?

Remove your alternator cover, then remove alternator brushes and measure them, cheap to replace if that's your problem.

Go read Curly's charging system guide if you haven't already using the custom google search function.

If it isn't your brushes, I'd be testing your rotor using a voltmeter.

 

[xschop]

To be honest I have my manual and everything but haven't touched anything inside my alternator cover and to be honest it's daunting to me and I don't wanna mess anything up if you know a step by step link around here I'd greatly appreciate it because I have a feeling they just might be the brushes

 

[xschop]

And where would you or anybody suggest to buy year correct brushes?

 

[louis]

http://www.xs650.com/forum/showthread.php?t=10561

It's all there in posts #1 and #4 by Ggggary, and then I asked a buuuuunch of questions on later pages about specific issues not that dissimilar to yours. Checking brush length is only 6 screws total!
Unscrew your alternator cover, unscrew your brushes, measure them. Done.
To test your rotor, measure brass ring to brass ring, should be about 5 ohms after a clean with some 1500 sandpaper. If not, might need a new rotor.

Once you know what you are doing you can test brushes and rotor in about 5 minutes, nothing to be scared of.

New brushes are here:

http://www.mikesxs.net/parts/yamaha...2-fits-70-79-oem-256-81611-10-256-81612-11-00

 

[retiredgentleman]

Looks like I've got 14.7 at idle 1300rpm and 15.5 at 3000 rpm. Works great...Thanks all.

Those voltages are too high. The voltage should never exceed 14.5 volts.

Perhaps you should borrow another voltmeter from someone, and take more voltage readings, in case your meter is not accurate.

Are these readings with no headlight on by any chance? If so, turn on the headlight and measure voltage.

Are you sure you have the new regulator wired correctly? Does the black wire from the regulator go to a good ground, such as the common black wire in the harness, or to bare metal on the frame. You can't connect to the metal battery box for a ground, because its insulated by rubber bushings.

 

[Gibson]

Thanks Retired. Yes it was with headlight off. I have a halogen headlight. I used the stock connector ground. Plugged into harness in stock location with 3 pin style connector block. Wired it just as shown in posted diagrams on site. I just ran a quick test to see if it works. I will throw up some readings with headlight on later today. I hope it drops down a bit under load. Ill be riding today for sure as it will be around 60 today in the North East! Thanks Much!