Advice on parts for building charging system needed

cruzin

cruzin

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Hi, I have a 1976 xs650. That I am bobbing. I was trying to identify electrical parts and the wires did not match up with colours in the books schematics. The harness has been hacked and parts with different coloured wires been added.
This is where I am asking for information to set up my system, I will list what I would like to do.

I want to use my original alternator if it is good. Can someone tell me if I can test it while the engine is out and partially dissembled? And how to do that.
I will be using a pamco with e advancer unit for spark.

I want to build the charging system. I have read about using the VR-115 regulator and building the rectifier with the radio shack parts, 276-1185. This all sounds within my ability to do.

Problem is I have read a lot of posts and am uncertain of witch parts to obtain. I have read about regulators used for amc, jeep, chrysler and the VR-115. And will I need to un-ground my brushes?

So given that I would like to use stock alternator if its good and a pamco with e advance and a battery.

Speaking of battery I read a post and sxLeo stated that he used a 8cell battery and it even would do electric start. I would keep the electric start on the bike if I can find a battery small enough to fit in my home made electric box.

Any help with parts list will be appreciated.
 
To test your alternator you need to test the ohms of the rotor and stator. On the wires coming up from the alternator to a large plug. It has three white wires, a black, a green. There is a sky blue wire in the plug, this is the neutral light.
Next to the plug is a single yellow wire with a bullet connector. This is for the safety relay.
To test the ohms on the stator you use the three whites. Number them 1,2,3. No use your meter on it's lowest scale. If digital the 200 ohm scale. Now touch the meter probes together. You will get a reading, remember this reading. It is the reading of just the test leads.
Now test the white wires, from 1-2, 2-3 and 1-3. They should all read the same.
This test reading will be off just a bit. Now you need to subtract the test lead ohms from the stator wire ohms.
On one of my meters the leads test out at .7 ohms. If I test the stator and get a reading of say, 1.6 ohms, I subtract the .7 of the leads from the 1.6. As in 1.6 - .7 =.9
Your meter is probably has different lead ohms. One of my meters has .1 ohms.
Now switch the meter to a high ohm scale, like 20k. Touch one probe to the white wires, the other to the body of the stator. You should get an infinity reading.
On the rotor, easiest to remove the stator but you can test it by just removing the brushes and the brush holder. Use the low ohm scale, put the probes in where the brushes were. Touch one probe to each slip ring on the rotor. this should give you a reading of about 5.5 ohms. A bit higher is ok but much lower is not. Remember to subtract the lead reading.
Now use the high scale to test ohms from the slip rings to the body of the rotor, again an infinity reading is good.
If you read the threads on the replacement regulators and rectifiers you will find which reg works with your brush set up. I think the VR115 is the one that works with the 70-79 brushes.
I use the Chrysler reg, a bit cheaper but you need the nylon screw mod to unground the brushes. I had my 75 set up this way and it worked very well. I had an 82 stator that I swapped in. This way I did need the nylon screws. It works well too.
On the rectifier The Radio Shack rectifiers work well. Radio shack is most every where.
Some of us have found 3 phase rectifiers on Ebay. Can be found for around $4 or $5.
These simplify the wiring just a bit. You don't need one of the great big ones, A 30 amp/1000 volt one is fine.
Leo
 
Thanks XSLeo, Ill get started on testing this today. In one of your replies to a guy on this very subject you mentioned a battery you used and it also worked for starting with the electric starter. Can you elaborate on it. You said it was a 8 cell I think. thanks again.
 
I found a vr-115 and ordered it. Also I found a 30a 1000v rectifier. It is a bridge rectifier. Ill post its description and a picture. Want to make sure I order the right part.
Description: BRIDGE RECTIFIER SQL 30-10 RATED 30 AMP 1000V 3 PHASE

I am in process of testing. I only have a digital VOM and

I got .2 reading between all white wires

but I DO NOT have infinity between any white wires and the body of the stator. Do you mean there should be no continuity between the white wires and the housing? If so my meter does nothing with any of the 3 white wires and the stator body, I do not have any continuity between these wires and stator body.

I do have 5.0 between the 2 slip rings.

And the brushes are at least .5 inches long.
 

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I ordered this rectifier for the project. I do not know what all the terms mean about it. But hopefully it will work for me.
 
Have you seen XSLeo's write-up?

http://www.xs650.com/forum/showthread.php?t=9625

The regulator, rotor brush layout, and rotor wiring scheme need to match. Early 70-79 rotors were powered by the regulator, while the later models had a powered rotor, grounded by the regulator.

Watch for this distinction while reviewing any 'charging system' and 'vr-115' threads...
 
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TwoManyXS1Bs said:
Have you seen XSLeo's write-up?

http://www.xs650.com/forum/showthread.php?t=9625

The regulator, rotor brush layout, and rotor wiring scheme need to match. Early 70-70 rotors were powered by the regulator, while the later models had a powered rotor, grounded by the regulator.

Watch for this distinction while reviewing any 'charging system' and 'vr-115' threads...
Click to expand...

good point Twomany and a good way to describe the difference between the two grounding systems but I think there is a typo in the date range :wink2::laugh:
 
I have a couple of those 3 phase rectifiers. They are easy to hook up. The 3 blades along one side have a wavy emblem beside them, these are where the 3 white wires hook.
The two blades, one is positive the other negative. They are marked as such.
70-79 used the regulator to send power to the rotor, the 80 up sent power to the rotor and the regulator grounded the green to let power flow.
Or think of it this way, 70-79 the reg controlled the voltage before the rotor, the 80 up reg controlled the voltage after the rotor.
On the stator the .2 is low. It may still work but not as well as it could.
A lot of people are swapping the stock alternator for a PMA. You might put an ad in the Parts Wanted section of this site. Someone may have a good stator for you. If not Maybe Ebay.
The battery I use is a Ballistic 8cell battery. It's 4.5 inches long, 2.5 wide and 4.25 tall.
It weighs 1.7 lbs. Has a burst cranking of 240 amps. That's what stated on the web site now, used to state 275 amps. Either way that's a bit more than the stock batteries 180-200 amps.
They also have a 12 cell. 4.5 L, 3.5 W and 4.25 T. It weighs a bit more. 2.5 lbs. and has 360 burst amps. They make them in an L version. The difference is the terminals. On the regular the positive is on the left, the L version it's on the right. Not a problem either way.
You can find them on Ebay for around $140. A bit expensive but the weight savings and extra cranking is worth it.
Leo
 
thanks everyone for the replies. I will read Leo's post hopefully that vr-115 is what I can use. Ive got a 81 motor that I just acquired a few weeks back I may check the stator on it. But have to research to see if it is compatible. I would like to pma in the future but did not want to shuck out the 300 or so for the complete kit! Ive checked on the batteries and I think I can add something to the bottom of my electronics box I just finished. And I have seen some that I think would fit inside of it along with regulator, rectifier, relays and fuse panel. but Ill have to wait and see how much room I have left. thanks again I appreciate it.

Ok found a post by retiredgentelman stating that the vr-115 is used for the 70-79 xs bikes. found it!
 

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Got my vr-115 today in the mail. It will nicely fit in my electronics box.
And the orange and yellow join together to battery +
the black to battery -
and the green to positive brush of the alternator

is this correct? thanks
 
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