Expanded charging system guide (In progress)

[grizld1]

BWAHAHAHA! They've expanded your guide for you alright, Gary, with a little bit of whatever posted wherever so that any idea of organization you may have had becomes a distant memory and nobody can find anything without picking through everything! Now you know why 5twins and I did our writing and editing in a user-restricted board when we wrote the Carb Guide, and posted it in read-only form--guys just can't resist the temptation to post their personal problems in a reference thread, no matter how hard and often you beg 'em not to. But thanks for a noble effort!

 

[JAX71224]

Before you edited your post, it read as leaving the power on when changing from testing voltage to continuity.....................For a novice............as the Op must be or he would not be asking these questions........your post contained information likely to cause damage or harm..............making fun of the OP in light of me pointing out a correction to this fault is in poor taste....................

Mined you i am easily confused because i thought peanut butter contained Butter............ and Peanut was used just to scare off people who did not like peanuts

Just so y'all REALLY know......There are NO nuts in peanut butter! Peanuts are legumes like peas and some beans. Nuts grow on trees. So there.....

 

[JayR]

BWAHAHAHA! They've expanded your guide for you alright, Gary, with a little bit of whatever posted wherever so that any idea of organization you may have had becomes a distant memory and nobody can find anything without picking through everything! Now you know why 5twins and I did our writing and editing in a user-restricted board when we wrote the Carb Guide, and posted it in read-only form--guys just can't resist the temptation to post their personal problems in a reference thread, no matter how hard and often you beg 'em not to. But thanks for a noble effort!

 

[mcjongs]

I have a charging issue on my 77' XS650 C.
It has a Lucas Rita pointless ignition system workin OK i think...and a '' modern'' rectifier/regulator with green and brown wires for the brushes.. They are plugged inn as pr. picture.. The issue is that I would like to connect it directly to the wire harness /connector coming from the stator as I suspect a broke wire..but I do not know if the wires are connected elsewhere in the wiring loom.. i.e to the key switch.. so that I will get some malfunction doing that?
The bike I have ha for a year or so so not have had time to fix the issue or but as you see from the pictures it is highly needed.. I have ordered new brushes as the inner one is on the border line worn..

Any thoughts?
Also the connector to the right.. it is going to a weird small yelow ''box'' or unit wrapped in black rubber behind the battery box.. but I cant find it on the wiring scheme?

 

[gggGary]

Has it ever worked "Correctly"?

 

[mcjongs]

Actually I do not know.. as I haven't used the bike that much.. but I have had problems with it ''eating'' spark plugs.. and then I found info about the charging system about whatever ignition system you have... spark will be weak when battery voltage decreases.. I have now a brand new AGM 15 Amp battery but no charging as voltage go down to 12 v from 12,7 v when running (without lights on) I thought it was eating spark plugs due to low compression and oil smoking so I have now refurbished the engine with new Heiden Tuning 750 kit and a Shell #1 cam. etc. I post a picture of the bike as it is now with a Velorex side car.

 

[5twins]

The small rubber box behind the battery is usually the light checker. It monitors the tail light, illuminating a light on the dash if it burns out. On a '77 model, you should have the early, simple 3 wire version. You can do away with and remove it without having to jump any wires. Simply unplug the unit and take it off the bike.

The original regulator had a green wire running to the outer brush and a black (ground) running to the inner brush. There was a brown running into the unit but it didn't go to a brush directly. It was a switched power wire from the harness (turned on and off by the key). The regulator used it to monitor the voltage in the system and also to supply power through the green wire to the outer brush when charging was required. Basically, the regulator would turn charging on and off as need be by controlling when power was fed into the green wire.

 

[mcjongs]

Thanks for explaining.
So it might be I have a broken black wire somewhere between the regulator- connector to stator...? There is also mentioned in the forum about nylon washers or screws for the brushes.. Is that applicable for my system?

As all the functions for brown wire, kill switch, horn blinkers and brake light are OK I will assume this is OK.
Never the less I should wait for the new brushes and also do a wire clean up in the headlight.. As you can see it will be challenging :-(

 

[gggGary]

It sure is fun trying to sort out 2 or 3 problems all at the same time isn't it?
Especially when some unknown PO just started cutting twisting and taping.
So you have an early brush block.
AND for purposes of discussion; you have some random voltage regulator that may or may NOT be one that will work with your charging system.
A schematic of your existing alternator.

Don't roll your eyes yet. (I saw that)
IMHO the first thing you need to do is find out WHAT regulator you have. Maker and part number and google or post it up here to find out what you have. Some will work with your brush block some will NOT. Then we need to figure out if it is wired correctly and if it WORKS, LOL. If it's not compatible it will be decision time. Change the regulator, or change the wiring.

 

[mcjongs]

Ok.. thanks again for valuable info.. It is a Electrexworld.co.uk regulator..RR35 which should be right for XS650. https://www.electrexworld.co.uk/acatalog/RR35.html
I have Ohmed the wires and all normal. The rotor resistance is 4,3 Ohm. Should be 5,5 Ohm? Not yet Ohmed the outer magnet white wires..
If the U= R * I is applicable in this it will only give stronger field with 4,3 Ohm compared to 5,5 Ohm.. ? It could be that I'm just left with short brushes.. ???

 

[gggGary]

yup looks right for an early alternator.
4.3 IS down in the "toasted" range Yes you will need sort out that snake pit in the headlight bucket.
Gotta hate folks that use random color wires.

 

[gggGary]

a stock rotor reading 4.3 ohms has sections of coil wire shorted together it does NOT improve it's charging function. Nice try.

 

[5twins]

Yes, wait for the new brushes. A brush worn too short can lose contact and stop the charging. I suggest you clean the slip rings too. Really dirty slip rings can lose contact with the brushes and stop charging as well. Measure the voltage on the brown wire in the harness that the reg. plug connects to. It should show about 12 volts when you turn the key on. If it does then at least the reg/rec unit is getting power. But, that still doesn't mean it's working, sending that power out on the green wire to the outer brush when charging is required.

If you only tested the charging output at idle then around 12 volts is correct. You won't see an increase in charging output until you rev the bike up. When revved to about 3K or 3500 RPMs, then you should see up around 14 volts output.

 

[grizld1]

Mcjongs, there is no regulator that's "correct for the XS650." There are regulators that are correct for alternators with one brush grounded to the stator housing, and regulators that are correct for alternators with both brushes isolated from the stator housing.

 

[5twins]

...... and there is where issues arise with getting a replacement. The 650 used both alternator versions during it's production. The earlier bikes up through '79 had an alternator with a grounded inner brush. The '80 and later bikes had an alternator with both brushes isolated.

 

[gggGary]

That regulator looks to be right for the early style, checked the website, has the correct dual early plugs and mentions points models..........

 

[mcjongs]

I measured the white wires from the stator and it seems i get 0 Ohm between them...?
Is that correct?

Edit.. New measurement with correct setting on the Fluke showed 0.6, 0.7 and 0.7 Ohm and also fully open towards ground.

Should be ok then.

 

[mcjongs]

Well.. sad news.. :-( Despite received and installed new brushes it will not charge.. I honestly do not know what to do further... I have in order a new reg/rectifier..
https://www.ebay.com/itm/Voltage-Rectifier-Regulator-for-Yamaha-XS850-826cc-XS1100-1101cc-XS750-747cc/263698389046?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
I hope this will work.. should be same as for XS650 I hope.. but much cheaper..

Jon

 

[gggGary]

The rotor resistance is 4,3 Ohm. Should be 5,5 Ohm?

yup looks right for an early alternator.
4.3 IS down in the "toasted" range Yes you will need sort out that snake pit in the headlight bucket.
Gotta hate folks that use random color wires.

a stock rotor reading 4.3 ohms has sections of coil wire shorted together it does NOT improve it's charging function. Nice try.

 

[mcjongs]

Hmmmmmm... it drained from 12,5v-10,7v during a 20 min test run. I hate that only 1 Ohm shall be that important..
Had any luck cleaning the rotor with any solvent like brake cleaner etc.?
I'm thinking more and more in the direction of a PMA kit.. change out the old shit but on the other hand I DO NOT LIKE TO GIVE UP.

The 750 kit with Shell #1 cam was really fun though! With my ''fat as''friend in the sidecar.. it nearly lifted front wheel on 1st- gear on some heavy throttling Fantastic grippy those Mitas with 6,5mm ice studs. When I throttle it goes to left and let go the throttle it goes to the right.. Great fun!