Rewiring Stator and Regulator Swap

[Drewcifer]

So I wrote about this last week and since 3 of us have had the same issues, I figured it's time for pictures.

I lost my voltage regulator. It shorted out and then the bike lost tons of volts with the key on. I could trickle charge it over night but it bothered me how much I was losing power just keying the bike on. To me that spelled a problem.

The first stop. Regulator:

After I tested it over and over I realized it was just dead. it tested 112 ohms when it should have tested at 10.5.

Mailed away for a new one. ebay. Got it. Didn't solve the problem. Next stop, stator. Used the pizza box trick to keep track of the bolts as they came out of the bike. They're all different sizes, so keep them organized.

Park bike over an oilpan. I put my Kickstand inside.

Loosen the clutch cable adjustor nut at the handle bar.

Ziptie the clutch cover out of the way

I removed all the bolts and finally got inside the stator. You can see my wiring is worn through.

Once I slide the fiber shell back, I saw a break in one of the wires. With all the white wires separated and not touching, they tested correctly for ohms. So I figured "i've gone this far. might as well replace them."

I got 8 feet of wire from the boat store and started cleaning up the wires and soldering the new wires to the old wires.

I degreased the coil and stator in hotwater and dawn dishsoap. This is extreme but I needed to be sure there were no metal shavings or contaminants causing shorts. I knew the windings were insulated in epoxy so I used electrical contact cleaner to get the water off and a compressed air supply on a hose. It's safe enough for DC motors, safe enough for me.

It took a while to make sure no soapy film remained, but it was very clean after. So was the clean stator cover. I was sure then there would be no dirty oil causing shorts.

Pushed them through the rubber grommet,

Slid heat shrink over them, tinned them, soldered them. I tinned too much for too long, and they became stiff and linear instead of flexible. So I had to do them twice. My tip is to solder them at a 45 degree angle and nip off the overlap. They have to bend to get up and through the grommet. 18 gauge is fine. I used 16 and it was too thick in my opinion.

Checking coil and rotor fitment to be sure there are no rubbing parts/shorts. I just slid it over the rotor. It had space all around.

When I was done I made sure they were all testing correctly on the ohmeter and put the replacement gasket on that I made. Sealed it up with red gasket seal.

Stator with clean wires and clean wire covering.

I put the stator back on after I verified that it all lined up correctly, and tested right with the ohm meter.

You can see the new neat heatshrink tubes I used to route the bundles together back to the connectors. I had to find it at an obscure old electronics place that is probably barely surviving, but they had heatshrink in 4 foot lengths, unlike radio shack.

The foil keeps the oil off the pipes and prevents smoking when you re-assemble/restart the bike.

Lastly I had to wire in my replacement voltage regulator when I found that the alternator was rewired and still not producing voltage. So I powered up a wire with + voltage and touched it to the end of the green wire I'd just re routed. The voltage rose, meaning I had a dead regulator.

I bought an r-292 at Oreilly and wired it into the bike's loom, using solder.

Happily with it all soldered together, I got the right volts at idle, and at rev.

It took a while to gather the knowledge, but the work itself didn't take long. I actually pulled the stator about 4 times before I rewired it looking for issues, So by the last time I could get into the stator and back out in less than an hour. The messiest part was the oil that would come out of the timing cover/stator case. It does need a layer of gasketing there, or heavy paper. I used file folder sealed in place with red gasket sealant on both sides, and it's been fine.

Best of luck to those others with voltage issues. You'll be sorted soon enough. It just takes patience. When you see the magic volts you'll feel pretty proud.

Safe riding

Drewcifer

 

[dO-bOy]

I love it. Thanks so much for documenting the process. Makes me 100x more confident now as I'm going together started tonight.

Mad props!

 

[ThePsuedoMonkey]

Nice write up!
You don't need to worry about oil causing short-circuits, though: motor oil doesn't dissolve salts, so there are no ions to carry any current through it. If you don't have a pizza box to keep track of the bolts, the rule of thumb is that they stick out about twice their thickness (diameter) when you push them into their hole. I don't know if you'd absolutely need 4' segments of heat shrink, since you can overlap about 1" and probably be fine with smaller ones.

 

[frwinks]

Nice, it's on my list as well... The fiber sheathing is gone on various sections of my three wires as well

 

[drewpy]

cool write up and gives confidence to others.

 

[Drewcifer]

my pleasure fellas. Could not have been done without the Jedi Council.

 

[XSLeo]

Well done. The only thing I might add is that I have used cereal boxes, like Cheerios or such to make gaskets for thing like that for years. A thin coat of grease or anti-seize on both sides of the gasket, seals the gasket and prevents it from sticking on the case or cover if you need to remove the cover later. This way the gasket won't break and can be reused.
Your old reg looks to be a mechanical one. They are ok. They can be adjusted to set the cut off voltage. One thing about them was that set to keep the battery charged at lower rpms around town they tended to be to high at extended highway speeds, over charging the battery. Set to not over charge at highway speeds won't charge well around town.
Your new solid state reg won't do this. It cycles faster than the mechanical reg so works better. Keeps the battery charged at low speeds and won't over charge at higher speeds.
This keeps the rotor cooler and prolongs the life of the alternator.
A very good upgrade.
Leo

 

[Drewcifer]

Thanks Leo. Even Mike at Mike's XS wanted to know if this worked or would blow up my battery. Many people did this mod at xs 650 but we didn't have documentation that it worked on the smaller xs bikes. Now we know.

 

[dO-bOy]

FYI I don't use any gasket material other than Black RTV when I seal my side covers up. No leaks at all. I was taught to only finger tighten, leave it for half an hour to set a bit, then tighten the cover down.

 

[Fixit]

Hey Man,
I just wanted to say thank you also! Checked all the wiring down low, before I came across your write up, but the old regulator was giving me some strange readings. I believe it charged fine with rpm, but wasn’t putting out enough at idle and slow speeds. After reading your write-ups, I double checked stuff: razor blade stuck to the cover, so I went for the regulator swap.... I'd been chasing down an intermittent misfire that would cause my bike to die once in a while at the stop light. If you blipped the throttle as soon as you heard it, it wouldn’t stall, but if you just let it idle, it would eventually die.
I also used the R-292 regulator, but I cut the plug off the old regulator and soldered it to the new unit. So far, everything seems to be working fine. Ran out of time, but it was charging, and I let it run for about 5 minutes, and didn't hear that intermittent misfire, like I usually do. Can’t wait to take her out for a ride!

One question: Does this regulator ground through the body? Or is the old wire lead fine?

Thanks!

Chad
1978 XS400-2E

 

[Drewcifer]

The whole circuit is a ground loop, so it enters the reg on the green wire and and exits on the black. If voltage is high it dumps it out the ground. If it's low, it powers the field coil and fuels the charging process...

Funny thing is mine is doing what you said...and I did the swap! I have to find out why. I think my points are slightly out of adjustment because starting takes a second longer on the starter button. Most of the time it's an electrical connection drifting loose someplace. Gremlins!

 

[Fixit]

Thanks!
OK, so I spent the whole day working on my bike yesteday, and doing other things to it. I also removed the cam cover and re-torqued the head, (slight oil leak, but good compression). Then resealed everything, and reset the points and timing... So, it maybe the timing is the issue. I'm wondering if the vibes loosen up the points plates and points screws enough to allow them to get out of whack. My points plate screws were pretty chewed up from years of service, so I replaced them with stainless, allen head cap screws. Worked very well, and gave me a little more adjustment on the plate. I was thinking about adding some lock washers, but I'll wait to see what happens.

This has been a very strange problem, for me too. Because at mid to high RPM the bike pulls really hard up to about 70-80, but then I let off, because she needs new tires, and I'm not that brave/stupid... I've been through the carbs 2 - 3 times and everything looks good. I must have a rare bike, because almost all of my electrical connections look pretty good. (I did replace the holder for main fuse, in the fusebox though...)

I've been riding for about 4 years now, and all of my bikes have been old/used ones, because they fit the budget, and I'm a bit of a motorhead, it used to be old Chevy Novas back in the day. I'm trying to get this bike running good for one of the students in my youth group. This is a great bike, right size and all, but I have too many projects and gotta let some of them go... Here in WA state, (your brother probably knows), their charging me just as much for tabs on my bike, as they do my old van, crazy. You can't tell me that a 350 lbs bike causes as much wear and tear on roads as a 3500 lbs car... I'm done ranting!

I'll try to keep you posted if it goes back to intermittent stalling...

Thanks!

Chad

 

[Drewcifer]

No sweat. yeah, Molly was up there originally. Biker Wizard shot her down to me in a friendly Uhaul via a Vespa Pervert/surfer executive.

I think I dialed my adjustment screw in too much. Its between the carbs, at a 45 degree angle, white knurled knob on my bike. Will tinker today.

Your new vreg will bring you much joy!

Drewcifer

PS, today I'm replacing the stator on my buddies Ducati. Funny how even the ohm specs on that stator ar the same as ours! LOL (PS, Ducati loctites freaking EVERYTHING! No wonder those bikes go 200 mph. Every single screw has loctite!)

 

[XSLeo]

On the regulator, it's not a ground loop. Power is fed to the reg on the brown wire. If the voltage is below the regs preset 14.5 volts it sends full battery voltage to the feild coil on the green wire. This excites the stator to make electricity.
This electricity charges the battery. Once the battery voltage reaches the regs preset 14.5 volts it stops sending power to the feild coil.
The mechanical reg did this but cycled slowly, a few hundred times a minute. The solid state cycles faster, thousands of time a minute. This faster cycle raste keeps the battery charged better.
Leo

 

[XSLeo]

If your new reg looks like this, then it grounds through the wiring.

 

[Drewcifer]

Leo, thanks. It could have been clearer.

You don't need to ground the r-292. The ground is part of the wiring and not the body in this case.

Better?

 

[cabbott12321]

So Drewcifer, on my other threads you keep telling me to check my stator wires. Well I finally got the cover off, with a lot of elbow grease and an impact driver to find a very disgusting sight. I thought it'd be good to put these pictures on this thread so people can see what can potentially be under there.

I obviously need to replace some gaskets cause this is just gross. Thanks for this write up though! It'll be so helpful in fixing these wires!

 

[ThePsuedoMonkey]

If there was a "naughty area" on the xs, it'd be under the sprocket cover! Make sure to route the repaired wires such that the chain doesn't break 'em again.

 

[Drewcifer]

I call that stuff SPROCKET FUDGE!

It aint purty! Never is! Found on every bike I've worked on! No matter how old!

Good news, stator looks clean and healthy. Bad news, the wire shroud around your stator wires and the reference wire look to be totally scrapped. Easily cleaned/replaced.

I suspect beneath that fudgey exterior and the hempish shell on the stator wires is a broken wire that shorts in all that oil. that's what I had to go up against. Usually that shell gets stiff like a plastic butter knife and hacks its way slowly through the shell of stator wire. Fix that for good and your charging woes will vanish.

For about 8 bucks in tinned thinwall you can go to a boatstore and get the wires you'll need to remove those shite ones and replace them with up gauged wire. I went up a gauge so now I won't have overheating issues. You can do the same but they're harder to solder. Read my write up and Drewpys how to rewire where he starts with this stator do over.

Note, the wires have to be soldered to the ones inside the stator at a 45 degree intersection. They can't be butt soldered because they won't bend through the oil safety grommet in the safety wall.

I wish you VOLTS my friends.

Drewcifer

 

[Inked400]

I just read your thread and hoping tomorrow i can say thank you . i bought my 400 as a project just something to mess around. i built everything on it and it came to wiring and i was lost. i am not running a starter, turn signals or anything . i only have a headlight and a tail light and a toggle switch hidden to kill power to my battery . I was not charging so i am out of ideas so i just ordered the r-292 about 10 minutes ago. Im praying it works so i can finally ride my bike after 2 long years of fab work on it.