1981 XS650 Special - Build Thread

They're over 40 yrs old.... and first generation i/c electronics at that. They're a little long in the tooth. You might source another one, but who knows how long it will last. :shrug:
 
Jim amongst others convinced me to go modern cheap automotive replacements. Almost a "no-brainer" if you are not bent on a totally stock original.
On this bike I'm not bent on originality but rather what works and reliability! I do like sticking with stock whenever possible but I want to ride with confidence too.
 
Are these OEM reg/rect somewhat reliable? If so I'd like to just source a good used one. If they're prone to problems then I'll go the route of building one.
Yeah the older mechanical regulators seem to survive the ages better than "early solid state" electronics. I've seen a fair number of the all in one stock regulators go tits up.
 
On this bike I'm not bent on originality but rather what works and reliability! I do like sticking with stock whenever possible but I want to ride with confidence too.
I would like to think that I have "riders". I have a modified 77 that had an updated ignition system when I bought it but stock regulator and rectifier. When my regulator acted up this forum helped greatly going to an automotive regulator. I am guessing it is all in the tech section. My '81 Red Bike is all stock with regards to charging and ignition. I carry a plug in GN250 ignition module in case I need it. I suppose I will face failures in the most inopprotune times in the future but in the old days, they called that "adventure".
 
So far, the used original I put on my '83 is holding up OK. The actual original was fried when I got the bike because the chain had cut into the alternator harness and obviously shorted some wires together, lol. I had a spare in my stash so for the time being, it's on there. But, I have a voltmeter installed so I can closely monitor charging output. That's something you should also consider regardless of what you do with the reg/rec. You can get a cheap one off eBay for less than $10 and just "strap" it to the handlebars with cable ties, lol .....

SimpleVoltmeterMount.jpg


I do have the automotive regulator on the shelf just in case .....
 
So far, the used original I put on my '83 is holding up OK. The actual original was fried when I got the bike because the chain had cut into the alternator harness and obviously shorted some wires together, lol. I had a spare in my stash so for the time being, it's on there. But, I have a voltmeter installed so I can closely monitor charging output. That's something you should also consider regardless of what you do with the reg/rec. You can get a cheap one off eBay for less than $10 and just "strap" it to the handlebars with cable ties, lol .....

View attachment 257730

I do have the automotive regulator on the shelf just in case .....
There are 100 ways to mount a cheap voltmeter to your XS 650 to monitor the health of the charging system and not 1 good reason not to if you ride it regularly.
 
Are these OEM reg/rect somewhat reliable? If so I'd like to just source a good used one. If they're prone to problems then I'll go the route of building one.
The one on my XS1100 has over 100,000 miles and 45 years on it. My XS650SK has 65,000 miles on the original RR. A used one might work.
 
I get it and I agree. I've sourced a good used one and I'm going to build one of the automotive versions described by Jim as a spare. That way I can have an extra to carry around with me.
I’ve been carrying a TCI and a pickup coil. I carried a rotor and puller to the last 650 Society rally. It got installed in another bike. Mine was running @Jim rewind, so I carried one as a courtesy. Since I never suffered a regulator failure, I don’t carry one. The bike will go 200 miles or more with the battery running only the ignition.
 
I don't feel the need to carry those spare parts. As Marty said, the bike will continue to run off the charge in the battery for quite a while, longer if you can turn the lights off. If my voltmeter ever indicates a charging issue, I'm pretty confident I can make it home before the bike quits.

I've "retroed" my '83, getting rid of the added safety features (sidestand and clutch switches), and doing away with the auto-on headlight relay. I added the right handlebar control with a headlight on-off switch from a '77 (I think) model. I also connected the tail lights into it and disconnected them from the ignition switch. They no longer come on with the key and are now controlled by the handlebar light switch too. Now, the older models with a single tail light bulb weren't such a big deal, but many of the later Specials have 4 bulbs out back (2 tail/brake light bulbs, 2 license plate illumination bulbs) and that's quite a bit more draw on the battery.

Your '81 doesn't have the sidestand switch and relay, only the clutch one. Removal instructions are here, see post #55 .....

https://www.xs650.com/threads/200-special.51454/page-3

And if you'd like to fit a headlight on-off switch, here's how .....

https://www.xs650.com/threads/retrofitting-headlight-on-off-switch-to-81-83-model.58167/
 
Day 49

I got my parts in to build the reg/rect.
IMG_4355.jpeg

I also had bought a reg/rect off eBay thinking that would be the easy fix. Well, nothing ever goes as planned does it.
The reg/rect I bought off eBay would blow the main fuse as soon as I'd turn on the key, so I thought I'd go ahead and build one to see if the results would be different. They were.. The one built still produces the same results as what I had before with my original where it charges but when revving to about 3k rpms it's right at 18 volts. Seems as though something else is my problem. I gave up for today cause that barn is cold. I'm open for opinions on what might be the problem.
 
Day 51

I was able to get my charging issue squared away. I had pinched a wire when putting the clutch side cover on at some point.

IMG_4370.jpeg


I figured while I had the air boxes out and the tank off I might as well do the mod @gggGary mentioned to the BS34 Needle Jets. I put the washer under the clip as shown in the diagram and WOW what a difference. I definitely had a slight hesitation/flat spot around 3k and now it's completely gone. Thanks for the suggestion!

When I was buttoning everything back up I got to cleaning on my side covers. Somebody at some point sprayed who knows what on them. It was clear to a certain degree but I don't think it was any kind of paint because with just a little acetone it came right off. It was kind of pliable. I was able get it started peeling and pull off in some spots in chunks. Underneath this goo the paint looked really good.
IMG_4377.jpeg

Good productive day!
 
Day 53

Today I used the @gggGary Brake Bleed method and it worked great! I was going to go for a ride but my recently rebuilt front caliper was sticking. I took it all back apart, cleaned up the piston, put it back together and bled it with Gary's method. I wish I would have learned that trick years ago!
 
Day 55

Got me a matching Yamaha Helmet. I remember when I bought a new Special II back in '81 that the dealer had matching helmets and I bought two of them. I found this one that matches the '81 Special "Frost Silver" for my bike. Pretty cool.
IMG_4421.jpeg

IMG_4423.jpeg
 

Attachments

  • IMG_4425.jpeg
    IMG_4425.jpeg
    295.8 KB · Views: 14
Back
Top