Looking for opinions....

[Sir Real Ed]

Great info so far guys. thank you.

The front end on the 77 is a bit of a mystery. Previous owner said it was a Vision front end.... except the Vision had trailing axle forks and a 18" wheel. This has center axle forks (37mm tube dia. 185mm center to center, XS is 34mm tube dia & 186mm center to center) & a 19" wheel. The only two Yamahas I know that used that wheel style were the Vision and the Seca 400. Seca 400 was a single disk in the US with an 18" wheel. I have seen pictures of dual disk Seca 400's but I assume they were non US models. I'll have to look at some old pictures. It might be a Seca 550 front end. I've never seen a dual disk Seca 550.

The front tire is a 100/90-19 and rubs ever so slightly on the fender. The fender looks like a Seca 400 fender to me. At first I thought "Aha! He installed a 100/90 tire instead of a 90/90 tire!" But the 19" wheel is a head scratcher for me. Need to stop relying on memory and find some pictures. I know the 650 & 750 Seca wheels are the swirl spokes.

I appreciate the info about the stock electrical system. After reading a couple threads I'm thinking of a Mike's XS wiring harness and then simplifying it into a consumer's wiring harness and a charging system harness as per the book The Yamaha XS 650 Engine by Hans J. Pahl. But I still need to do more research. I'll be pinging you guys more in the future.

Leaning heavily towards EX 500 carbs. I have some SV 650 switch gear laying around, I might use that. And in my imagination, my flat tracker seat might look good with a DR 650 rear fender and DRZ 250 tail light.

Need to research more, learn more and think more. Nice to have other running machines.

 

[Sir Real Ed]

The stock 650 system is an automotive style 3 phase alternator. It's output is controlled by the regulator. It isn't running full blast all the time, only when need be. The old mechanical regulator used on the '79 and older systems is a bit crude and it's output is somewhat erratic. But you can replace it with a more modern automotive regulator for $20 to $30 and fix that. The crude open air rectifier can also be replaced with a more modern unit for about $10. Making those two changes will reduce the strain on the other "big ticket" components in the system (stator, rotor), and make the alternator's output more stable and consistent.

5twins,

Any vendors and part numbers you can recommend for automotive regulators and rectifiers will be most appreciated. thanks in advance.

 

[Sir Real Ed]

Mystery solved. Forks and wheel are from the 82 Yamaha 650 Seca Turbo (19" wheel). The front fender is probably from the 82 Seca 400 (18" wheel).

 

[5twins]

The stock 650 charging system came in two versions, the difference being in how the brushes are wired up. The earlier system, used up until 1979, grounded the inner brush full time and the outer brush was sent power by the regulator. The 1980 and newer systems are kind of the opposite of that. The inner brush was fed constant switched power (fed power whenever the key is on) and the outer brush was fed the ground by the regulator. So, two different types of regulators were needed, depending on how the brushes are wired. In the automotive world, these are called an "A" type (ground regulating) or "B" type (power regulating). So, you'll need to determine which charging system type you have in order to know which type of regulator you'll need.

Stock, the '76 and '77 models would have the earlier type charging system that uses a type "B" power switching regulator, but that could have been changed. The later alternator will swap right on. It's also possible to re-wire the brushes on the early system so they will work with and need the later type "A" ground switching regulator. If you can get us some better close-up pics of the alternators you have, we can probably I.D. them for you.

 

[Sir Real Ed]

I appreciate that 5twins. I will post pics when I get a chance.

 

[Sir Real Ed]

Does anyone have any experience dealing with TC Bros? I like the idea of starting with one of their chopper wiring harnesses, then upgrading regulator and rectifier with 5twins (or other knowledgable folks) recommendations.

I can see starting there, and perhaps at a later date upgrading to the Boyer-Bransden ignition.

thanks in advance.

 

[Beags64]

Never anything electrical but plenty of other stuff. Always had good service, quick shipping. I think they've got a 15% off sale going on right now too.

 

[XSLeo]

I browsed through this thread and didn't see one thing I find as very important on your bikes. Good paper. Most places it's tough to get a bike on the road without good paper.
I wouldn't go to far on either till I had good paper. No sense in spending a lot of time and money if you can't put them on the road.
Leo

 

[Sir Real Ed]

Agreed. I do have a title for the 1977.

 

[Sir Real Ed]

The stock 650 charging system came in two versions, the difference being in how the brushes are wired up. The earlier system, used up until 1979, grounded the inner brush full time and the outer brush was sent power by the regulator. The 1980 and newer systems are kind of the opposite of that. The inner brush was fed constant switched power (fed power whenever the key is on) and the outer brush was fed the ground by the regulator. So, two different types of regulators were needed, depending on how the brushes are wired. In the automotive world, these are called an "A" type (ground regulating) or "B" type (power regulating). So, you'll need to determine which charging system type you have in order to know which type of regulator you'll need.

Stock, the '76 and '77 models would have the earlier type charging system that uses a type "B" power switching regulator, but that could have been changed. The later alternator will swap right on. It's also possible to re-wire the brushes on the early system so they will work with and need the later type "A" ground switching regulator. If you can get us some better close-up pics of the alternators you have, we can probably I.D. them for you.

Hey 5Twins,

Alternator pictures below. To my untrained eye, they look stock. Any Vendors and part number you can give me regarding good quality voltage regulators and rectifiers would be greatly appreciated.

 

[5twins]

You appear to have the original charging systems. That would call for a type B (power switching) regulator. The VR115 (or one of it's equivalents) is about the most common used. You can still buy them new at an auto parts store for around $30 but I shop eBay and sometimes have found them as cheap as $10. And as I mentioned, you can use one of the equivalents. These are the same unit with a different part number because they are from a different manufacturer. The VR115 is the Standard Motor Products part. Here's a few of the other ones you can search for .....

M5-701 12V B-Circuit (Regulated Power)
GRX-528 Motorcraft (Ford)
VR 1010 NAPA Echlin
VR727 Wells
1V1033 Airtex
C622 AC Delco
VR-1760 Ace
VR291 GP Sorensen
RAB 12A6 Electro Systems
R292 BWD
KVR179 Borg Warner
A71N AE

Personally, I've tried the VR115, a VR1010 (NAPA/Echlin), and a VR-1760 (Ace). They're all basically the same unit, some painted a different color, and all have very close to the same output (within a few tenths of a volt) .....

For a rectifier, we use one from the electronics world. This is a 3 phase alternator so you want/need a 3 phase rectifier as well. There's a ton of cheap ones from China on eBay and they have worked OK for many folks, but they have given a few guys issues. I guess that's to be expected with this cheap Chinese stuff. There's another better rectifier that many of us have used that hasn't given any problems to anyone that I'm aware of. It cost a few dollars more than the Chinese ones but is still only about $10. It comes from a wind turbine place called Windy Nation .....

https://www.windynation.com/Rectifier/35-Amp-3-Phase-Bridge-Rectifier/-/218?p=YzE9MjA=

You have to mount it on something to act as a heat sink and keep it cool, and make a little wire harness, but that's not hard. I used a chunk of heat sink from an old computer. Others have just used a piece of thick aluminum plate .....

 

[Sir Real Ed]

Thanks 5Twins. With my current (pun intended) level of knowledge I plan to go with the regulator and rectifier you recommend, and a chopper wiring harness from TC Bros., MIke's XS's, Hugh's Hand Built, XS Central, etc.

Any vendors out there that anyone would recommend above other? Any vendors to stay away from?

thanks in advance.

 

[5twins]

I actually saw one of those TC Bros. harnesses once. I burst out laughing. It's nothing more than like $2 worth of wire and they charge like $40 for it. As far as big rip-offs go, it's neck and neck with their shit engine stand, lol.

 

[Sir Real Ed]

if any of you get a chance, please measure from the centerline of the front axle to the top of the fork tube (without any weight on the front wheel) to determine the overall effective length of a stock XS 650 fork. On my 77, I have a 650 Seca Turbo fork, and on the 76 the fork appears stock, but I do not know if it has been shortened. On the rear of the 76 are some Redwing shocks, that I think are shorter than stock, hence my suspicion that the fork may have been shortened.

thanks.

 

[Sir Real Ed]

Can anyone identify what year XS this instrument cluster came from originally? thanks.

 

[gggGary]

74-75

 

[Sir Real Ed]

thanks Gary.

 

[Sir Real Ed]

Very little progress made to date, due to other priorities taking over. I did acquire a nice set of 34mm carbs and manifolds. The 38mm carbs I have, have the slides welded in place, and the diaphragms are shot. At some point, I will probably go with Kawasaki EX 500 carbs.

Messing around with the wheels, I found that my Suzuki DR 650 car axle is very close to the XS axle. The DR axle is 3mm shorter in length, both the 20mm diameter and the OAL. Threads are the same. A DR 650 rear wheel and caliper mount might be an easy swap. Of course chain alignment and wheel alignment are the main concerns, especially if the DR 650 caliper carrier is used.

This opens up more possibilities than I originally considered since I have a DR 650 and a set of SV 650 cast wheels that have been machined to fit the DR. I also have a set of Honda CBR 250 wheels that I once considered machining to fit the DR. So many options, so little time.

 

[Sir Real Ed]

Curious as to what types of switch gear you guys have used (with the goal of simplification/minimalist looking) who are not trying to restore their XS650's to original condition.

Quick thought, on my trials bike, I have a magnetic kill switch that is strapped to your wrist. Also known as a "Dead Man's Switch" in old hipster lingo. Noticing that my DR 650 uses a running closed kill switch as opposed to a running open normal XS kill switch...... Maybe I will use a magnetic kill switch as both a kill switch and an ignition on/off switch replacement.

Hmmm......
https://www.ebay.com/p/607761733?ii...MIztvQzqb36AIVg4CfCh0IxQQ8EAQYDSABEgLyrfD_BwE

 

[jetmechmarty]

Dime City has several options. Search “switches”. If you pockets have depth for this, the Motogadget stuff is extremely minimal. Revival Cycle has even more minimalist stuff in that category. 2 Fast Moto has some less expensive options as well.