My rebuild journey. (old title: Future owner - Help me identify this 650.)

[650Skull]

pretty much every thing has been said...........80G SII frame visually, (tins/rear guard), is the same as the 78SE/79SF/79SII but the real difference is the swing arm and rear wheel.

NOTE; 79SII and the 80G SII have spoke wheels with a drum brake so he swing-arm has different brackets to accommodate the change from the disk brake to drum brake.................The 78/79 swing arm has brackets at the rear of the swig-arm that are removable so the axle can slide out of the swing arm from the rear. 80 and later swing-arms are solid so the axle has to slide out from the side.

NOTE; This may not be true for the 80G/SII swing-arm as per your pics
Edit;......Looking at your new pics your swing arm has the brackets that are removable so the axle, along with the wheel, can be removed from the rear of the swing arm, once the chain has been broken if it has the chain link that can be removed.

Can see what i mean about the early swing-arms, up to 80, here
http://www.xs650.com/threads/rear-brake-conversion-drum-to-disk-or-disk-to-drum.51944/

Mikes XS sells the 80G/SII wiring loom. 650Direct, (in Canada), also sell the same one and they both reference the same #no so it should be good to use without any mods. No guarantee about any mods but they shouldn't be to much and you don't have to worry about bypassing relays that are on the 81-84 models
MikesXS https://www.mikesxs.net/yamaha-xs650-wire-loom-80g-sp-ii-3g0-82590-50-oem-3g0-82590-50.html
650 Direct https://www.xs650direct.com/products?make=22&year=16&model=105&category=144

Having an 81 motor doesn't change a thing from having an 80 motor, They both have Factory TCI ignitions and the wiring on the igniter should be the same 6 pin coupling with the same colour wires


Vin no at the top of the chart




Post #4 i posted pics, for reference,of the 79SII and 80G/SII

 

[member28833]

If I were to be on the lookout for a back wheel. What should I be looking for?

Search out key words such as this-
80, Special II rear wheel. 36 spoke, drum brake, (assuming you want to stick with a drum) 16" chrome steel.
Do you have a swingarm for a rear disc brake or drum brake ?

 

[5twins]

My buddy's '80 SPII has the removable stops on the swingarm for the chain adjusters. As far as I know, it's original, so i think the '80 SPII did come with that feature.

As far as a rear wheel goes, any drum brake 650 one will fit. You'll need to decide whether you want an 18" or 16" wheel. The 16" was stock on the bike. I always leaned toward the 18" wheel because everything I'd read said it handled better, but after trying a 16", it seems to ride and handle just fine. I actually think it looks better on a Special too. It goes better with the "look" Yamaha was trying to achieve with the more angled shocks, seat, and side covers. I was going to convert my 16" to an 18" but the recent discovery of dirt cheap stainless spokes for it from XS650Direct (only $35) has made me change my tune, lol. I'm going to keep it.

 

[member28833]

Its obvious that Sudonate91's XS is equipped with a front 36 spoke chrome steel rim. Other pics do show that the swingarm and brake pedal are correct for the rear drum style wheel.

A matching rear chrome steel 36 spoke drum brake wheel (16") would be the easiest and best matching wheel to source.
Such as an 80 Special II rear wheel.

 

[650Skull]

80G SII and 81H SII, rear wheel are chromed rim, 16" wheel, 36 spoke Hub

80G..............................................81H

.

 

[Sudonate91]

Oh wow thanks for all the great information! Some reason I didnt get email alerts with all these posts!

I think Im going to try to take the carb off this weekend and see how it looks.

 

[Sudonate91]

https://www.ebay.com/itm/1981-Yamah...1-rear-wheel-rim-16in-w-sprocket/352803983049 -Just so happen to have a 16" wheel on ebay with the sprocket! Is $200 + $32.00 shipping a fair price?

 

[5twins]

I don't think so and besides, it's not complete. It's missing the combo spacer/dust cover on the sprocket side .....

Keep shopping, I think you can do better. Check your local Craigslist as well. 650 parts come up from time to time. The ultimate score would be a parts bike. You can often get them very cheap because they've either been wrecked, had the motor break down, have no paper work, or a combination of these. Because keep in mind that besides the wheel, you're going to need the brake plate, axle, and spacers, maybe chain adjusters too. Besides the left side spacer missing from the wheel in your link, there's also a spacer on the right side .....

Also keep in mind that pretty much any wheel you find will probably need new spokes to look really good. The one in your link certainly does, they're all rusty. So you have to figure maybe needing to put another $100 or so into the wheel to make it nice. That's why I don't like to pay much for them, maybe $30 to $50 at most.

 

[5twins]

I also wanted to mention your carbs. It looks like you have an '81 set there (probably came with the motor). The "tells" are the push rod operated choke, unpainted bodies, and the drain screw on the lower side of the float bowl. '82 and latter carbs were painted black and had a cable operated choke. '80 carbs had a different style of float bowl with a drain bolt on the bottom instead of that screw .....

When you take them apart, you should also find black plastic floats in there. The '80 carbs used old fashioned brass type floats. They can and do go bad, springing leaks and needing replacement. The plastic floats, on the other hand, are much better and practically indestructible. They're a solid plastic foam so they can't spring a leak. I mentioned in the post about the manuals needing a later manual to get the proper setting spec. It seems that even though Yamaha started using the plastic floats in '81, they didn't update the setting spec in the manuals until that SJ-K manual came out. The H supplement still lists the 27.3mm spec which was for the brass floats. The plastic floats, due to their different shape, get set around 22mm .....

There's also been speculation as to exactly where on the plastic floats you measure to, due to their different shape. This pic from a Suzuki shop manual seems to put that issue to rest .....

 

[member28833]

Just so happens that 2 days ago I came upon a set of 78/79 BS38'S which do seem to be very original, not too dirty, and quite usable if that should come up as an option.

 

[Sudonate91]

Just so happens that 2 days ago I came upon a set of 78/79 BS38'S which do seem to be very original, not too dirty, and quite usable if that should come up as an option.
View attachment 180328

How much would you ask for something like that? I am also getting an ultrasonic cleaner so dirty should be an issue

 

[Sudonate91]

I also wanted to mention your carbs. It looks like you have an '81 set there (probably came with the motor). The "tells" are the push rod operated choke, unpainted bodies, and the drain screw on the lower side of the float bowl. '82 and latter carbs were painted black and had a cable operated choke. '80 carbs had a different style of float bowl with a drain bolt on the bottom instead of that screw .....

When you take them apart, you should also find black plastic floats in there. The '80 carbs used old fashioned brass type floats. They can and do go bad, springing leaks and needing replacement. The plastic floats, on the other hand, are much better and practically indestructible. They're a solid plastic foam so they can't spring a leak. I mentioned in the post about the manuals needing a later manual to get the proper setting spec. It seems that even though Yamaha started using the plastic floats in '81, they didn't update the setting spec in the manuals until that SJ-K manual came out. The H supplement still lists the 27.3mm spec which was for the brass floats. The plastic floats, due to their different shape, get set around 22mm .....

There's also been speculation as to exactly where on the plastic floats you measure to, due to their different shape. This pic from a Suzuki shop manual seems to put that issue to rest .....

Incredibly resourceful. Thank you!

 

[Sudonate91]

The thing the old man said I would need was "a new carb". The son told me it ran rough. Im not sure if that implies its not repairable or not or just needs cleaning and tuning.

 

[member28833]

How much would you ask for something like that? I am also getting an ultrasonic cleaner so dirty should be an issue

Study carbs a bit and decide how you want to go.. I'm at work and in a machine currently busy. PM message me anytime to discuss a very cheap price on the carbs.
-RT

 

[5twins]

If you can save the BS34's, I would. They're actually a bit better and more modern carb than the BS38's. Properly cleaned and rebuilt, they work quite well. They used to be looked down upon because of their lack of an adjustable needle and all the E.P.A. mandated pollution controls (lean jetting specs) but that can all be remedied now. Parts for them are also more readily available and cheaper than the BS38 stuff.

Unless there are physically broken parts on them, like tabs off the bodies, you should be able to renovate them.

 

[Sudonate91]

If you can save the BS34's, I would. They're actually a bit better and more modern carb than the BS38's. Properly cleaned and rebuilt, they work quite well. They used to be looked down upon because of their lack of an adjustable needle and all the E.P.A. mandated pollution controls (lean jetting specs) but that can all be remedied now. Parts for them are also more readily available and cheaper than the BS38 stuff.

Unless there are physically broken parts on them, like tabs off the bodies, you should be able to renovate them.

Great to hear. I might actually work on getting the carbs off and on my bench tonight!

 

[Mailman]

By the way, I’m not sure of your past experience regarding cleaning carbs, so I’m just going to put this out there.
The ultrasonic cleaner is great for getting the outsides of the carburetors clean, but won’t be of much help cleaning all the small jets, passageways and orifices clean. My technique for that, stolen from @5twins , is to use a carburetor spray cleaner ( my favorite is Barrymans B-12 chemtool ) you can get that little spray straw right into all the openings, followed by a shot of WD-40 to keep anything that might’ve been melted by the carburetor spray from setting back up, then followed up with blowing out all the openings with compressed air. Works like a charm.
By the way if you’ve never sprayed carb cleaner through a carb body, you can be surprised by where some openings exit from. I have inadvertently sprayed myself right in the face before!
I always wear a full face shield.

 

[Jan_P]

I also believe it is a High price for the wheel .. a cast wheel appears to be cheaper
I would not replace the carburetors at this point in time
There are wiring and brakes wheels and so before.
Perhaps I have been lucky but I have had bikes in a shape that many here would not accept
1980 models.
Not had tight air filters .And even in that situation had little ..virtually none problems with carburetors.
A couple of times flooding But .With cleaning and the right jetting Which can be an art in itself .. . Not much more .I feel that the bike will run.
Perhaps not perfect but start and run.
My problems in 35 years has been the electrical side. Not engine ,, Nor carburetors ---Changing oil with common sense
And a bit of warm up before opening up. I believe it is difficult to trash these engines.
The bottom has a solid reputation and a top job Cylinder and pistons -Why not after 40 years and 30 - 50000 miles
A normal wear a gasket now and then That is part of the hobby.

 

[Sudonate91]

I also believe it is a High price for the wheel .. a cast wheel appears to be cheaper
I would not replace the carburetors at this point in time
There are wiring and brakes wheels and so before.
Perhaps I have been lucky but I have had bikes in a shape that many here would not accept
1980 models.
Not had tight air filters .And even in that situation had little ..virtually none problems with carburetors.
A couple of times flooding But .With cleaning and the right jetting Which can be an art in itself .. . Not much more .I feel that the bike will run.
Perhaps not perfect but start and run.
My problems in 35 years has been the electrical side. Not engine ,, Nor carburetors ---Changing oil with common sense
And a bit of warm up before opening up. I believe it is difficult to trash these engines.
The bottom has a solid reputation and a top job Cylinder and pistons -Why not after 40 years and 30 - 50000 miles
A normal wear a gasket now and then That is part of the hobby.

This is encouraging. If i can get it to run - I am prepared to spend a good amount of time and assets getting to beautiful again.

 

[Sudonate91]

Got the carb off!

I added photos of the tear down process to my album.
https://photos.app.goo.gl/apRrYDuJB16yrt3SA

Ill take the carb apart tonight and add more