Thanks for the feedback!
$90 with shipping, good night! Sounds like I need to go through the hoard of parts again very carefully before proceeding. Don't want a $90 repeat of the petcocks...
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You are blowing me away with the quality AND quantity of work you are doing Rhy!
The early bulb is kind of a morphodite. It's not a sealed beam, but has a crimped bonded reflector/lens surrounding a non removable dual element bulb.
The mounting points are integral to the reflector compared to the later standard sized sealed beam units that are sandwiched into two mounting frames. Think this was a DOT thing requiring a standard readily available size for easy replacement. The motorcycle bulb is lower wattage than the standard auto 7" sealed beams.
It's possible to replace the early bulb with a later style in the early ring with some skullduggery and W clips. I did this to get an LED light on WJL.
No parts out side of screws and washers are a direct interchange between early and later units
NOS (danged bogarters, wink)
Hope that helps a bit.
Dog gone it mm you had me doubting myself. Drum roll, yes they are quite differentThat’s funny, I never noticed the difference between my two bikes.
The early bulb is kind of a morphodite. It's not a sealed beam, but has a crimped bonded reflector/lens surrounding a non removable dual element bulb.
The mounting points are integral to the reflector compared to the later standard sized sealed beam units that are sandwiched into two mounting frames. Think this was a DOT thing requiring a standard readily available size for easy replacement. The motorcycle bulb is lower wattage than the standard auto 7" sealed beams.
It's possible to replace the early bulb with a later style in the early ring with some skullduggery and W clips. I did this to get an LED light on WJL.
No parts out side of screws and washers are a direct interchange between early and later units
NOS (danged bogarters, wink)
Hope that helps a bit.
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You made my night easier, haha. I pulled this up on my phone literally while staring at this jumble of lights.
Turns out I have two early and two late headlight assemblies. Both rings are damaged and the early bulb that works has broken mounting tabs 
In other news, I finished wiring it and had mixed results:
Overall, I am still very pleased with the outcome. I was expecting to see all the fuses blow and the battery explode, so the fact that most of the systems worked was a pleasant surprise. Many thanks especially to @Jim, @5twins, @Paul Sutton, @650Skull for helping me get this far. Regarding the bum starter, I went through all the connections and everything looks good (EDIT - I thought I checked all the connections). I think this leaves two possibilities: 1) A component (starter motor, relay, or solenoid) is broken or 2) Something is connected incorrectly. I did end up changing my diagram to accommodate my specific components and I think that is the logical place to start. Anyone see anything wrong with the starter wiring in this?
Any other thoughts?
In other news, I finished wiring it and had mixed results:
Overall, I am still very pleased with the outcome. I was expecting to see all the fuses blow and the battery explode, so the fact that most of the systems worked was a pleasant surprise. Many thanks especially to @Jim, @5twins, @Paul Sutton, @650Skull for helping me get this far. Regarding the bum starter, I went through all the connections and everything looks good (EDIT - I thought I checked all the connections). I think this leaves two possibilities: 1) A component (starter motor, relay, or solenoid) is broken or 2) Something is connected incorrectly. I did end up changing my diagram to accommodate my specific components and I think that is the logical place to start. Anyone see anything wrong with the starter wiring in this?
Any other thoughts?
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Re the starter: Must have missed it... what's it doing (not doing)?
Just thinkin' out loud.... the handlebars are rubber isolated and the starter button and horn both need grounds to work. I don't see a ground path on your diagram. Try temporarily grounding your bars and see what happens?
Just thinkin' out loud.... the handlebars are rubber isolated and the starter button and horn both need grounds to work. I don't see a ground path on your diagram. Try temporarily grounding your bars and see what happens?
Pushing the starter button had no effect in the video. I really hate to admit this... but when I was bending down to connect a ground wire from the handlebars to test your idea I spotted a missed connection. I had taped two ends of wire together, intending to connect them, but never did.
The good news - now everything works!!
The good news - now everything works!!
Don't you love it when it's an easy fix. 
This weekend I was able to get the wires all tied up. Had a great time doing this, a very pleasing task for those who enjoy organization:
The fuse box I ended up using was fantastic. It was so handy to have a central location to distribute power and the corresponding ground connections were also useful. That Li-Fe battery is ridiculous - so tiny and light, but it throws the crank around like a rag doll. I used this tape from Vintage Connections for most of the wrappings. I am a little concerned about it attracting dirt, but it is really nice stuff to work with and is freakishly strong. Thanks again to everyone who helped with the wiring, no way in hell I could have figured this out by myself.
Moving on... I did end up buying that headlight ring on eBay, had a hard time sitting down for awhile afterwards... As prominent as the headlight is using the beat up original one was just not an option. The lamp is also shot, but I realized that I might be able to just replace the headlight bulb. Anyone tried this on an early assembly like this? Perhaps upgrade to a brighter bulb in the process?
I have also started to think about the crankcase breather. The engine currently has a two hose outlet cover. I would like to replace that with a one outlet cover to cut down on tubing clutter. Any reason I can't do this? I couldn't really find why Yamaha had two versions of this. Lastly, I have some options for what to do with the outlet hose:
I believe that is a PCV reed valve from Mikes. Am I correct in thinking that I do not really need a filter if I use the valve? Should I expect much oil to drip from the valve? Any insights would be greatly appreciated!
The fuse box I ended up using was fantastic. It was so handy to have a central location to distribute power and the corresponding ground connections were also useful. That Li-Fe battery is ridiculous - so tiny and light, but it throws the crank around like a rag doll. I used this tape from Vintage Connections for most of the wrappings. I am a little concerned about it attracting dirt, but it is really nice stuff to work with and is freakishly strong. Thanks again to everyone who helped with the wiring, no way in hell I could have figured this out by myself.
Moving on... I did end up buying that headlight ring on eBay, had a hard time sitting down for awhile afterwards... As prominent as the headlight is using the beat up original one was just not an option. The lamp is also shot, but I realized that I might be able to just replace the headlight bulb. Anyone tried this on an early assembly like this? Perhaps upgrade to a brighter bulb in the process?
I have also started to think about the crankcase breather. The engine currently has a two hose outlet cover. I would like to replace that with a one outlet cover to cut down on tubing clutter. Any reason I can't do this? I couldn't really find why Yamaha had two versions of this. Lastly, I have some options for what to do with the outlet hose:
I believe that is a PCV reed valve from Mikes. Am I correct in thinking that I do not really need a filter if I use the valve? Should I expect much oil to drip from the valve? Any insights would be greatly appreciated!
A+ on your wiring! 
You are correct that you can get by with a single breather outlet, something I have considered myself for some time now. I have two hoses that vent out under the bike right in front of the swingarm and they do tend to belch oily vapor down there, which then turns into slimy crud. I have known others that just use a PCV valve and I guess it works, but I do wonder, what happens to the accumulated oil?
You are correct that you can get by with a single breather outlet, something I have considered myself for some time now. I have two hoses that vent out under the bike right in front of the swingarm and they do tend to belch oily vapor down there, which then turns into slimy crud. I have known others that just use a PCV valve and I guess it works, but I do wonder, what happens to the accumulated oil?
The valve needs to be higher than the breather outlet. That way the oil drains back into the crankcase.
We don't use PCV valves, they can't react fast enough to the engine pulses, we use power brake check valves, which are a form of reed valve I guess. The oil isn't past the valve, it's behind it in the hose, if there's any there at all. With a proper small outlet size, you don't get much oil or oil vapor coming out. This is something Yamaha changed and refined over the years. They started out on the early models with two outlets that had pretty big holes in them. They started getting complaints from some owners about too much oil vapor coming out. One of the first things they did was to reduce the recommended amount of oil to use. This lowered the level in the crankcase which apparently helped cut down on the oil mist problem. Then they started fooling with the breather outlets. First they blocked one off and only used the other one. Next, they went back to using both but stuck rubber reducer plugs in them to greatly reduce the outlet hole size. Finally they redesigned the housing with only one outlet pipe with a small hole in it.
I started looking at my carb situation last night and would really appreciate some feedback on my options. I know Dad originally intended to use BS34s, but if I recall correctly they didn't fit in the early frame. I have two sets of BS38s, one appears to be the '70-'75 variety and the other is the '76-'79. Both sets appear to be serviceable, but the early set is in a little better shape.
I hesitate to use the early set as I am a little turned off by the dodgy choke mechanism and non-linked throttle. A cursory glance suggest that parts for the later set might be easier to come by. Any opinions? What would you do? Thanks!
I hesitate to use the early set as I am a little turned off by the dodgy choke mechanism and non-linked throttle. A cursory glance suggest that parts for the later set might be easier to come by. Any opinions? What would you do? Thanks!
Theres two types 76-7 and preferred 78-9 intake bell the tell 78.9 has 5 holes 76.7 only 3
The float level on the later carbs was designed to be used with the later bent intake manifolds those intakes change where the carb inlets are in relation to early side covers, airfilters.
I have an early set of the Solex BS38’s on my XS2, and a linked set of BS38’s on my 77D. It’s not hard to find parts for either set. There are pros and cons to both.
The Solex,
Pros...
Not being linked can give you a little better feel of what each carburetor is doing independently of the other, you can use your fingers to blip the throttle linkage and fine tune the balance.
Not being linked makes it a little easier to install and remove from the bike.
No worries about the choke set up, it works just fine, it’s just different.
Cons...
Two separate throttle cables need to be synced
Plastic elbows for a fuel balance hose are brittle and hard to come by, this can be worked around.
A little more fiddly to tune, no vacuum ports for a manometer.
The later version linked set of BS38’s
Pros....
The linked throttle and single throttle cable are just easier
The built in vacuum ports make it easy to balance the carbs
No fragile plastic parts
Cons...
Not much really, about the only thing I can think of is not being able to manipulate the right side carb independently of the other when you’re working on the bike.
I can’t remember what exactly, but there is a difference in the carburetor mounts. Edit: I see Gary already covered that.
Thanks, guys! Sounds like I need to put on my side covers first and make sure that they fit with the later carbs. Didn't cross my mind to check that fitment. So glad I asked, if I went to the trouble of rebuilding the wrong set... I remember how pissed Dad was when he made that discovery with the BS34s!
Great information, just what I was looking for!
We stuck late model intakes and carbs on JRP1's 74 took a little levering but got them to stay on the stock filters, no one's the wiser.
Looks like I have a '78-79 set of BS38s - 5 holes. They fit, just barely... side cover fitment looks good. I found a pair of rebuild kits for these in Dad's shop and took that as the final sign.
Now I just need to make them look (and function) like this... Berryman's B-12 here I come
Now I just need to make them look (and function) like this... Berryman's B-12 here I come
