STANDARD issue…. a resurrection begins….

Floats adjusted to 24mm and dropped the needles one notch to lean a little. Now just waiting for new o-rings from McMaster-Carr for the needle jets and these should be good to go at least for a base line start up. Mama Yama wants $7 each for those buggers before shipping. McMaster sells them for 4.75 for a 25 pack. Let me know if anyone needs a few. Also looks like the butterflies have been off before. I noticed one screw is a little different and they are not staked on back. Hoping that indicates the throttle shaft seals have been done before. Is there a way to check them without disassembly?
 
I just went back through this whole thread Rob, what a great story. You’ve really done a lot without breaking the bank and it ought to be a proper little ripper with that BBK motor and I love the addition of Phil’s handmade pipes! You’re getting close buddy, it won’t be long before we’re hearing brmmmm brmmmm noises! 😃 I do hope you’ll post a video of it!
 
Don’t tell anyone but I already make those sounds when nobody’s looking

You too? My little RD200 has been justa' screamin'.
sometimes the wife has to come out in the garage and tell me to shut it down. :laugh2:


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Yes, you can check the left seal on each carb by just removing the cable arm (left carb) or the sync bracket (right carb). Checking one should give you a general idea of how (hard) the rest are. With said bracket removed, you can carefully work the seal out and give it the "pinch" test. New (or good) ones are very soft and will pinch down to an oval shape very easily .....

NewSeal.jpg


Old, hard ones, not so much, lol .....

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If you've never used one before, I think you're gonna like the '78-'79 carb set. It was the last of the BS38s and I feel about the best. The needles are spring-loaded and that gives smoother low speed operation.

And if you want to tweak their performance, find yourself some 5Z1 needles from an XS400. These taper to a sharper point and give snappier off-the-line performance .....

5Z1 Needle.jpg


5Z1 NeedleTip.jpg


But, after that sharper point, they get fatter and leaner than the original 5O2, so you only want to use them combined with larger mains and pilots. You need the bleed-over into the midrange from these larger than stock jets to make it right. Also, you may not need to lean them a step. I'm playing around with a '78-'79 carb set with these needles at the moment on my '83. I started out with them jetted as I would with the original needle - one up on the pilots (#30), two up on the mains (#140), and the needles leaned a step. With the needles leaned a step, I encountered something I never have before, flat spots in the upper midrange. Normally I get break-up or "gurgling" because it's too rich. So, I richened the needles a half step with a shim washer and that almost cured the issue. Next, since it was easier than pulling the tank to get at the slides and needles again, I bumped the mains up another size to 142.5's. This seemed to do the trick and the bike runs really well. I'll have to put more miles on it to see how it does long term, and to check mileage. It's amazing what one jet size change can do sometimes. I've never run a main this big before but the bike seems to like it.
 
Minor update... new o-rings installed on needle jets and put back together nice and snug like it should be. Carbs installed with new boots that I picked up last winter from George's Fix. Went to install the airboxes and had a few minor hiccups. First I realized that my mount for my new voltage regulator was interfering with my left airbox. If you recall I had included a third rubber isolated mount so it was all secure. This third bolt was hitting the back of the airbox.
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The quick solution was to remove the bolt and the isolator "shaft". Then cut the isolator in half so the tunnel part of the isolator still protruded through my mount plate. This allowed me to keep the rubber isolator on back while sandwiching with the airbox. I'll remember to keep an eye on it down the road, but it feels very solid to me.
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One step forward, two steps back again. When I went to hook up my vent line to the airbox, I realized the metal vent tubes on the airbox had quite a bit of grease/rust/crud in them. That won't stand with fresh carbs! Back off they came for some cleaner and compressed air. After cleaning out and blowing little wads of paper shop towel through they were deemed clean enough to go on. Now I am working on throttle cable lubing and routing. Little victories, one at a time.
 
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I needed to circle back to my air filter that I repaired some time ago. The adhesive I had on hand did not hold up, so I had to redo it with some traditional JB Weld. It was a pretty straight forward repair. But I also made note that the weatherstrip was all shot too. So I picked up some thin 1/4” window weatherstrip at the local Farm and Fleet and it was a perfect size. I replaced it not only on the filters, but also on the air box access doors too. Now everything is looking nice and tidy and fitting snug as it should. I like these easy little jobs that I can knock out quickly.
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I’ve been avoiding todays task for a little while now. I’m no fan of wiring, so I’ve been gathering supplies and planning my diagram for a while now. With everything in place and diagram in hand, I spent the whole day patiently wiring. I started with a couple stock harnesses that I harvested wires from. I also bought some extra 16AWG wires, 1/4” and 1/2” split loom cord protector, cloth wiring tape, and a BlueSea fuse block with bus power terminal. I already had a stock supply of bullet connectors, crimper, stripper, and heat shrink on hand.

Components I am running are stock alternator, VR115 voltage regulator, Tytronic ignition with mechanical advance, stock coils, stock rectifier (for now), electric start, turn signals. I am also using the stock handlebar controls. My goal is a simplified harness without all the extra crap. The basis of my harness is from the Tech board. Once I have everything hooked up and confirmed working, I will update my diagram with full color and laminate it for my records.
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I started with the Rect/Reg wiring as it could be done at the kitchen table. I utilized factory connectors and made it a little longer than I meant to, but that’s ok for now. I have another I may make up once everything is confirmed running. I really like the cloth tape. It’s tears easy and isn’t gooey like regular electrical tape is.
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Once that was all in and installed I moved on to the fuse block. I really like the compact BlueSea unit. I wanted something with a bus power supply to reduce some wiring. After I bored out the mount holes a little, it was a perfect fit for the two threaded bosses on the top of the battery box. I think there was some relay here previously. I ran some zip ties through small pieces of fuel line and looped back around and attached to the frame to create some standoffs so I could temporarily run the wires to length. Once the wires were to length and connectors installed I cut the standoffs away to run the split loom. The split loom is great if I ever have to add anything to the harness. My last job I used solid loom and was much more difficult to work with. I should note that I ran continuity tests on all circuits before putting the loom on.
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So now the key switch and right handlebar wiring is ran up to the coil area. I’ve still got to finish hooking it up and tidying up the wrap. I also still need to run the turn signal wiring, neutral light, and ground wires on a separate run. So far there is no wiring in the headlight bucket at all. I’m in a good stopping place as I can attack the remaining pieces as time allows. The only thing I am still working out is the wiring of the starter safety relay. There are some color code discrepancies I am working out. I very happy with the progress, although I admit my soldering skills could use some more work!
 
If you recall some time back I had an issue with a snapped rotor bolt in my front hub. Well this turned into quite a shit storm. My buddy made a valiant effort to extract the broken bolt, but had serious issues due to the broken extractor in the hole. He ended up drilling it out, welding the hole shut and in the end when trying to re-drill the hole kept having issues with metal from the broken extractor. He has since given up on it as he has his hands full with many other issues of his own. A question for those who know better than I, since I am not running a speedo, can this hub be flipped over and ran backwards? I know the hub is not symmetrical but I should be able to run the speedo drive side (sans the speedo drive) on the right side so long as I can make space it correct, right?
 
If you recall some time back I had an issue with a snapped rotor bolt in my front hub. Well this turned into quite a shit storm. My buddy made a valiant effort to extract the broken bolt, but had serious issues due to the broken extractor in the hole. He ended up drilling it out, welding the hole shut and in the end when trying to re-drill the hole kept having issues with metal from the broken extractor. He has since given up on it as he has his hands full with many other issues of his own. A question for those who know better than I, since I am not running a speedo, can this hub be flipped over and ran backwards? I know the hub is not symmetrical but I should be able to run the speedo drive side (sans the speedo drive) on the right side so long as I can make space it correct, right?
Perhaps a picture of the hole
I have seen on internet people are drilling hardened material even --- with the type of drills used for concrete
Please google there is one link

 
I haven't taken posession back from him just yet, so I haven't seen what the end result looks like. Just checking on some of my options. This is a really nice wheel that I will figure out how to salvage. Worst case I can just find a left side caliper and run the brake on the left side and a cover over the right flange.
 
can this hub be flipped over and ran backwards? I know the hub is not symmetrical but I should be able to run the speedo drive side (sans the speedo drive) on the right side so long as I can make space it correct, right?
Never tried it, but I don't see why not.
 
I retrieved my wheel today, and he explained to me that he welded the hole up with silicon bronze rod I believe? The issue he hit was when he tried to re-drill the hole, his bit kept grabbing and wandering off center. He was using the rotor as his guide. Anyhow, this is what we have.
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I think at this point the easiest route may be to secure a left side caliper mount bracket and just switch sides. I have a nice billet cover that Beags made that I can cover the affected mount hole so it still looks nice and clean.
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I think this will be my easiest solution here so long as I can find a left side bracket.
 
Ever since I wrapped up my ‘75 build I’ve been on the prowl for another project. I decided that since I have so many leftover parts from the ‘75 that it would be best to secure another standard frame and use my leftover parts to build another. Finding a titled frame nearby on the cheap proved harder than I thought. But persistence paid off when I saw a FB Marketplace ad. It was a little farther away that I wanted, but still within reach. The ad read: 1976 Yamaha 650, no title, has key, motor turns free. $500.
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Since I don’t do social media, I asked my coworker to send them a message. A reply followed within the hour. A woman was listing it for her father, so she provided his phone number. The guy answered right away. He is retired and a part time scrapper (my industry). He had cleaned out a woman’s barn and the bike was in there. She told him it was her deceased husbands bike and had been parked there since 1987. The expired license plate indicated this was accurate. As part of their agreement for the clean out, she told him to take it. This guy was not into bikes, and only saw it as scrap value, so I knew he would negotiate on his price.

Today I made the 2 1/2hr drive with cash in pocket and hopes set high. This bike is FILTHY! Like it’s been sitting in a barn for 34 years. Inspection resulted in the following: exhaust- roached. Seat - toast. Fork seals blown, but no rust on tubes. Tank was a little crusty inside, but totally salvageable. The exterior is in good shape with no visible dings. Side cover also in good shape. A little rust on top of the left cover. Misc surface rust on frame. Motor- leaky head gasket and points covers. Plugs looked decent. Compression- left 90, right 100. I didn’t push it too much trying to get readings. Carb slides not stuck!

I dinged him on the exhaust and low compression. Used that as leverage in my offer. $350 and we were loading her up. Pictures to come… having a few phone issues and need to head to my daughters game. Will update more later tonight.
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Rob you should be ashamed of yourself! Good score!
 
Well I am No Machinist but have had the fortune to work at places with experts and magicians.
So with a mill or shop drill it is doable unless the Bronze is exceptionally hard.

I have drilled a lot with hand held machines on sheet metal.
The trick I use is to hold the machine in an angle towards the surface counteract the drift.
If it wants to drift 3 o clock you counteract that by leaning the machine so it drifts the other way.9 o clock
It can look strange but it works
If you do that at an early stage you can drift it back to center.
The hole wont be perpendicular but that does not matter since one starts in this case with a smaller drill
We used short 3.2 mm for Pop RIvets that dont bend so easy.

If that is a ca 10 mm hole the 3.2 or so is about a start and then larger. Again I dont know if the Bronze is hard.

Paying attention not getting out of center I would then eventually look into using ( what can it be called in English )
Tap and Die
https://en.wikipedia.org/wiki/Tap_and_die

The first one is conical at the point and goes in a slightly smaller hole. With care so it don't brake if so back out and drill more.

But why not talk to a machinist shop. I don't think it is a big job.. Would not be for the ones mentioned above
 
From researching here, I see the SR500, xs850 and xs1100 all utilize the same left hand caliper bracket. I’m on the lookout and ham PM’s out to the usual suspects with nice parts hoards.
 
From researching here, I see the SR500, xs850 and xs1100 all utilize the same left hand caliper bracket. I’m on the lookout and ham PM’s out to the usual suspects with nice parts hoards.
When I converted to dual disc, William ( @DogBunny ) let me know he had everything for the left. That was a few yrs ago but I'd guess he still has all of it.
 
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