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*Sigh*

It's really the other way around. When the ground isn't good where the coils and condensers mount, the condensers can't properly do their job of buffering the arcing at the points.
 
It was powder coated and I don't think they did a very good job of plugging holes.

This was the reading between the coil mount and one of the lower engine mount bolts.

IMG_0233.jpg

Seems a bit high, no? :D

It was roughly the same to the main ground on the downtube, but it jumped around a lot. From the negative battery terminal to the bolt on the main ground, it was about 0.3.
 
You can never rely on powdercoaters to keep all threads and ground surfaces clean. Always check and clean them, assume the least attentive behavior these days because it's more often than not true
 
Every threaded hole needs to be tapped to get clean, The engine mount points have to have the PC ground off to clean metal like this
RIMG0427.JPG
Use your VOM with one lead to the negative battery terminal and using the other one to test everything that should be grounded. Ideally there will be zero resistance every place you test, less than .1 ohm is ok. .1 ohm and higher means something isn't right.
If you recall your frame before the PC was done remember that unpainted grey strip right under the coil mount? It actually was painted with a conductive electrical paint to achieve a good ground there.
 
I checked several points of ground contact last night. The ground strap tested at 0.3. And I retested the coil bracket just to make sure that I was getting on the bracket. It settled at 22. Since I've made some minor modifications with a new horn mount, I had removed the stock mount (#7), which I'm sure contributed.

Wiring harness.jpg

I'm going to go back through on Saturday with the dremel and get some bare metal. The coil bracket doesn't quite fit the frame very well. It wobbles just a little bit. I wonder if there is some value in removing the PC, then covering the bare metal with a strip of conductive tape and then installing the bracket. That seems like it would prevent any corrosion issues.
 
Couldn't wait til Saturday and had a few minutes last night. I dremeled off the PC around the bolt holes under the coil bracket. Unfortunately, that didn't do much to help. It was still reading 20+ ohms. I think part of this is because it doesn't have a solid fit there, and I've made some modifications to use a different mount for the horn. So there just isn't tight/consistent contact between the coil mount and the frame. It's just going to wobble a little bit on the road, so I thought I'd better find another solution.

So I found an empty ground slot in the headlight bucket, ran a new ground wire through the harness to the coil mount. It's not ideal, but it's tidy and neat and it's now reading 0.3 ohms, along with everything else on the bike. I know this is higher than LDR recommended, but my VM is reading 0.3 from one end of a bolt to the other, so I can't see how it could get much better.
 
I was going to suggest a ground wire from somewhere else nearby, and the .3 reading you're getting could easily be from a bit of error in your VOM. Since you're getting a consistent reading everywhere now, you should be good
 
The .3 ohms resistance will be fine. It does however suggest that the ground wire for the harness may not be making a good connection with the frame. That one ring connection back at the battery/tool box mount.
I didn't like that there was only 1 frame ground connection so I added 2 more on mine.
 
Yeah, I need to grind off the PC with the main ground. It would seem that the engine mount bolt there is doing a pretty decent job, but a little wire-to-frame clean up can't hurt.

I tried to minimize the number of ground wires in the harness, but it's tough with all of the modifications. I know that some folks like a ground for each circuit, but that would have been a lot of effort on this harness. I am a bit concerned about the number of connectors. I think I ended up with one main ground to the headlight bucket, but I think are at least 8 connected to that wire. And I just don't have a lot of confidence in those 3-4 way female bullet connectors (or the males either for that matter). It was the easiest way to wire it for sure - just hope it holds up.
 
No need for individual grounds per circuit since there's no load involved, just a return path to the battery. I get a bit AR about grounds and other things at times. AR=anal retentive.
 
Well, y'all cross yer fingers and/or cover your ears. If this doesn't fix it, you're gonna hear me spitting expletives from FL to WA.
 
I took it for a quick test run last night. It started and idled pretty well - clearly both cylinders are firing now. Just a little bit of sparks between the right points. With the timing light, it looks like both cylinders are timed just a little advanced, but I think it's idling high (no tach). On the road, it was better, but still had some stumbling in the low rpm range. I guess now that I have it idling better, I can adjust the timing to dead on and see if that works better.
 
Dynamic timing and fuel mixtures have to be set at 1200 rpm. At 1300 rpm the advance weights could start advancing the timing due to weak springs(age) and the 2nd mixture port starts being uncovered negating the actual mixture adjustment.
BTW, there are rules about expletives. You cannot use the same word twice in the same day or you will owe 10 pushups per duplicate. Creativity in foul language is a requirement but since we don't post any of that you will be on the honor system.:lol:
 
I hooked the tach back up, adjusted the idle (must have been way too high before) and reset the timing both static and dynamic. It's damn near perfect. But the left side isn't firing. The plug has a nice big spark. And I tried adjusting the idle mixture with it running - no difference. So I pulled the carb off. It has a bowl full of fuel. The slide is working fine. There's nothing obviously wrong here. I'm stumped.
 
Remove the mixture screw and verify that the tip has not broken off in/blocking the passage from over-tightening.......
 
I pulled the carb apart and cleaned out the passages. The idle mixture passage is clear and the point looks fine. Also cleaned up the old jets and put those back in. It's blowing vapors out of the plug hole, and the plug is wet, so it's getting fuel. Checked the spark again - it's very good. What am I missing here? Could I have set the timing 180 out on one side?
 
Use WD40 and spray thru the mixture screw hole.You should see a good solid stream from all 3 holes, you can block the holes with a finger to get more volume. If that's good then look at your slow jet, the one under the rubber plug.
 
Ok. I'm going to start following y'alls advice to the T.

I took it for a ride yesterday - it's still not firing on the left side at idle. But it's behaving slightly better that before - still stumbling in the low-mid rpms and at a level throttle. Once it gets going, it pulls nicely.
 
Didn’t have time to pull the carbs off yet, but I did pull the air cleaners. I thought I would at least try to bench sync the carbs, which I didn’t even know was a thing. Followed CMC’s video (I know AD!!), and used a bit of mig welding wire. It seems that the idle adjustment screw isn’t long enough to open the butterfly on the left side. It just barely makes contact with the stop if it’s cranked down tight. That’s weird, right?! It works on the right side just fine.

I’m pretty sure that the cable is allowing it to close all of the way, but not completely sure. That’s a strong possibility because it’s a custom cable and it’s just barely(or maybe not) long enough. I mean, I don’t have a mm to spare. I’m thinking that I could maybe cut the top nut (at the carb ends) both cables and get a few mm’s of adjustment just to put a bit of slack into it. Otherwise, it’s ordering yet another custom length.
 
The problem with bench syncing separated carbs is it only works for the idle settings, which may be too far off one way or the other after installation and end up getting separately adjusted again anyway. Since they have individual cables to sync, it can't do a thing for anything but syncing idle, the cables still have to be manually synced.
 
Well, that was like herding cats. So I pulled off both carbs, replaced the aftermarket jets with the originals, which I cleaned up. I cleaned out all of the passages with carb cleaner and compressed air. Set the float height at 23mm, which is what the shop manual says. They were at 26mm. Then bench sync'd with a tiny piece of mig welding wire. Sync'd the cables. The first hit, it barreled straight to 5-6000 rpms. So the bench sync was crap - way too far open.

When both cylinders are hitting, the idle is too high. And it reacts pretty drastically to the slightest turn on the idle adjustment. So it's either got one cylinder not firing, or it's idling at 2K rpms. The mixture screw doesn't seem to make any difference at all. I think it's supposed to have a washer between the spring and o-ring, which I don't have, but I'm finding mixed messages on that all over the place. I *think* they're 3D - stock as far as I know. Here's an old pic:
RSH1nG4X--LGNkcLY208Laut5mb730FGiU7R8Mxi6b51kFReBOfWfhFhYssx9Rx6NnbVZzpOzM4kYCdOkY7dBPeed8Nvi8rKYvL4MmAwsOaYbk0DRDK-nsefibxKEFx78XfXS1BRXGset22n-qvbHPQJiV-1pMViRt_kWX3_FSm3h_-p-8018w5CosltngW30sqEDzZ3KFaiY2X04XopZKhG6_AIpz0w47FGm9TeHad4eyCNH-YKHDfKojM4eVgJXdFjnMUfJ-bMsyH5X5afvPPytZnzdAoexnnoFLCoL9s8IJn-qdFJVf_7rJOdsVf9oXdvUmM7QUiV9C3hcFrNVUR5idkF6wEnOykWWDa15LhYEfC7az3iS1Mf0t1cFeQ0nD4ipRqQKuL4aiwqL8XMONxW6xjrKgWRJoxjK_eKcnMuyxyuv7uvIPqqmecKohxtpDSFPa1gfQPaC7Z8TZ1A08nnF_xvru5LBrR4ZpDN19HhRMOXburuxKjQSa0XlWaW2ESkj8WUxxd-Yuh-FBWYL1Td_lA2Sx_z3h_-gT4VthQTYjhi2KzBSlYI1MvH0amwwjHcmUli2lzCpyzwDhfzyVd-L875bMRH3PQ8-IaIEOb7qHcsTMw-HnVQQF-l4ZRpvcuKxHyTB0RDkL8HLknbnx-WmiVnXVLYdzKu_lC294_-E9YIVjPeJzBXRBKW=w579-h772-no


So, it was like, 40 minutes of pretty random fiddling on both sides trying to find a very, very sweet spot, if it exists. That 40 minutes was punctuated by nearly spontaneous racing idles, hanging idles, and bogging down with a bit of throttle.
 
Picture doesn't show, might need to resize it to 2Mb or less.
You should have 3D carbs, they're marked. Float level for the 3D is 26mm, not 23mm. Even if you have the later 722A carbs the float level is the same.
Idle speed needs to be 1250 or less for the mixture screw to work.
 
Yes, they're 3D.

I guess I'm going back to the beginning today. Check the valve clearances, check the advance unit springs, reset the timing, reset the float bowl height.... what am I missing?
 
I haven’t. I’m not sure if I was aware that they existed. More research coming I guess.

I did all of the above, including swapping out the advance mech for the other one which felt like it didn’t have as much play on one side. I tightened that spring just a little bit. Got everything back together and got a decent idle. It still sputters a bit. And when I took it back out after lunch, it did that 3k rpm idle again. Shut it off and tried again and it did ok - lower than it should be but ok. Took it for a ride and the throttle hangs like crazy. Also there’s still a bit of bogging down from a neutral throttle but it gets going much better.
 
Man, the levels of my stupidity are astounding sometimes.

I popped out there just to take a look at the felt situation. They are intact on the backup carbs, so I'm pretty confident that they just need to be oiled on the installed carbs. That's a project for Saturday.

In the meantime, and here's where I get reaaallly stupid, thinking about how the throttle hung up so much on that last ride (5k rpms between shifts), I eventually concluded that the cables must have been stuck or crunched somewhere. I just confirmed it by twisting the throttle and it didn't roll back. I checked the cable, wiggled it around some and didn't see any issue. But the grip keeps sliding down the throttle tube just enough to reveal the tube and show a gap (so maybe .5"?). That was visually unacceptable, so I got the air hose yesterday and jammed that sucker back up the tube. Unfortunately, I must have pushed it too far and it was getting stuck against the throttle housing. Epic levels of simple and stupid, which really should be the name of my entire build.
 
Look at it this way - we all overlook something sometimes, and it's usually the simplest of things because that is never what you'd expect. And, it's another learning experience that turned out to be something so easily solved. I'd call it a win, myself. (y)
 
Updating. I disassembled the carbs and replaced a couple of the felts with homemade ones. And I also welded several patches on the upper exhaust. And I also had to fix a problem with the starter. The battery lead attaches to a bolt that has a soldered connection inside the housing. That connection had broken again, but I think I did a much better job of soldering it in place this time.

So overall, it's running pretty well. It's still bogging a bit at neutral throttle, but and it's a little bit boggy in the lower rpm range. I'm not sure what to look for there.

And the throttle is still sticking between shifts. I thought I had that fixed with the grip, but unfortunately, no. It seems to snap back into place when the bike isn't running, and doesn't seem to be doing it in neutral. It's a custom length MP cable that has almost zero free play in it. I don't think that any of my other cables have enough fp to work. But I'm thinking that the 1:2 junction might be getting stuck in between the motor mounts. Also not sure what else to look for with this situation.
 
You absolutely need some free play in the throttle cable or it's definitely going to stick.
My advice would be to get a new cable.
 
I've been thinking about that and I just don't quite understand it. When the current cable is fully adjusted "in" on both ends, there is just a little bit of slack in the cable between the stop and the throttle arm on the carb, which is how it's supposed to be right? I mean, if I had 5 or 10mm more free play, I would still be adjusting it to just a little bit of slack, right?
 
You would, given that turning the bars full left to full right doesn't affect that slack. It usually does though and routing has a lot to do with it. There is one more place you can gain a little slack. Where the roughly 90° elbow screws into the throttle/right switch housing, you can screw the elbow into the housing a little further, maybe from one to three turns more, and it will provide you with a little bit more slack length
 
I’ve done that already. All 3 points of adjustment are “in” all the way. The last option would be to cut off the top nut on the adjuster at the carbs to get just a few mm’s when the adjuster would go screw all the way to the mount and the lower nut would hold it in place.
The only other idea that I have is that the clutch cable is fouling the idle arm. It still snaps back ok, but I can feel a click on the way up and confirmed it’s the clutch cable. I don’t see how that can’t happen though. There doesn’t seem to be a way to secure it away from the idle arm.
 
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The curves in the cable can help remove slack as well, so to speak. If the curves are as sweeping and as gentle as possible, then the movement of the cable makes less of a difference in the position of what it operates. Did you tie the clutch cable on the frame under the tank to try to help keep it in position away from the left carb?
 
Had a few moments to check things over last night. First, the carb cables were not sync'd, which surprised me (but probably shouldn't - I mean, it's not like I haven't established a pattern of missing steps). Just something i forgot to check on the last (of many) re-installs. So I took care of that. Then lifted the tank to check on the cables. The throttle cable is routed properly. I thought it was between the motor mount, but it wasn't. However, the clutch cable was (why would I do that??). Re-routed that according to LDR's link. So the end result is that, at the moment, the clutch cable is now about an inch outside of the idle arm, which is good. But it's also the longer cable, so quite a bit of excess is sticking up behind the headlight. I have a shorter option for the clutch cable that I'll try next. I think that it's just barely long enough to work, but I last tried it when I was having all of those problems with the clutch a few months ago. It's the better option, if it works properly.

And as usual, *sigh*, pulling the sprocket cover off is a hassle with the CL pipes. This time, I reinstalled the pipe mounts and the swingarm nut before adjusting the clutch. Dumb move. Something isn't right with the clutch bearings, lifter, etc. I've done that disassembly, check, re-install about a hundred times now, so figuring that out shouldn't be a problem (nut/adjuster bolt/adjuster plate/bearing plate/lifter/ball bearing). But it means that I have to pull all the ancillary stuff off again. Just didn't have the energy to go back in last night.

I should probably take a cognitive test.
 
I replaced the clutch cable with the custom (very short) one and I like the routing on it much better. I think it still needs some adjustment to be perfect, but it's working pretty well. There was a LOT of sorting on Saturday - just a bunch of little things that needed attention.

On Sunday, I wrapped up pretty much everything to make it as good as possible and took it for a good, long test run. It's still acting up a bit, but this is the best that it's run so far. Unfortunately, I ended up on the side of the road again.

IMG_0244.jpg

At least this time, it was just gas. So Lil K came out in his pj's with a gas can and rescued me. Overall, it's working pretty well. It still hangs revs quite a bit between shifts and it still has that boggy throttle cruising along. And I sometimes have to force the revs down by braking in gear.

BRP trip this weekend, providing Sally doesn't wreck everything.
 
I got rid of the mirrors and replaced them with one 2" bar end. I was worried that it might be too small, but it's just perfect. And it fits the build so much better.

I did about 120 miles on the BRP on Saturday with my brother on his 78? R80 and Pop following along in the support SUV. It was pretty chilly - 50F and cloudy and we were both happy to sit in the car and warm up for a lunch break. It was a nice ride, but would've like to have been a bit warmer.

So I have a pretty significant oil leak coming from somewhere around the left side cam case. I can't tell if it's the cam case cover, the points case (I know this is a common leak point), cam case to head gasket, etc. It's enough flow to get the carb wet, and some signs of it hitting the exhaust. And it's all in fins of the head and jugs.

Also, I've decided that both the clutch and throttle cables need to be about an inch longer. I have 4 longer clutch cables, so I'll make one from those. But it looks like it's back to MP for a new throttle cable.

And finally, I've noticed that it smokes (white) quite a bit on some cold start ups, but not others. And I can't figure that out.

And finally, finally, I need to start thinking about how and where to sell it. It'll probably be the spring, but prices around here are pretty low right now. I have some resources that could put it in the SoCal market, where I think I could probably get about 20% more. Also, kinda thinking about BringATrailer, if I could get them interested.
 
White smoke is just water condensation so no worries there.
Best selling time for bikes starts @2 weeks after riding weather starts becoming good. High population areas tend to bring higher prices.
 
I checked behind the points cover last night and didn't notice much oil there at all. But I just pulled the cover off. There was quite a bit of oil around the fins behind the cam bearing, on the carb, on top of the crankcase on that side and on the pipes, so it seems like if it were the rocker pins o-rings or the cam bearing seal, I would have seen it in the cover, right?
 
Maybe, but not necessarily. The flat wahsers on the rocker shafts would seal most of the oil out of the cover but I'd imagine there'd be some seepage. Did you check the 4 screws on the cam bearing behind the advancer for tightness?
 
I did not, but I will. There was just a drop of oil in the cover. I remember being pretty careful about the orientation of the bearing gasket, but I think it's pretty well established that I'm not to be trusted about such things. Really don't want to have to take that bearing off... The top cover gasket and the cam case gaskets are both a bit wet, so it could be seeping out of there as well, but there's no obvious egress.
 
Did you use the JIS screws? If so, did you tighten them with a standard-style JIS screwdriver? In other words, not an impact driver or t-handle? It would be difficult to get enough torque on a standard handled screwdriver to get them tight enough.
 
I haven't even had time to open the shop door lately. But I did get in there briefly last night to swap out front fenders. I'm not sure which I like better.

Before
IMG_0250.jpg

After

IMG_0267.jpg

The CL fender is in much better shape and I prefer the overall weightiness(?) of it. But it definitely sits higher. The CB fender is pretty rough, but I could probably find one in better condition.

Ideally, I could find a way to close the gap between the tire and the CL fender.

Oh, and the wheel had to come off to get the CL fender on. While I was doing that, I found one of the nuts on the axle clamp loose. Yikes.
 
Yikes is right, good that you checked them. Pretty sure the CB front wheel is 18" and the CL has a 19" front wheel, which explains the bigger gap. The CL fender looks good and if it sat closer to the tire it would be my choice.
 
Yeah, I agree. So my options are:

- get a 19" wheel, which probably won't be easy and will definitely be expensive - new rim, spokes and tire.
- swap out the bracket - not sure how difficult that would be
- get a better CB fender and trim it
- fab the CL bracket lower?
- ?
 
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