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Frame clamps showed up yesterday, but today I had to put some hours into the '77 XS750 instead. Replaced the regulator / rectifier and verified that it is now charging the battery. Replaced all the brake lines with custom HEL braided stainless, and pads Vesrah semi-metallic, and it actually stops with some authority now. Just need to sort out the slow-ish leak in the rear tire, rebuild the carbs, and then it should be good to just pile miles on. No progress on the CB in the last little while. I'll probably do some work on it this week. It needs: 1) Bushings for the lower sidecar-side mounts 2) Fasteners for the motorcycle side of the upper mounts 3) Charging system troubleshot 4) Carb ultra-rich situation troubleshot And then it's on the road. Pretty exciting.
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Apr 25, 2016 03:12
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Took apart the CB400F carb rack, since I broke one of the pilot screws. Successfully used a left-hand bit and extractor to remove it. Double-checked float height and re-bench-synced the slides. Re-assembled and fired it up on the aux tank. It's less rich than it was, but still ultra rich, and after playing with the pilots a bit, it won't run now! Plugs are pitch black, but still sparking. Have a new set to try. gently caress. Got the carbs and petcocks rebuilt on the XS750. It's running super super lean, so I replaced the vacuum lines, and replaced the fuel lines with clear ones. Nothing flowing unless petcocks are on prime, but it runs alright with full float bowls. Took everything back apart to double-check, and it looks like the petcocks rebuild kits aren't quite right - there's no way to subject them to enough vacuum to pull the plunger off of its seat - the O-ring is too big, or the plunger is too long? Anyway, hell with it, I'm converting them to manual petcocks. loving carbs. 
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May 9, 2016 00:07
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Sounds like swapping the carbs from one bike to the other will fix both problems 
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May 9, 2016 07:14
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Slavvy posted:Sounds like swapping the carbs from one bike to the other will fix both problems Sounds like! Turns out the rebuilt petcocks didn't flow any fuel. I converted them to manual with some JB Weld and gasket maker, reinstalled them and the XS runs like a dream! Nice 1k RPM idle, smooth as butter at 3k5-5k5 RPM, and just from a bench sync. I'll do a vacuum sync this weekend, when I install the USB power adapter &c for the trip. No such luck with the CB. Have to tear back into it this weekend. 
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May 12, 2016 03:40
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sofullofhate posted:loving carbs. Tell me about it. You know what can kiss my rear end? Float heights. I love how the shop manual will say "set float heights to 9.1mm" but then to measure it you more or less eyeball it with a caliper or gauge.
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May 13, 2016 15:56
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Gorson posted:Tell me about it. You know what can kiss my rear end? Float heights. I love how the shop manual will say "set float heights to 9.1mm" but then to measure it you more or less eyeball it with a caliper or gauge. The transparent tube method is so superior but they don't always have a spec for that
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May 13, 2016 21:55
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Slavvy posted:The transparent tube method is so superior but they don't always have a spec for that Holy hell had no idea that was a thing had to look it up. Can't find specs for my Hawk though. I need another single carb thumper. Need to rejet or shim the needle? Loosen band on the manifold, spin the carb around.
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May 14, 2016 01:22
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XS750 is running on two cylinders today.
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May 14, 2016 02:46
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sofullofhate posted:XS750 is running on two cylinders today. Three now, with fresh plugs, caps, wires, and the electronic ignition installed. #3 is not running right though. Header isn't nearly as hot as #1 and #2, and the plug is a little wet when I pull it. I think I might have burned a valve or something :/
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May 15, 2016 01:28
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sofullofhate posted:Three now, with fresh plugs, caps, wires, and the electronic ignition installed. Time to compression test and double check clearances!
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May 15, 2016 05:25
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Slavvy posted:Time to compression test and double check clearances! Yeah
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May 15, 2016 06:10
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sofullofhate threadshitting on the Show Us Your Ride thread posted:Thanks, yeah, I agree - the butterfly seals are on everybody's "do this if poo poo isn't working" list. So, the Gen1 XS carbs don't have choke flaps - they have enrichment circuits instead. The carbs are bench-synched to the very best of my ability - butterflies are all in sync, the closed-throttle position of all three CV slides are the same. Floats move extremely freely and were already close to spec, but I adjusted them; float valve, needle valves, etc. are all brand-new from the rebuild kit. Main needles are all clipped on the middle detent. When I tore them down, I had them dipped in an ultrasonic bath and had the carb guy at my local vintage bike shop manually clean them too. The CV slide boots are pretty pliable still, no tears or holes, a few light vertical scratches on slides themselves, but I am unable to feel any resistance moving them around (and they're about $90 to replace).... hmm. After I check the valve clearance, maybe I'll try swapping one of the slides from one carb to the other and see if the problem follows. This evening I: * Played with the ignition timing on #3; no difference. Ended up advancing the overall timing and the bike is much happier though * Removed the enrichment circuit on #3; plunger spring is strong, seal looked a little suspicious but I checked it for seal against vacuum (with my mouth  ) and it held* Ran the engine with the enrichment circuit off; the #3 appeared to be drawing a healthy vacuum * Put a vacuum gauge on #1 and #3; they seem to pull about the same, but bouncing all the gently caress over the place so tough to be sure. I think pulling the same vacuum as a known-good cylinder is a good sign about piston ring health, right? And at least about exhaust valve health. Could still have an intake valve issue, but I'd expect to have backfiring if the intake valve were hanging open * Adjusted the cam chain tensioner, which seemed to be reasonably adjusted anyway * Said "gently caress it", and pulled the valve cover. Did I save the VCG? * Cleaned the inside of the valve cover, and inspected the cams  It looks shockingly clean in there. No evidence of bad lobes, scoring, pitting, or anything. I'm letting it sit overnight to get stone cold before checking clearances, of course. I guess I'm overnighting a loving VCG so that I can actually have some time to continue diagnosing things when this turns out to be another dead end. And, I mean, poo poo. If it isn't, how the gently caress am I going to get shims for this thing in any kind of reasonable time?
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May 20, 2016 05:51
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Fun facts: The shim removal tool for this bike is available on Amazon for $11. Valve cover gaskets for it seem to be everywhere. A compression tester with 10, 12, 14, and 18mm adapters is $35 on Amazon. Individual shims for the bike are $10. And in the UK, as far as I can tell.
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May 20, 2016 06:07
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Shims should be shared across multiple bikes - for example, KTM shims are very expensive but as it turns out they're the same as Harley shims! Woo!
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May 20, 2016 07:47
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Z3n posted:Shims should be shared across multiple bikes - for example, KTM shims are very expensive but as it turns out they're the same as Harley shims! Woo! They're 29mm - quite rare, from what I can find. Even generic kits are $160 for 20 shims. 
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May 20, 2016 15:49
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You can buy just what you need from places like this: https://www.z1enterprises.com/store/category/kawasaki/engine-parts/shims/29mm-shims (If they're actually 29mm and not some dumb thing like 29.25 or some crap)
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May 20, 2016 17:42
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I think I have some leftover shims from my YX600, let me know what sizes you need and we'll see if I have 'em. Or I can just track them down and send 'em to you. Guess I only had two:    Shoot me your mailing address if those will help. Skier fucked around with this message at 19:06 on May 20, 2016 |
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May 20, 2016 18:52
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Z3n posted:You can buy just what you need from places like this: Skier posted:I think I have some leftover shims from my YX600, let me know what sizes you need and we'll see if I have 'em. Or I can just track them down and send 'em to you. Thanks, guys  I'll check the clearances tonight and figure out what I need. I'll call around to local places first, and if no luck / 2.6mm is what I need I'll ping you, Skier. Or order from Z1 and pay $everything for shipping. 
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May 20, 2016 20:49
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Hilariously, those are exactly the size shims I need - but I found them locally. KLRs also take 29mm shims (yay). But - no smoking gun in the valve clearances #1 exhaust was pretty tight, but all intake valves were uniformly tight, and #2 / #3 exhaust valves were in spec.  Also: the loving VCG package was signature required. I heard the USPS dude pull up when I was in the garage, but I guess he knocked rather than ringing the bell, so I didn't realize I needed to sign for it. Now I won't have it until Monday. Goddammit.
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May 21, 2016 20:07
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Target clearances: int .16-.20mm exh .2-.25mm Pre-adjustment clearances (int / exh): #1 - .127 / .152 (yikes!) #2 - .127 / .229 #3 - .127 / .205 Post-adjustment clearances (int / exh): #1 - .18 / .229 #2 - .16 / .229 #3 - .18 / .203 Target hot cylinder pressure: 128 >= x >= 156 psi Cold peak cylinder pressure: #1 - 140psi #2 - 125psi #3 - 130psi No VCG == no ability to warm up engine. These pressures cold tell me that the rings and valves are healthy. Didn't think to do this before adjusting valves, so no before / after. Don't think these small adjustments will have really made a difference though. Back to the motherfucking drawing board. Weak coil, maybe?
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May 21, 2016 23:06
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sofullofhate posted:
Could be. Yours has a separate coil for each cylinder right? Should be pretty easy to move them around then and see if the problem follows.
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May 21, 2016 23:30
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Ola posted:Could be. Yours has a separate coil for each cylinder right? Should be pretty easy to move them around then and see if the problem follows. I tried the parts-swap game earlier in this process, and I'm pretty sure that the coil currently on the #3 came from the #1. Not much to lose by trying it again, I suppose. In CB400F news, new plugs, advanced the timing, and adjusted the idle mixture and it kind of idles without pouring black smoke now? Revving it results in billows of grey smoke - better than the awful black poo poo from before. Progress, I think. e: holy gently caress, the mounting bolts for the #3 coil were only finger-tight (aka lovely ground for that coil). That might be really good news. HandlingByJebus fucked around with this message at 23:53 on May 21, 2016 |
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May 21, 2016 23:51
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Status update:  Got the VCG today, installed this evening, buttoned everything up. No change; no surprise. Decided to play the parts-swap game with CV slides. Pulled the #3 slide... and the needle stayed put in the bore. loving circlip failed! Fortunately it was still in the slide rather than having been ingested by the engine. Replaced it with one of the originals, put it back together, pressed the starter and it fired right up to a steady 3-cyl purr. Took it for a blast. God drat that's quick for a '77! I can say for certain that it wasn't running well when I bought it. I am pretty happy right now. 
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May 24, 2016 04:21
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Brilliant! I demand video.
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May 24, 2016 04:58
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Slavvy posted:Brilliant! I demand video.
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May 24, 2016 12:59
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sofullofhate posted:Status update: That's loving awesome, glad it turned out to be something so simple. CA demands a ride-by video!
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May 26, 2016 14:01
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I'll get a video of it survives this trip 350 miles in: it's losing power up extended hills. If I drop from fifth to third and whack the throttle, it will liven right up and I can run through the gears. Seems like steady effort at ~same RPM is causing the power drop. It's not crackling like a lean situation when this happens. Anybody have any ideas?
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May 27, 2016 00:31
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Float levels, leaking diaphragms or a vacuum leak somewhere would be my guess.
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May 27, 2016 00:44
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Slavvy posted:Float levels, leaking diaphragms or a vacuum leak somewhere would be my guess. Hmm. I can't understand how float levels could cause this. Too low leading to starvation under heavy load? Too high and ultra rich in same scenario? Another data point is that modulating the throttle keeps this from happening for long periods of time. I did about 60 miles of steady climbing without experiencing this issue right after posting, by playing with the throttle constantly. I brought the butterfly seals and all the tools I need to install them, so I may actually tear them down at the campsite in Moab this weekend  to see if that helps.
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May 27, 2016 04:08
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sofullofhate posted:Hmm. I can't understand how float levels could cause this. Too low leading to starvation under heavy load? Too high and ultra rich in same scenario? Another data point is that modulating the throttle keeps this from happening for long periods of time. I did about 60 miles of steady climbing without experiencing this issue right after posting, by playing with the throttle constantly. If the floats are adjusted so at small throttle openings the floats don't allow enough gas, eventually the bike goes lean as it's taking more gas than it gets. If you modulate the throttle you avoid the problem because the floats are never at the point where they're not flowing enough gas, and everything is fine. That's my internet diagnosis.
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May 27, 2016 09:03
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It's the #3 specifically, I determined today. Pulled the #3 plug lead while it was happening, no change. It's the only hole with an old spark plug in it right now (because I fouled the replacement while trying to track down the carb issue), and I hear crackling in my headphones (phone is charging from USB on the bike), so I'm suspecting ignition. May be overheating an old plug. May be overheating the coil. The oil leak isn't getting worse, but drat it's messy. Going to hit a powers ports shop and swap in a new plug as a cheap diagnostic measure.
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May 27, 2016 18:32
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Salt Lake City!  Teardown-looking oil leak 
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May 27, 2016 20:53
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  Developed a nasty rod knock heading up the hill out of Spanish Fork. It will be going home on a UHaul trailer after I finish the trip on a rental bike.
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May 28, 2016 01:54
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Happy rebuilds!
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May 28, 2016 03:26
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e: ok so it's two for one day on the forums or something
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May 28, 2016 03:26
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Slavvy posted:Happy rebuilds! It's the hap-happiest time... of the year! 
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May 29, 2016 19:28
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https://www.youtube.com/watch?v=D5RHqD-Vn4M Diagnosis confirmed. That'll be a rebuild. At least it still has good compression across the board, this is strictly a bottom end issue. But since I have to pull the cylinders anyway to fix that oil leak, I guess I'm probably going to do an overbore... because why the gently caress not, right? See how nicely it's running otherwise? I'm pretty proud of that.
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Jun 3, 2016 21:05
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Put the Monster most of the way back together so I have something to ride for the summer. Streetfighter stacked projector housing is en route, I'm going to ride it without a headlight for a week or so until it arrives. Yes, those are the signals that are ziptied to the handlebars. Yes, the electronic dash is also ziptied to the handlebars. This is temporary, you understand. And in the winter, it's coming back apart for the turbocharger. God dammit.  Next: try to source the big rubber bits for the CB400F's stock airbox. The mechanic in Spanish Fork, UT who stored the XS for me there said he'd seen the exact same behaviour from another CB400F (that was actually at the shop when I was) with pods. Going to revert the breathing to stock and see if it fixes the mixture.
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Jun 13, 2016 01:15
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Lots of progress this weekend! CB400F   That's right, motherfuckers: I rode it! With the sidecar! ...it was terrifying. Turns out that the braces that came with it are all rubber mounted, so they don't provide a lot of stability, so my whole mount design is flawed. Major bummer. It was also really bad because, apparently, I didn't bother to inflate the sidecar's tire. So that was bad. I converted it from pods back to the stock airbox. I had to use layered duct tape for one of the rubber gaskets that disintegrated when I disassembled it originally, but it seems to be fine. It is running much better, but still smoking like hell. We'll see how it goes. But I rode it! With the sidecar! Monster Here I am installing the clamps for the new headlights:  Yeah. They're one-piece fork clamps, so I had to drop the loving forks to install them. I was... unimpressed. Also: I guess to save costs, the fork tubes don't have the machining marks polished off of them. That makes them not slip out of the clamps - I had to use a rubber mallet to hammer the fuckers out. And then I had to use a ratchet strap to compress them back up into the triples after I slid the new headlight mount clamps on!  But:   I think it looks pretty badass. Took it for a test ride tonight and even with the cheap Chinesium bulbs they came with, these projectors are incredibly better headlights than the stockers. Can't wait to get some real bulbs in there. Fun detail: because the headlight kit was generic, there was a tonne of space between the frame and the projectors. I had to fabricate some spacers for the mount, and I decided to use brass. If you zoom in on the photos you can see them, and I think they look pretty rad with the black mounts and the stainless socket cap screws. I also installed LED signals and resistors that I'd had lying around waiting for awhile. I'm also really happy with the carbon fibre front fender. Needs carbon tank covers to complete the look. Next: fabricate a mount for the display / computer. It is currently ziptied to the handlebar mount.
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Jun 20, 2016 07:35
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I've never seen an USD fork that didn't still have the machining marks. I thought that was intentional because it's part of The Look or w/e?
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Jun 20, 2016 08:15
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