1964 Honda Dream CA78 Rebuild-storationSwingarm CrazinessOkay so The Dream's been ridden 103 miles since the rebuild. Each mile has been trouble free aside from the minor oil seepage which seems to have been solved. Today we rode to the SoCal Cycle Swap Meet (better people-watching than at Wal*Mart), and after returning home, I noticed this as I was pushing the bike into the garage:
So I shoved the bolt back in and checked the other side: Luckily the Nut was still there. I've threaded it back on as tight as I can by hand and flagged it while I figure out what the deal is here. Is there a torque spec for this assembly? Should I use thread lock? I can't have my wife crashing because her swingarm dropped off the frame (or for any reason, really, but especially not as a result of poor maintenance on my part.) Mine: '74 CB750 K4 -- Hers: '64 CA78
Had: '75 CB550 K, '79 CT90 Bob - Make sure when you tighten that up, that the swingarm actuation doesn't get tighter too. That would mean that one or both of the bushings are worn a little too short, or there's a layer of paint on the swingarm bosses where it shouldn't be. In other words, when the swingarm rotates, it may tend to drag the nut loose. You should be able to tighten the nut and still have clearance between the washers and swingarm. Couldn't find a torque spec for that nut in either of the pdf shop manuals I have, but it's 40-50 ft-lb for other Hondas. That nut should also have a self-locking quality to it unless it's been on and off too many times. In that case, some blue loctite may be appropriate after you get all the grease off the threads.
-48 Later today, I'll make sure paint is not interfering. and clean up the threads. But that nut was a new purchase from Tim at CHR so it's not old. It doesn't seem very grabby in the self-locking sense. It turns easily all the way to the washer. I may try to get a lock washer in there and use the blue thread lock. We'll see. I do remember when I first reassembled it, that I could lift the swingarm, tighten it, and it would hang there by itself. So I backed off a little on the torque to allow better movement. I think that will have something to to with the clearance at the bushings as you mentioned. Hopefully it's just paint, since it didn't have this issue prior to disassembly.
When I disassembled I used all the methods I could at the time to remove those bushes and replace them, (vice with sockets, etc) but I could never get them to budge, so I left them in. If what I try today doesn't feel right, I'll find someone local who can press those out and press some new ones in (which I'll have to acquire first).
Last edited by Bob750 on Mon Feb 24, 2014 4:27 pm, edited 1 time in total.
Mine: '74 CB750 K4 -- Hers: '64 CA78
Had: '75 CB550 K, '79 CT90 I didn't realize that was counterfeit nut! Guess they went for aesthetics over safety... Anyway, those bushings are assemblies with an inner and outer tube with rubber in between. Nothing slides, the rubber just flexes to allow the swingarm to move, so it may feel stiffer than your 750 for instance. The nut and bolt should only tighten against the inner bush (which should be slightly proud of the outer, leaving the outer (which is a press fit in the swingarm) free to move with the swingarm. The bushing probably isn't worn, just has paint on the outer tube. Hope this all makes sense, if not give me a call.
Okay, so the swingarm situation was just me not having it tight enough. I torqued it to 45 lb-ft and it hasn't budged in over 100 miles. I'm getting a drop of oil on a few of the nuts on the bottom case. No heavy leaks, just a drop hanging off. These are not the ones around the oil pump or the special one next to that--these are other ones. So I'm thinking of tightening those a bit in case they've loosened. But they aren't finger-loose, soo...
The head gasket seep seems to have nearly stopped, I think it's still seeping a small amount into the cylinders though. So I'm going to get a thicker (OEM?) head gasket and plan for swapping that out some day. The fuel consumption seems a little high--45 mpg or so. Even though it was up around 100 before the tear-down. Does breaking in new rings on a fresh honing add that much friction? Though unlikely, I thought maybe my mixture might be off (bad float setting or needle too high (it's in the center slot)). But I doubt those are at issue. It doesn't smoke or smell too rich. I pulled the plugs (200 miles on new D8HAs). I think they look good; do you? There is no black smoking, just a rare few symmetrical blue-white puffs at cold start after a couple weeks of inactivity, which I attribute to the head gasket. I'll be checking the valve clearances to see if they've moved in the 200-odd miles it's been running since I did them before installing the motor. But it runs great. There really isn't anything wrong, but the gas mileage seems low... Any thoughts? The brakes are not dragging, btw. Mine: '74 CB750 K4 -- Hers: '64 CA78
Had: '75 CB550 K, '79 CT90 Bob - I'd be happy with 45 mpg, that's about all you'll get. These motors were designed way before anybody cared about gas mileage. Those plugs look great, especially for 8's. I usually run 6's in the Dreams but I wouldn't change what you have there. You've done a great job on that bike, and like I often remind myself - Don't be afraid to quit when you're finished... Plenty of CB77's out your way waiting for that kind of attention!
-48 Thanks for the reply, 48.
I've already decided not to go all hardcore and try to get high points on the Concours circuit. That's going to save time, money, and heartache. It also frees the bike up to get a solid state Reg-Rec and Halogen Headlight, which will allow all-day, high-beam riding without killing the battery, and later on, maybe even an Electronic Ignition. We also want to get some directional signals on it for safety. I just think that it should be getting better mileage; I'd hate to think that tuning it up increased the fuel consumption from the really great rate it was getting before I took it apart. We'll see... I'm just going to track it and see if it improves. I'd enjoy doing a CB77, but first I've got to tackle my CB750. (I'll post a link to my SOHC4 thread when that happens.) Then, we'll probably seek out a CB400F so my wife can have an easy-to-handle spirited bike that will do the freeway. She loves the Dream (and so do I now), but it's not a freeway bike, and that kind of limits where we can go for motorcycling adventures around here. Don't worry though; we won't sell the Dream until we're both too old to ride! Cheers!
Mine: '74 CB750 K4 -- Hers: '64 CA78
Had: '75 CB550 K, '79 CT90
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