Topic: 78 CB 550K motor rebuild

[DaveBarbier]

Ah, I thought the dowel for the case halves were hollow but I was wrong. I was thinking of the 650.

[MRieck]

This question is particulalry geared towards Mike. By any chance did you included 3 different sets of the same dowel? I have one that came with spark plugs, I'm guessing that's for the head. The other set of the same size would be for the cases and I already have one for the block which is a different size? Also anyone know where this clip could go not seeing anything thats is half shapped like this one?

There are 2 solid dowels (10X16) for the head to cam cover. That clip looks like a carb needle clip. I can't recall one like that anywhere else in the engine BUT that doesn't mean it doesn't.

[AlekStooge]

The clip is from the kickstarter.

[AlekStooge]

I cleaned the all the parts with denatured alcohol, wiped them dry and put assembly lube after putting in oil seals. I think I'm done with the bottom case, just needed to put the dowel in and wipe the cases surface.

Take a look see if everything's good to go.

Tomorrow I'm cleaning the top case, installing rings, then Honda Bond and torqueing it all down.

[DaveBarbier]

You said, "just needed to put the dowel in..." The case uses two locating dowels. Not sure if you just missed an "s" .

And yeah, I use denatured alcohol as a final wipe down on bearing shells and case flanges but if you're actually cleaning oily parts acetone is better.

[AlekStooge]

One dowel in the top case, one in the bottom case. Ok, on the Acetone.

[DaveBarbier]

The dowels can go in either case (both top/both bottom). They don't have to be opposite each other. Looks good!

[AlekStooge]

Is this gear sliding over normal and/or will things fall into place once the shift forks are in?

Is there supposed to be assembly lube on the bearings I don't see any oil passages there?

[DaveBarbier]

Not an issue, those gears are held in the proper place by the shift forks. Make sure the forks are in alignment with regards to the gears when you drop the cases on. Don't want to force anything.

The outer race of the bearing doesn't spin so no need to have lube on it. I'd clean it off so it doesn't get on to the case flange and render the Hondabond useless.

[AlekStooge]

Oh yeah the shift fork shaft (part 5)has a thread on one side. I left that end facing towards the side of the case it goes in on.The other side of the case is solid. I not sure what threads in there?

http://www.cmsnl.com/honda-cb550k-1978-usa_model7222/partslist/E++16.html#results

[AlekStooge]

Is this amount of gap between the cases normal? The clutch and countershaft spin freely.

[SOHC4 Cafe Racer Fan]

Is this amount of gap between the cases normal?

No.

[DaveBarbier]

That shift fork part has nothing threaded into it on the clutch side. You have it in the correct position. I think all the threads are there for is ease of removal. Picture if that shaft was seized, it would be very hard to remove it. But since it's threaded you could put a bolt in and pull it out.

I suspect you're hung up on the tranny dowels. They have to be in pretty much the exact position for the dowel in the case to go into the hole in the tranny bearing. If you bolt it down as is, you risk punching a hole in the case.

[DaveBarbier]

A nice feature would have been a slot for a screw driver in the exposed part of that tranny bearing so one could rotate it to line it up. I should have worked for Honda!

[AlekStooge]

Someone please tell me the neutral rotor switch (#16) does not go on the inside of the cases?
http://www.cmsnl.com/honda-cb550k-1978-usa_model7222/partslist/E++10.html#results

Also where exactly do the pizza cutter wheels lay in the shift mechanism?






I should have taken pictures of this assembled.

It seemed like to me the larger on went where the cutaway is...but you can't rotate the shift drop enough to then later mount the arm that the wheel is attached to.

How about the smaller wheel?

[bwaller]

Little different but shows how the mechanism assembles.


Make sure you use #12 (collar)in this diagram on that one detent.


http://www.partsfish.com/oemparts/a/hon/506b8ba0f870023420a1e86b/shift-drum-shift-fork-shift-spindle


The lower bolt attaches with the primary shaft retainer.

[AlekStooge]

So I was right. The shift drum will not allow me to turn the plate around so the wheel is where the cutaway is and the arm can still be mounted.

Does the small wheel sit on top of the shift drum or in between the shift pins?

[DaveBarbier]

Here's a complete shot before I tore everything down.



You realize that the shift drum spins, right? It rotates as you shift. Assemble the parts like my and Brent's picture. Then with your right hand rotate the clutch shaft and use the shift lever to try each gear and neutral. You should be able to feel it go into each gear.

[AlekStooge]

I do realize it rotates. It just wouldn't rotate all the way around as I mentioned. It looks like the small wheel is at the cutaway.

[AlekStooge]

Alright I got it like yours Dave. However when I try to shift gears I don't feel anything move, the shift drum does not rotate. I don't really understand how the shift drum is supposed to spin if the small wheel has to sit in the cutaway?



I guess I just need a explanation of how the shift assembly works?

[DaveBarbier]

Then with your right hand rotate the clutch shaft and use the shift lever to try each gear and neutral. You should be able to feel it go into each gear.

Did you do this?  --^

I'll try and explain a bit by referring to your picture. The shift lever goes through the cases and is connected to the large arm on the left of the picture with the little spring. If you move the lever up with your foot the arm moves backwards rotating the shift drum CW one notch. That act brings the bike up one gear (2nd to 3rd for example). I think my mistake was telling you the shift drum "spins". It doesn't "spin" per se, it rotates in a ratcheting motion. Each ratchet is a different transmission position (neutral or a gear depending where you were to start).

The little pizza cutter wheel on the top right of the drum won't always be in that little pocket. Only when it's in that specific gear.

If you just start shifting gears you'll see what I mean. So do that. Shift gears. Now.

Also, watch the output shaft when you're in different gears. You'll see the gear reduction happening. Notice how fast you spin the clutch shaft vs how fast the output shaft is spinning. The higher the gear, the slower the output shaft spins in relation to the speed of the clutch shaft.

[b52bombardier1]

While attempting to change gears as Dave described above, it may help to spin the output shaft during the gear change. Some bikes need some movement of the output shaft to help the individual gears lash up with each other.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

[DaveBarbier]

While attempting to change gears as Dave described above, it may help to spin the output shaft during the gear change. Some bikes need some movement of the output shaft to help the individual gears lash up with each other.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

True. I said spin the clutch shaft, same function and it'll be more comfortable the watch the magic levers in the shifting assembly with left hand on the shifter and right on the clutch shaft.

[AlekStooge]

That is how I thought it works. I attached the gear shifter and twisted it to the left as if I was shifting up. I span the clutch shaft around, which it spins very easily but the drum won't rotate one bit, either with my hand or by the shift arm.

I tried making a video but it was too hard to spin the clutch shaft, shift gears and hold a camera. Could it be I'm not using enough force? I don't think so since you can shift gears pretty easily if you use your hand on the foot lever.

[DaveBarbier]

I'd say you aren't using enough force. The foot lever adds mechanical advantage because of the length. Holding a tiny nub and trying to rotate it isn't going to be easy. Try again