Author Topic: 78 CB550 full rebuild  (Read 6029 times)

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Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #25 on: July 26, 2015, 05:36:18 AM »
Yes, I am using the ones that look like a nozzle.

Offline P.abrera

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Re: 78 CB550 full rebuild
« Reply #26 on: July 26, 2015, 05:56:30 AM »
You sure the dowel pins are the right way up?


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Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #27 on: July 26, 2015, 06:56:53 AM »
I just verified that they are in right, the larger end with the cone shaped end is down and the flat end is up.


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Offline Desert Dan

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Re: 78 CB550 full rebuild
« Reply #28 on: July 26, 2015, 11:16:20 AM »
On the 500 and 550 the cam chain tensioner is a real PITA and when installed correctly will keep the cylinders from sitting flush until you bolt down the head.

Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #29 on: July 26, 2015, 11:23:48 AM »
Thank you Desert Dan, I was hoping that would be the case.

Thank you everyone for the input!


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Offline Desert Dan

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Re: 78 CB550 full rebuild
« Reply #30 on: July 26, 2015, 12:21:04 PM »
Thank you Desert Dan, I was hoping that would be the case.

Thank you everyone for the input!


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Glad I could help out, just be sure the bottom of the cam chain tensioner assembly is correctly located in it's nook in the case before you go bolting the head on. Good luck with the rest of your build.

Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #31 on: October 24, 2015, 11:57:12 AM »
Hey guys,
Well I am finally back at it and I think I have run into a massive issue. The 3 bolts indicated in the picture will not tighten down and I am not sure what could be going on. Any ideas would be appreciated.

Offline flatlander

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Re: 78 CB550 full rebuild
« Reply #32 on: October 24, 2015, 01:06:34 PM »
what do you mean exactly? they don't go all the way down in the threads, or they're in but keep turning (stripped threads)?

Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #33 on: October 24, 2015, 01:12:39 PM »
They are in but keep turning so I guess that would be stripped threads. Is there a way to fix that?


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Offline flatlander

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Re: 78 CB550 full rebuild
« Reply #34 on: October 24, 2015, 01:51:30 PM »
yes, look for an M6 thread repair set. most common brand is helicoil. they come with a drill bit, thread insert, and a tool to get the insert into the new hole. basically you drill out the stripped thread and replace it with a coil that forms the new one.
no need to despair - you can fix that :)

Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #35 on: December 09, 2015, 03:20:11 PM »
Hey guys, I am back at it and have a strange electrical issue. It has to do with the turn signals and tail light. If I turn on the right turn signal both right lights and the tail light flash. If I turn on the left turn signal the left rear and tail light flash and the front right turn signal flashes dimly. Unplugging the brown wire from the tail light prevents it from flashing. Any ideas?


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Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #36 on: December 09, 2015, 05:39:15 PM »
I figured it out, it was a dirty switch. Now my issue is that I don't have running lights on the front (as I recall the turn signals would act as running lights), the speedo and tach lights dont work and the tail light only works when I push the brake lever. It seems that all of these have one thing in common and that is that they should come on with the ignition switch, so could the problem be the switch? Is there a way to test that?

Offline calj737

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Re: 78 CB550 full rebuild
« Reply #37 on: December 09, 2015, 05:43:14 PM »
BR/WHT wire from the left side panel. Check the fuse  ;)
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #38 on: December 09, 2015, 05:52:09 PM »
Fuses are all new. Starting left to right this is what I get on the meter tail=0 head=0 main=12.65 blank=13.5 blank=0


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Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #39 on: December 09, 2015, 05:53:57 PM »
The headlight was unplugged so with it plugged in head=.15


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Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #40 on: December 09, 2015, 06:08:27 PM »
Does this look right?


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Offline calj737

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Re: 78 CB550 full rebuild
« Reply #41 on: December 09, 2015, 06:58:25 PM »
retest the voltage on each side of the fuses with the key ON. Then test the backside of the fuse block too.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #42 on: January 03, 2016, 12:05:29 PM »
Ok everyone, I need some help. I got it back together finally and tried to start it today. Attached is a video of the attempt. Does anyone have any ideas from the sound it's making? I know it's a long shot but I figured everyone has helped a lot here already.


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Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #43 on: January 03, 2016, 12:32:29 PM »
Another find


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Offline calj737

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Re: 78 CB550 full rebuild
« Reply #44 on: January 03, 2016, 03:07:58 PM »
Sounds like your cam is installed with the timing wrong. Either that or your coils are wired backwards. Confirm the #1 piston is at TDC, then check your valve clearances. If these are correct, then I'd swap your coil leads from the igntion plate and see if that doesn't make it fire promptly.

Grinding away with the electric start will wear your battery quickly. Might want to throw a charger on it.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Tews19

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Re: 78 CB550 full rebuild
« Reply #45 on: January 03, 2016, 03:09:21 PM »
Cam off a tooth??? Wow that sounds really weird and bad.
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Offline Trad

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Re: 78 CB550 full rebuild
« Reply #46 on: January 03, 2016, 09:29:21 PM »
I agree. Somethings out of time or order, man.
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Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #47 on: January 04, 2016, 03:51:17 PM »
Is there a way to check the cam chain placement without pulling the cam cover?


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Offline calj737

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Re: 78 CB550 full rebuild
« Reply #48 on: January 04, 2016, 04:11:20 PM »
Confirm the easy stuff first. Swap the coils/plugs around. It could be you're timed correctly but the ignition is firing in reverse.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline sboubel

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Re: 78 CB550 full rebuild
« Reply #49 on: January 04, 2016, 04:15:04 PM »
I did that and had the same thing happen. I'm gunna check the valve clearances next.


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