Author Topic: '77 550 project  (Read 1768 times)

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Offline coldchris

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'77 550 project
« on: August 31, 2016, 12:29:47 PM »
Greetings all,
I've just received a "new to me" 1977 CB550 for a birthday gift from a friend who scored a HD Sportster. I also have a 1981 CB900F that has taught me a lot about attempting to be a garage motorcycle mechanic. I must say these SOHC Hondas are way easier to work on than the DOHC electric only start Hondas. So here is where I am at...

Issues
  • Carbs idle at 2000 after the synch
  • Oil leaking from between cylinder head and cylinder
  • Can't seem to get good flow from the gas tank

I've removed the cylinder head and torqued the nuts down in sequence and to the specs. I'm hoping to get everything put back together before the weekend so I can spray the motor down with the pressure washer and start her up to see if it's still leaking. Once I've got that issue resolved I'll tackle the rest.
« Last Edit: September 15, 2016, 11:35:58 AM by coldchris »
1977 CB550 (cafe to chopper project)
1981 CB900F (on hold until the 550 is finished)

Offline coldchris

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Re: First time with a SOHC, '77 550
« Reply #1 on: September 01, 2016, 06:58:54 AM »
Thanks for the advice calj737,
I put everything back together before I read your reply so I wasn't able to torque the head again after it sat overnight. That is a great piece of advise that I will use the next time I have to open her up.

As for the idle, it's at 2k with the idle speed screw all they way out. I did the bench synch with a 1/8" drill bit and it still was idling high. I'm going to attempt the carb synching again then take the bike around the block and make sure the oil leak is solved first. I ran it for a few minutes just to make sure that it would start again and so far, so good, no oil leakage.

I do have aftermarket inline fuel filters so I will empty the gas tank and remove the petcock to see the condition of it. I'm hoping it has a filter inside so that I can eliminate the inline filters. Regarding the tank vent, am i correct in assuming it's the hose coming from the bottom of the tank towards the front? I have no experience with this. Could I remove the hose and not run into any problems?

I doubt that I'll ever buy another DOHC bike after my pleasant experience with this SOHC.
1977 CB550 (cafe to chopper project)
1981 CB900F (on hold until the 550 is finished)

Offline coldchris

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Re: First time with a SOHC, '77 550
« Reply #2 on: September 04, 2016, 12:57:40 PM »
So I removed the after market inline fuel filters after I discovered the petcock already had a filter inside the tank. The issue is I still have an oil leak issue and smoke is coming from the 1 and 2 cylinder spark plug holes. Any help is appreciated guys.
1977 CB550 (cafe to chopper project)
1981 CB900F (on hold until the 550 is finished)

Offline Restoration Fan

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Re: First time with a SOHC, '77 550
« Reply #3 on: September 05, 2016, 04:10:15 AM »
Is it leaking between the head & the cylinders?  If so, you should replace the head gasket after thoroughly cleaning the mating surfaces.  While you're in there, replace those rubber pucks and follow the procedure cal outlined.
Ron

Stella - Logan's Senior Project    78 750K http://forums.sohc4.net/index.php?topic=141761.0

Logan's Reward - CB500 and CB550 Cafes    http://forums.sohc4.net/index.php/topic,147787.0.html

Offline coldchris

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Re: First time with a SOHC, '77 550
« Reply #4 on: September 06, 2016, 08:04:57 AM »
I've ordered the rubber pucks from 4into1 since mine were stiff and didn't want to stay on after the initial tear-down. I'll clean the mating surfaces, put on a new gasket and torque things down in two stages. I'm hoping to get this sorted out soon. Thanks for the help guys.
« Last Edit: September 06, 2016, 10:41:51 AM by coldchris »
1977 CB550 (cafe to chopper project)
1981 CB900F (on hold until the 550 is finished)

Offline coldchris

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'77 550 project / Need to replace cam chain, HELP!
« Reply #5 on: September 12, 2016, 03:09:14 PM »
Got the gaskets on without a hitch. Started right up and no oil leak. Then I hear a noise and the motor stops, my heart sunk down to my stomach. I forgot to tighten the first bolt that I put onto the cam sprocket. I only but it on finger tight and meant to torque it down once I installed the second bolt. Needless to say, I need to replace the cam chain and find the missing bolt, which should be in the oil pan.
« Last Edit: September 15, 2016, 11:29:10 AM by coldchris »
1977 CB550 (cafe to chopper project)
1981 CB900F (on hold until the 550 is finished)