Author Topic: '74 CB550 Head Gasket  (Read 358 times)

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Offline 88BuckMeister

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'74 CB550 Head Gasket
« on: January 16, 2024, 08:43:47 AM »
Hey all. I'm the new guy. Glad to be here, since I've utilized this forum religiously for 2 weeks now! I'm assembling a CB550 top end right now. It has the 591cc 61mm Dynoman big bore kit in it. I wasn't sure about putting anything on the base gasket, so I just lightly lubed it with assembly lube (I'm an A&P aircraft mechanic so I have the good stuff at work), mimicking the paste pattern you see on OEM NOS base gaskets in pictures. I have an '82 CB650SC camshaft on the way to finish the mod (the guy I bought the bike from sent his cam into Web, and had them take a racing cam and do a custom grind to FACTORY SPECS which I found extremely bizarre) so I have a factory spec brand new Web cam but I'm going the 650 cam route unless any of you scream at me not to.

So to my question...the OEM honda head gaskets do appear to have some sort of assembly paste on them. Should I torque this head gasket dry? The surfaces appear to be pretty mint, no dings dents or damage...Im a federally licensed mechanic, but I'm fresh to the bike stuff and getting hooked fast with my 550, and open to any and all advise on this build. Thanks- Buck

Offline newday777

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Re: '74 CB550 Head Gasket
« Reply #1 on: January 16, 2024, 09:36:26 AM »
Welcome aboard the forum and the 550FOUR Buck from NH
What year is your 550?
The Honda head gaskets are usually put on dry, I think they have a graphite coating.

Go to the New Members section and introduce yourself and your bike there.

You can also start a project thread on the build in the Project shop section. We like pictures 📸 
Have fun with your project. It should be a fun ride with that motor build.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline exponent

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Re: '74 CB550 Head Gasket
« Reply #2 on: January 16, 2024, 10:10:09 AM »
In my experience torqueing down the head with a dry gasket is fine. That's how I went on mine and haven't leaked
'78 550K 2106630

Offline 88BuckMeister

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Re: '74 CB550 Head Gasket
« Reply #3 on: January 16, 2024, 10:34:42 AM »
Welcome aboard the forum and the 550FOUR Buck from NH
What year is your 550?
The Honda head gaskets are usually put on dry, I think they have a graphite coating.

Go to the New Members section and introduce yourself and your bike there.

You can also start a project thread on the build in the Project shop section. We like pictures 📸 
Have fun with your project. It should be a fun ride with that motor build.

Will do! And it's a 74. It's got the 591cc 61mm Dynoman Piston/rings kit in it. I'm opting to go the extra mile and ordered a 650 cam for it. Bike is otherwise in excellent, original condition.

Offline newday777

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  • Avatar is my 76 K6 in Colorado w/Cody on back 1980
Re: '74 CB550 Head Gasket
« Reply #4 on: January 16, 2024, 02:58:15 PM »
Welcome aboard the forum and the 550FOUR Buck from NH
What year is your 550?
The Honda head gaskets are usually put on dry, I think they have a graphite coating.

Go to the New Members section and introduce yourself and your bike there.

You can also start a project thread on the build in the Project shop section. We like pictures 📸 
Have fun with your project. It should be a fun ride with that motor build.

Will do! And it's a 74. It's got the 591cc 61mm Dynoman Piston/rings kit in it. I'm opting to go the extra mile and ordered a 650 cam for it. Bike is otherwise in excellent, original condition.
You said you got a OEM headgasket,  for the big bore kit you will need to obtain a bigger headgasket for the kit.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A