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Author Topic: Early cb750 head?  (Read 1485 times)

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Offline setdog

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Early cb750 head?
« on: February 16, 2018, 11:52:59 AM »
Is this a very early cb750 cylinder head?
« Last Edit: April 22, 2018, 02:58:36 PM by Glenn Stauffer »
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Offline MRieck

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Re: Early cb750 head?
« Reply #1 on: February 16, 2018, 12:22:02 PM »
Yes. To bad about the split spigot
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Offline setdog

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Re: Early cb750 head?
« Reply #2 on: February 16, 2018, 12:26:49 PM »
Quote from: MRieck on February 16, 2018, 12:22:02 PM
Yes. To bad about the split spigot

I know!! This engine has had alot of hands on it, and neglected to say the least, too bad.  I read somewhere those can be replaced, but I don't see/feel any kind of seem in the port.  Welding the crack seems a simpler solution

Does that make it complete junk? Couldnt the split just be filled in and smoothed out it's not major stress spot aside from carbs hanging off it.
« Last Edit: February 16, 2018, 01:03:54 PM by setdog »
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My toolbox consists mainly of hammers.

76 CB 200T. (sold)
75 CB 750 K5. (sold)
74 CB 750 K4. (current rider)
73 CB 750 K3. (build)

https://www.youtube.com/user/setdog100

Offline MRieck

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Re: Early cb750 head?
« Reply #3 on: February 16, 2018, 01:52:28 PM »
 Spigots can be replaced but it is tricky. They unscrew BUT you need heat and some luck. Also.....early spigots have a different thread than later heads. I know I have both spigots on hand....would have to find them.
 Later heads are better from an oiling perspective....those minuscule oil holes clog very easily.
« Last Edit: February 16, 2018, 01:55:26 PM by MRieck »
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Offline setdog

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Re: Early cb750 head?
« Reply #4 on: February 16, 2018, 01:59:11 PM »
I think a weld attempt makes sense as a first attempt to repair, if the weld doesn't work then maybe replace attempt
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My toolbox consists mainly of hammers.

76 CB 200T. (sold)
75 CB 750 K5. (sold)
74 CB 750 K4. (current rider)
73 CB 750 K3. (build)

https://www.youtube.com/user/setdog100

Offline Don R

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Re: Early cb750 head?
« Reply #5 on: February 17, 2018, 10:35:36 PM »
  I'm thinking they added the front center bolt around 23 or 26,000 serial number so it's before that. I have one that's confirmed two digit.
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Offline 754

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Re: Early cb750 head?
« Reply #6 on: February 17, 2018, 11:48:40 PM »
I would try  welding the spigot.
I have tried to take a few out, some come out, some strip.. so then you are welding anyway.
« Last Edit: February 18, 2018, 08:52:34 AM by 754 »
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Offline Terry in Australia

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Re: Early cb750 head?
« Reply #7 on: February 18, 2018, 01:17:02 AM »
Yep, that's a K0 head, get someone who's really good at TIG welding to repair it for you, it's not hard, you just need someone who's not gonna stuff it up. What's your engine number? Cheers, Terry. ;D
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Offline PeWe

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Re: Early cb750 head?
« Reply #8 on: February 18, 2018, 03:23:50 AM »
A head a Sandcast restorer will pay for?
Maybe you can get a fresh later head, refurbished and ported as trade-in?
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Offline Don R

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Re: Early cb750 head?
« Reply #9 on: February 18, 2018, 04:41:36 PM »
 That would be from a 69 to early 70 engine, the cylinder also is missing the extra center bolt. It would be fun to have the rest of the bike it came off of.
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Offline Terry in Australia

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Re: Early cb750 head?
« Reply #10 on: February 18, 2018, 09:33:35 PM »
Has anyone got a spare K0 cylinder block? I'm thinking about building a CB1500K0 V8............ ;D
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I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline Bill/BentON Racing

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Re: Early cb750 head?
« Reply #11 on: February 19, 2018, 07:35:17 AM »
Quote from: setdog on February 16, 2018, 11:52:59 AM
Is this a very early cb750 cylinder head?
Yes

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Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
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1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
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Offline Bill/BentON Racing

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Re: Early cb750 head?
« Reply #12 on: February 19, 2018, 07:36:01 AM »
Quote from: setdog on February 16, 2018, 11:52:59 AM
Is this a very early cb750 cylinder head?
Fins good? How much?

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BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE
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