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Author Topic: CB750 Head and bore (machine work) & 836 options  (Read 12007 times)

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Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #50 on: June 18, 2009, 07:54:19 PM »
Help me out here guys, it's my first rodeo...

I'm getting the head off to pack it up. What all should I remove before packing? Can I just take the CAM chain apart at the master link and pull the head? Is it possible to get the head off without removing the CAM and rocker arms? The bolts look like they'll be difficult to get out with the rocker arm assemblies there.

« Last Edit: June 18, 2009, 07:57:19 PM by michrobi »
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #51 on: June 18, 2009, 09:20:44 PM »

Never mind all that, I took it all off. So what's the trick to getting the head unseated from the cylinders without damaging the fins or the surface? 



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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline 754

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #52 on: June 18, 2009, 09:32:19 PM »
get the puckoutahere... ::)

 Take out 4 of the rubber pucks and (carefully ) remove the 4 screws hoding the cylinder to the head...

 We can tell, you are not reading the manual, mayber you know something we dont?
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline BLUE71TURBO

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #53 on: June 18, 2009, 09:39:23 PM »
Then you can gently tap the head with a rubber mallet, then use a couple of punches or large screwdrivers, one in a
intake port and one in a exhaust port at the other end and lift up.  ;D
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Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #54 on: June 18, 2009, 10:12:30 PM »

Ouch, you're right. I "yadda yadda''d my way over that diagram assuming those 4 were just left out on my year. Sorry about that, I never saw a puck before  :-X

Its off, Looks like I can ship it tomorrow. Thanks for the help guys, I couldn't do this without you and I appreciate it a great deal.   :)
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #55 on: June 21, 2009, 01:44:32 PM »

Regarding transmission options, Cxcle-x offers a nice exchange program that includes bead blast, magnaflux the gears and an undercut. All for a very reasonable price. Everyone I've talked to says they send their transmissions to Big Jay, but in the trans section of APE's site all that is mentioned is the undercut, and it's $50 more than the Cycle-x trans.

I have a laundry list of stuff I'm planning to send to Big Jay, including rods and the crank - so I just want to be clear about APE's trans service before I decide where to go. Has anyone got an opinion one way or the other?
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline 754

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #56 on: June 21, 2009, 06:31:20 PM »
If 50 bux diff from a good supplier is a dealbreaker... save your pennies.. and stay at 736cc, you will feel better..
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #57 on: June 21, 2009, 07:05:35 PM »
At least he isn't shipping to Canada  ;)

I'd be interesting in hearing a good comparison. Let's see what Jay has to say about their procedures.
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As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #58 on: June 22, 2009, 10:54:00 AM »

Well boys, looks like I'm getting the Cobra back.  :D
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline BLUE71TURBO

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #59 on: June 22, 2009, 11:00:22 AM »
CONGRATULATIONS !  I hope you and your father are on good terms now. Now you have two bikes to play with !
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Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #60 on: June 22, 2009, 11:04:07 AM »
Same bike, just 2 motors to play with  8)
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline BLUE71TURBO

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #61 on: June 22, 2009, 11:17:33 AM »
I sent ya a PM.
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Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #62 on: June 23, 2009, 08:19:42 PM »

I picked the Cobra up today, and here she is fresh off my truck...







Now for the bad news...



This shot wouldn't take in focus, but you get the message.



A few other goodies my dad had in his attic...

stock header in really good shape.



A couple 77/78 heads in really good shape



A perfect 77 case



And who knows what's all in here, but it's going to be fun going through it. (look at how pristine those cam tensioners are!)



I'll start a new thread for the tear down and possible resurrection so I don't derail my own 836 thread, but there she is.
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline 754

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #63 on: June 23, 2009, 09:02:03 PM »
Can I have it.. ???

 looks more like a 1080..

 I found the case number.

...............................................................................

 If that was a Vincent, Crocker, 2cam JD, 8 valve HD or Indian... a lot of people would be happy to get those cases..

 Seeing as this is a bit newer version, of the previously mentioned classics.. I would certainly not ignore the possibility of fixing them.. I know folks put a lot more work than that will take, into modifying a head , or a frame, or building wheel hubs..
« Last Edit: June 23, 2009, 09:26:12 PM by 754 »
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #64 on: June 23, 2009, 09:36:12 PM »
What would they cut up another sandcast to patch it with, or how would they go about it? You really think it could be fixed? A 6000 is pretty cool, I love the idea it could be fixed!

Can you have what, the Cobra?   ;D
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline 754

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #65 on: June 23, 2009, 09:55:37 PM »
Yeah, the cobra.. ;D

 If it was diecast I would cut parts out of other cases.. Or you can cast them

 First you need a good welder that does that type of work... in my life I have found that nearly all welders SAY they can do it.. :o

 I am thinking  a casting may weld better, although more work. However you might get away welding the diecast piece in and blasting it to match.

 Just be patient, put it aside, it is worth doing.. IMO.
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline 754

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #66 on: June 23, 2009, 10:07:01 PM »
If you are in SLC area, in Sept at Miller Motorsport there is a vintage bike race.. between that & BUB, you will have no trouble finding a good welder..
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline michrobi

  • Goldenrod blew a 5" hole out the front with a
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Re: CB750 Head and bore (machine work) & 836 options
« Reply #67 on: June 23, 2009, 10:13:49 PM »

What's BUB? I'll definitely start looking, and make sure to hit that event at Miller. Thanks for the info man.
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline michrobi

  • Goldenrod blew a 5" hole out the front with a
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Re: CB750 Head and bore (machine work) & 836 options
« Reply #68 on: June 23, 2009, 10:22:20 PM »

I have a closeup of the case # in that parts wanted thread, here it is again though.

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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?

Offline 754

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #69 on: June 23, 2009, 10:25:17 PM »
Bub Speed Trials.. Wendover Utah  Salt Flats

1st week of September, bikes only.. bring your dad..
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline BLUE71TURBO

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #70 on: June 23, 2009, 11:09:07 PM »
I was wondering where is the magneto your were talking about earlier?
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Offline michrobi

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Re: CB750 Head and bore (machine work) & 836 options
« Reply #71 on: June 24, 2009, 08:33:43 AM »

The magneto was on there when my dad put it in the F, but he changed it out for an electronic ignition right after that so he could commute. I forgot about that, but in my defense it's been 10 years and lots of beers since the Cobra let go. The electronic ignition that was on the Cobra had to be swapped over to the 76K that is in the bike now.



In short, no magneto. Sorry guys.
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-Mike

'78 CB750F All stock except for the powerplant. Jived it off my Dad in the spring of '94. He had it since 1980 and it's the first bike I ever rode on.

Current project: http://forums.sohc4.net/index.php?topic=67756

How's them SOHC4 patches coming?
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