Author Topic: CB750 K3F - AKA The Red  (Read 63968 times)

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Offline 70CB750

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Re: CB750 K3F
« Reply #25 on: February 04, 2013, 03:20:08 am »
Removed the original top shock mount.  The hole is 12mm, the stud part for the shock is 15mm and the thread is M10.

Offline 70CB750

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Re: CB750 K3F
« Reply #26 on: February 05, 2013, 02:53:30 am »
The new shock mount to accomodate the wider F swing arm.  I used 3/4" 8 Grade bolt to make it, it still needs a washer beefore I weld it in.

Offline 70CB750

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Re: CB750 K3F
« Reply #27 on: February 05, 2013, 02:54:10 am »
The rear master cylinder mount is ready to be welded in.

Offline 70CB750

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Re: CB750 K3F
« Reply #28 on: February 05, 2013, 02:43:56 pm »


The shock mount ready to be welded in.

Offline 70CB750

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Re: CB750 K3F
« Reply #29 on: February 07, 2013, 03:14:01 am »
The top shock mount is welded in.  With some washers and spacers I will be able to line up the shock just right.

Offline 70CB750

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Re: CB750 K3F
« Reply #30 on: February 07, 2013, 03:17:41 am »
Here is the master cylinder mounted.  Now for the linkage.

Offline 70CB750

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Re: CB750 K3F
« Reply #31 on: February 08, 2013, 03:02:52 am »
Cylinder linkage and brake line mockup.

Offline 70CB750

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Re: CB750 K3F
« Reply #32 on: February 22, 2013, 04:24:07 am »
I emptied my work bench - had to fix chainsaw and replace forge blower motor first - and pulled the F engine head.

The #1 valve guides seem to be tight, but I have to check all of them.  Time to make C Clamp adaptor for spring compressing.
« Last Edit: February 22, 2013, 04:26:32 am by 70CB750 »

Offline 70CB750

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Re: CB750 K3F
« Reply #33 on: February 22, 2013, 04:25:42 am »
There is some carbon deposit, but nothing serious.

Offline SOHC4 Cafe Racer Fan

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Re: CB750 K3F
« Reply #34 on: February 23, 2013, 08:32:30 am »
That some cool adaptation work to mount the F MC onto the K frame with a made from scratch linkage.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2014 MV Agusta Brutale Dragster 800
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold

Offline 70CB750

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Re: CB750 K3F
« Reply #35 on: February 23, 2013, 08:52:10 am »
Thank you  ;D

Still trying to figure out the brake pedal setup.

Offline 70CB750

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Re: CB750 K3F
« Reply #36 on: February 25, 2013, 03:50:19 am »
Made an adapter for a C-clamp to be used as valve spring compressor.  It works well enough.

Offline 70CB750

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Re: CB750 K3F
« Reply #37 on: February 25, 2013, 03:54:23 am »
With valve springs off, I will need to measure and check the play between valve guide and the valve stem.  The leak test was positive - i.e. no leaks.  I used 2 stroke gas mix.  The passages under the exhaust valve and under the intake valve stayed dry, no gasoline made it past the valve. That is a good thing.

But # 2 and # 4 intake valves are in bad shape.  Look at the detail of #2, the hole is 0.8 mm deep.

Offline 70CB750

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Re: CB750 K3F
« Reply #38 on: March 01, 2013, 03:43:37 am »
Diassembled the valve train and cleaned top of pistons.

Offline 70CB750

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Re: CB750 K3F
« Reply #39 on: March 03, 2013, 04:58:03 pm »
Washing head in the kitchen sink  ;D
« Last Edit: March 04, 2013, 05:47:41 am by 70CB750 »

Offline iron_worker

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Re: CB750 K3F
« Reply #40 on: March 04, 2013, 06:36:07 am »
Who needs a parts washer?

lol

IW

Offline 70CB750

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Re: CB750 K3F
« Reply #41 on: March 11, 2013, 09:08:12 am »
The blasted head.

Offline 70CB750

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Re: CB750 K3F
« Reply #42 on: March 11, 2013, 04:26:59 pm »
I baked the head @ 300F, right after pizza,  and drove guides out with a drifter. 

The guides are actually visibly oblong.

Offline 70CB750

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Re: CB750 K3F
« Reply #43 on: March 13, 2013, 03:44:04 am »
I was not happy with the master cylinder location and alternating K brake pedal was just too half a$$ for my liking.

I moved the cylinder down and changed the angle too.

Offline 70CB750

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Re: CB750 K3F
« Reply #44 on: March 13, 2013, 03:45:20 am »
From  Grade 5 bolt turned a new pivot.

Offline 70CB750

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Re: CB750 K3F
« Reply #45 on: March 13, 2013, 03:46:02 am »
The pivot will sit in the frame like this.

Offline 70CB750

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Re: CB750 K3F
« Reply #46 on: March 13, 2013, 03:48:12 am »
The new brake pedal mockup.

Offline 70CB750

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Re: CB750 K3F
« Reply #47 on: March 21, 2013, 04:05:29 am »
I made a simple power source for electrical testing.

Offline 70CB750

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Re: CB750 K3F
« Reply #48 on: March 21, 2013, 04:07:46 am »
The neutral switch wire was loose, I pulled the switch out.  It just slides in and the little bolt and bracket holds it in.
« Last Edit: March 21, 2013, 04:10:44 am by 70CB750 »

Offline 70CB750

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Re: CB750 K3F
« Reply #49 on: March 21, 2013, 04:09:51 am »
This is were it came from, will replace the o ring and solder the wire back together.