Author Topic: CB750 K3F - AKA The Red  (Read 63960 times)

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Offline 70CB750

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Re: CB750 K3F
« Reply #50 on: April 02, 2013, 06:08:47 am »
Jugs off and broken ring.  I will replace all rings.

Offline 70CB750

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Re: CB750 K3F
« Reply #51 on: April 02, 2013, 06:10:29 am »
Getting remnants of gasket off - just elbow grease, carb cleaner and scotch brite.

Offline iron_worker

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Re: CB750 K3F
« Reply #52 on: April 02, 2013, 07:40:45 am »
Did you break your ring as you were taking it apart or did you find it like that? On mine, I'm pretty sure my ring was broken already and just along for the ride when I took it apart.  :o

IW

Offline 70CB750

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Re: CB750 K3F
« Reply #53 on: April 02, 2013, 08:06:43 am »
There are no scratches on the cylinder and the brake seems to be fresh cut.  Can't imagine how would it brake by pulling jugs up, but there are many mysteries out there.

Also it was in two pieces and I broke one piece in half just to get a feeling how much force it takes to brake it - I am sure you understand  ;D

Offline 70CB750

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Re: CB750 K3F
« Reply #54 on: April 11, 2013, 09:48:55 am »
Used M12x1.25 tap to clean up spark plug threads.  It was so hard going that I got scared and verified with an old plug that the thread is indeed M12x1.25.

Waiting for rings to move forward.

Offline 70CB750

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Re: CB750 K3F
« Reply #55 on: April 12, 2013, 05:00:29 am »
New rings.  The oil ring wave is sideways compare to the original.

Offline 70CB750

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Re: CB750 K3F
« Reply #56 on: April 12, 2013, 07:05:38 pm »
Spent a quality hour with bottle of Shiraz, ignition lock and key blanks making them to work.  Ended up with three keys - there is no motorcycle yet, but I got them keys  :D

Offline 70CB750

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Re: CB750 K3F
« Reply #57 on: April 16, 2013, 04:21:57 am »
Cleaned head and jugs with power washer and baked them in the oven afterwards to make sure they are dry. 

Offline 70CB750

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Re: CB750 K3F
« Reply #58 on: April 18, 2013, 03:22:37 am »
I honed cylinders with flex hone (320 grit, Brush Research) 30 weight oil and battery drill.

They are beautiful now.

Offline iron_worker

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Re: CB750 K3F
« Reply #59 on: April 18, 2013, 07:11:15 am »
Nice. Are you going to measure the piston/bore clearance or just giver?

IW

Offline 70CB750

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Re: CB750 K3F
« Reply #60 on: April 18, 2013, 07:54:00 am »
I would feel better if I could but I dont have the means to measure with enough precision.

But it is a low mileage motor since the guides were OK and valves just started to give up, it had a good compression and the only reason to rering was the broken ring on #2.

I will check it with digital caliper just for kicks, but that's not the way it should be done.

Offline iron_worker

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Re: CB750 K3F
« Reply #61 on: April 18, 2013, 08:25:57 am »
I believe you can use a feeler gauge to measure as well. It's not a perfect method but I think it would be more accurate than a caliper measuring IDs.

Slide the piston in the bore... might help to have the cylinders on their side and the try to stick a feeler gauge between the piston and skirt. The feeler gauges of this thickness range should be quite flexible so the curvature should be no problem. I think past .003" clearance is where Hondaman says they really start to drink oil and really should be bored.

IW

Offline 70CB750

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Re: CB750 K3F
« Reply #62 on: May 13, 2013, 05:25:15 am »
Old ring, sharpened to help clean ring grooves.

Offline 70CB750

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Re: CB750 K3F
« Reply #63 on: May 13, 2013, 05:26:21 am »
Rings installed on #2.

Offline 70CB750

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Re: CB750 K3F
« Reply #64 on: May 13, 2013, 05:27:36 am »
and compressed.  It was just a mockup with one piston to get the feel for the installation.  I was able to get jugs on using this simple compressor.

Offline 70CB750

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Re: CB750 K3F
« Reply #65 on: May 13, 2013, 05:28:59 am »
To oil rings and pistons, old tootbrush works like a charm.

Offline 70CB750

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Re: CB750 K3F
« Reply #66 on: May 13, 2013, 05:30:38 am »
In Manassas hardware store I found O-Rings for studs.  They are the perfect size for my needs.

Offline 70CB750

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Re: CB750 K3F
« Reply #67 on: May 20, 2013, 03:19:36 pm »
Jugs nicely masked as 255.255.255.0 - i am losing it. Masked jugs, ready to be painted.

Offline 70CB750

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Re: CB750 K3F
« Reply #68 on: June 18, 2013, 05:39:53 pm »
Jugs installed, took some preparation and anxiety but they are safely on.

Offline 70CB750

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Re: CB750 K3F
« Reply #69 on: September 02, 2013, 09:26:19 am »
Change to K3 frame to utilize F steering lock.

Offline 70CB750

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Re: CB750 K3F
« Reply #70 on: September 05, 2013, 10:03:37 am »
Seems like I always search for it, here is a reference on F3 head and valve train:



Offline 70CB750

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Re: CB750 K3F
« Reply #71 on: September 05, 2013, 05:55:47 pm »

Painting pieces.

Offline 70CB750

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Re: CB750 K3F
« Reply #72 on: September 05, 2013, 05:58:06 pm »


Old style bolt with new zerks and collar drilled for better flow of grease. Still needs groves cut.

Offline 70CB750

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Re: CB750 K3F
« Reply #73 on: September 05, 2013, 05:59:51 pm »


Took apart - with impact driver -  new to me seat  lock, it will need new cylinder.

Offline 70CB750

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Re: CB750 K3F
« Reply #74 on: September 05, 2013, 06:03:49 pm »


F swingarm completely stripped and primed.