Author Topic: CB750 K3F - AKA The Red (Read 119550 times)

70CB750 · « **Reply #50 on:** April 02, 2013, 06:08:47 AM »

Jugs off and broken ring. I will replace all rings.

70CB750 · « **Reply #51 on:** April 02, 2013, 06:10:29 AM »

Getting remnants of gasket off - just elbow grease, carb cleaner and scotch brite.

iron_worker · « **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.

IW

70CB750 · « **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

70CB750 · « **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.

70CB750 · « **Reply #55 on:** April 12, 2013, 05:00:29 AM »

New rings. The oil ring wave is sideways compare to the original.

70CB750 · « **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

70CB750 · « **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.

70CB750 · « **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.

iron_worker · « **Reply #59 on:** April 18, 2013, 07:11:15 AM »

Nice. Are you going to measure the piston/bore clearance or just giver?

IW

70CB750 · « **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.

iron_worker · « **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

70CB750 · « **Reply #62 on:** May 13, 2013, 05:25:15 AM »

Old ring, sharpened to help clean ring grooves.

70CB750 · « **Reply #63 on:** May 13, 2013, 05:26:21 AM »

Rings installed on #2.

70CB750 · « **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.

70CB750 · « **Reply #65 on:** May 13, 2013, 05:28:59 AM »

To oil rings and pistons, old tootbrush works like a charm.

70CB750 · « **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.

70CB750 · « **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.

70CB750 · « **Reply #68 on:** June 18, 2013, 05:39:53 PM »

Jugs installed, took some preparation and anxiety but they are safely on.

70CB750 · « **Reply #69 on:** September 02, 2013, 09:26:19 AM »

Change to K3 frame to utilize F steering lock.

70CB750 · « **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:

70CB750 · « **Reply #71 on:** September 05, 2013, 05:55:47 PM »

Painting pieces.

70CB750 · « **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.

70CB750 · « **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.

70CB750 · « **Reply #74 on:** September 05, 2013, 06:03:49 PM »

F swingarm completely stripped and primed.

News:

Author Topic: CB750 K3F - AKA The Red (Read 119550 times)