Author Topic: CB750 K3F - AKA The Red (Read 103805 times)

70CB750 · « **Reply #100 on:** October 23, 2013, 03:12:58 am »

Looks like the shocks the K0 had when she got to me are better than I thought. They can be disassembled just by unscrewing and they clean well. One less thing to buy, I will just fill them up with new oil and call it.

Stev-o · « **Reply #101 on:** October 27, 2013, 08:58:52 pm »

Did you find the shock "condom"?

70CB750 · « **Reply #102 on:** October 28, 2013, 03:01:18 am »

Seems like it:

http://www.mcmaster.com/#rubber-caps/=p4p420

70CB750 · « **Reply #103 on:** October 28, 2013, 04:37:50 pm »

Filled them up, no leaks, they feel good by hand.

Stev-o · « **Reply #104 on:** October 28, 2013, 05:02:33 pm »

Is that the best oil to use.....ha!

70CB750 · « **Reply #105 on:** October 28, 2013, 05:22:38 pm »

It was easy pick - they had no other brand. At the price, it better be good

70CB750 · « **Reply #106 on:** November 06, 2013, 03:51:43 am »

Those rubber caps work like a charm. All I had to do was to punch a hole in it.

70CB750 · « **Reply #107 on:** November 14, 2013, 01:16:09 pm »

Got me new valves!

I had this secret hope that they will fit with just lapping - there is actually visible crack between the valve and the seat

No lapping could fix that, gotta invest in Neway cutters.

70CB750 · « **Reply #108 on:** November 19, 2013, 03:45:16 pm »

Verified that valve seats have to be recut. The lapping atempt shows how the polished ring stops, meaning the concentricity is off.

Stev-o · « **Reply #109 on:** November 20, 2013, 05:27:51 pm »

Well, no harm in hope, right?

70CB750 · « **Reply #110 on:** November 20, 2013, 06:52:32 pm »

Exactly, besides I like to measure or at least see what I am fixing.

70CB750 · « **Reply #111 on:** November 21, 2013, 08:59:18 am »

Buying goodies.

cheftuskey121 · « **Reply #112 on:** November 21, 2013, 09:13:16 am »

What is that?

70CB750 · « **Reply #113 on:** November 21, 2013, 09:14:33 am »

Valve seat cutter. More here:

Honda CB750 cafe SOHC4 Neway Valve Seat cutting.AVI

edwardmorris · « **Reply #114 on:** November 21, 2013, 10:09:39 pm »

Did you buy all three angles and cut them yourself?

70CB750 · « **Reply #115 on:** November 22, 2013, 12:22:02 am »

I just bought one - 30 and 45 - and will cut and see. There is a school of thoughts that 45 is enough for anything but racing applications.

If I don't like the sealing surface I will invest in the last one, it would mean another delay, thats all.

iron_worker · « **Reply #116 on:** November 22, 2013, 10:01:53 am »

Correct me if I'm wrong but the 30 degree is the actually seat face while the 45 and 60(?) are for the valve throat/transition area? Cutting the 45 and 60 degree angles are more for better flow to the valve than actual seating of the valve?

IW

70CB750 · « **Reply #117 on:** November 22, 2013, 10:09:56 am »

Hmm, I think the sealing surface is 45 degrees with 30 and 60 degree narrowing/positioning cut.

edwardmorris · « **Reply #118 on:** December 07, 2013, 10:07:16 pm »

Hey, nice work on the swingarm, but how did you get the old bushings out? I'm debating if I should replace mine since I'm upgrading all the bearings and such...

70CB750 · « **Reply #119 on:** December 08, 2013, 04:30:36 am »

It was one of those plastic bushings in the F arm, it came out by itself. I think after baking the arm in the oven to harden the paint, the bushings were really loose.

But I hammered bushings out of the K0 swingarm with a long piece of 1/2" rod. It had a collar near the low end - the rod I mean - and that gave me purchase on the bushing and it took only a minute of hammering around to get it out.

I believe the 750 bushings are the easiest.

edwardmorris · « **Reply #120 on:** December 08, 2013, 03:44:22 pm »

Quote from: 70CB750 on December 08, 2013, 04:30:36 am

It was one of those plastic bushings in the F arm, it came out by itself. I think after baking the arm in the oven to harden the paint, the bushings were really loose.

But I hammered bushings out of the K0 swingarm with a long piece of 1/2" rod. It had a collar near the low end - the rod I mean - and that gave me purchase on the bushing and it took only a minute of hammering around to get it out.

I believe the 750 bushings are the easiest.

What kinda collar? Just a cut washer or anything special? I suppose a pic would probably explain it all if you have one

70CB750 · « **Reply #121 on:** December 09, 2013, 02:48:02 am »

Actually Terry asked about it too:

http://forums.sohc4.net/index.php?topic=88103.200

The collar is welded on it, it's original purpose was to drive duck beak anchors in the ground

edwardmorris · « **Reply #122 on:** December 09, 2013, 10:10:50 am »

Thanks that helps! I'll have to rig something up now...

edwardmorris · « **Reply #123 on:** December 09, 2013, 03:10:52 pm »

Also, (if you don't mind me hijacking this thread) the bronze ones (number 1 choice from all the searching I've done) you used are different than the stock ones, with the extra collar on them. Is this to eliminate the use of the felt washer and/or more? I'm asking because I was wondering if you had any fitment issues after installing these with the collars taking up more space. I am guessing the collars help keep the water out?

70CB750 · « **Reply #124 on:** December 10, 2013, 05:17:18 am »

Hmm, I did not install the swing arm yet, just did some quick measuring and it looks like it will fit right in.

The flange on the bushing should help with the swing, basically all moving parts in the "hinge" will be on bronze surface.

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Author Topic: CB750 K3F - AKA The Red (Read 103805 times)