Author Topic: 1972 CB750 Four K2 -- Rebuilt to NEW OLD STOCK -- PIX ON PAGE 50  (Read 242970 times)

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Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #450 on: April 01, 2014, 08:07:07 PM »
Thanks for the PM with detailed explanation Godffrey.

Made some time today to finish up on the MC. I couldn't find a small enough hone, so I just rolled up a third sheet of 2000 grit sanding paper and reamed it a bit. Worked well, and that thing that looked like a scratch is pretty much gone, was just brake fluid crud. I didn't push it too hard, this is how it looks right now. I will clean it out with denatured alcohol when it returns from Powderman then put it back together.

Offline seanbarney41

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #451 on: April 01, 2014, 08:12:34 PM »
Ed, that is not the correct MC for a K1, it should work fine though.  I believe the grooved sides of the reservoir indicate it is from a much later sohc.
If it works good, it looks good...

Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #452 on: April 01, 2014, 08:16:21 PM »
Ed, that is not the correct MC for a K1, it should work fine though.  I believe the grooved sides of the reservoir indicate it is from a much later sohc.
Mine's a K2, but you're probably right, the gauges, controls etc. were all from a later bike, and I replaced all that with the correct ones. At this point, I'm losing the will to care and just wanna ride ;) I'm sure once Marc does his magic, it will be hard to tell  ;D

Offline seanbarney41

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #453 on: April 01, 2014, 08:27:40 PM »
that's how I feel too generally...hang in there though
If it works good, it looks good...

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #454 on: April 01, 2014, 10:27:15 PM »
I think Sean's nailed that feature: it looks like the K6/F0/F1 (or so) version. Those appeared, along with another similar one, up to the K7/F2. The last of them had a little brake switch (mechanical) up on the lever instead of the pressure switch on the steering neck.
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Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #455 on: April 02, 2014, 12:44:51 PM »
Grrr! I can't help it  >:( I really tried to not care.

It has to be correct, so, on to other things that need done for now, as I wait for the correct MC to arrive.

Offline Tews19

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #456 on: April 02, 2014, 12:48:36 PM »
Hey shoot me a PM if you want a MC proper for the K2.... Pay shipping and it's yours. It will need to rebuilt. I can ship tomorrow as I am back in the bike scene
1969 Honda CB750... Basket case
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Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #457 on: April 02, 2014, 10:44:40 PM »
Hey shoot me a PM if you want a MC proper for the K2.... Pay shipping and it's yours. It will need to rebuilt. I can ship tomorrow as I am back in the bike scene
Sweet! Glad to have you back Nick, thanks for helping out!

Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #458 on: April 04, 2014, 02:12:59 PM »
After meticulously cleaning out the battery box, I realize it not the correct one  >:( which means the harness is incorrect as well as the K2 didn't have a starter safety unit or a 3 fuse holder. This bike is horse$hit I tell ya, complete and utter horse$hit. Time to slow down and see what else is wrong before working on it further...




Offline timbo750

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #459 on: April 04, 2014, 03:05:10 PM »
Hang in there. The result in the end will be so much more rewarding.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864


Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #460 on: April 05, 2014, 08:38:45 PM »
The K2 correct MC from Nick got here today, THANKS NICK!

Second time around this went quicker, torn, cleaned, boxed up and ready to go. Also, this one has a circular washer instead of the C-shaped one, so the bore is in much better shape.

Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #461 on: April 06, 2014, 12:18:30 PM »
I'm about half way through tearing down the oil pump for a full rebuild, and the shaft seal with the metal outer band is being a nightmare. Any tips on getting this out safely? So far the pump looks fairly scratchless on the insides but it might be a different story once I clean it thoroughly. I'm a little hesitant about going nuts with awls and pins in there.

There is a little bit of crap stuck behind the screen. I read around here that the screen can be bought from a boats place as its the same part used by Honda for their boats? Is this true? I would like to get the junk out from under it but if there is no guarantee for a drop in replacement, I'll leave it alone.

Also, do gasket kits (Vesrah from Jp specifically) include the gasket that is used in the oil pump body?

I've left the pump as is for now, will go read up some more and wait for suggestions. I believe once the oil pump is done, I can officially change the build thread title to inspection as the tear down will be complete.

Offline jerry h

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #462 on: April 06, 2014, 02:16:50 PM »
I bent the end of a small screwdriver, then was able to easily just tap it out from the outside. 






The gaskets do not come in any gasket kit.... here are the numbers needed :

2) 91305-426-003
1) 91208-MN1-771
4) 91302-377-000





There are other ways, this worked really well for me.  Put the new center seal in the freezer for a little bit before tapping in and it will go in very easily.

Hope this helps.
"It is not the critic who counts, the credit belongs to the man who is actually in the arena, whose hands are covered with grease and oil."

K2 http://forums.sohc4.net/index.php/topic,105097.0.html

Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #463 on: April 06, 2014, 03:20:15 PM »
Thanks Jerry, I have all the o-rings, the shaft seal and the infamous rubber stopper and spring. I got it all in Elan's super kit, and the only thing it didn't have was the screen.I was asking about the flat rectangular gasket that goes between the largest two parts of the pump. Don't have that either.

I'm having trouble getting the old shaft seal out. I tried to gently pry it out but its so old and horrid its starting to tear into bits. The metal ring that's on the outer of the seal is probably what is fused with the pump. Not sure how to get them to separate safely.
« Last Edit: April 06, 2014, 03:25:20 PM by edwardmorris »

Offline timbo750

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #464 on: April 06, 2014, 08:03:18 PM »
I would like to know more about the strainer and the associated boat part as I have not heard this before. Mine too had crud stuck in it and it is now slightly damaged after removing.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864


Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #465 on: April 07, 2014, 10:48:27 AM »
I would like to know more about the strainer and the associated boat part as I have not heard this before. Mine too had crud stuck in it and it is now slightly damaged after removing.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864
This is where I read it, I suppose we need to page Hondaman on this one as I've had no luck finding it on any boat parts site. Maybe the part number changed?

http://forums.sohc4.net/index.php?topic=101408.msg1241884#msg1241884

Offline Tews19

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #466 on: April 07, 2014, 01:13:50 PM »
I may have your battery box. If interested PM me buddy.
1969 Honda CB750... Basket case
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Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #467 on: April 07, 2014, 01:24:31 PM »
I may have your battery box. If interested PM me buddy.
Thanks Nick, I already found a cheap one.

Offline timbo750

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #468 on: April 07, 2014, 10:29:34 PM »
I would like to know more about the strainer and the associated boat part as I have not heard this before. Mine too had crud stuck in it and it is now slightly damaged after removing.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864
This is where I read it, I suppose we need to page Hondaman on this one as I've had no luck finding it on any boat parts site. Maybe the part number changed?

http://forums.sohc4.net/index.php?topic=101408.msg1241884#msg1241884
I just ordered a new screen from Yamiya assuming they actually have it in stock. But usually when its not in stock they won't let you order it.

Project 1 CB750 - http://forums.sohc4.net/index.php?topic=126864


Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #469 on: April 08, 2014, 10:33:19 PM »
Cool. I tracked one down at a dealership in WI, but they won't ship via regular mail. I'm trying to find someone who can pick it up and mail it to me.

After two hours of frustration, I stopped trying before I destroyed the oil pump. I tried Jerry's method but the seal is so crappy it disintegrated completely after only a few taps and all that is left now is the metal outer ring, fully infused into the case. There's one approach, which is to drill behind the seal using carb bits, but I'd rather not do that unless it becomes necessary. Would a machine shop be able to mill/grind/cut it out of the cavity? My local machinist has been great with helping out on my project (yes, the same guy who screamed death when I said the words "motorcycle parts") and may not charge me my left kidney.

Offline Kickstart

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #470 on: April 12, 2014, 02:49:14 PM »
Are you talking about the shaft seal in the oil pump (the one that you have to order as a Gl1000 part)?  If so, I was able to get mine out by very carefully using a small blind bearing puller from my cheap HF blind bearing puller kit.  I tightened up the puller just enough to not slip out when hammering.  It took a lot of careful attempts.

Machine shop would probably be your safest bet though.
- Chris
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Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #471 on: April 12, 2014, 03:53:53 PM »
Are you talking about the shaft seal in the oil pump (the one that you have to order as a Gl1000 part)?  If so, I was able to get mine out by very carefully using a small blind bearing puller from my cheap HF blind bearing puller kit.  I tightened up the puller just enough to not slip out when hammering.  It took a lot of careful attempts.

Machine shop would probably be your safest bet though.
Yup, that's the one. Eventually worked out though.

The shop out in Lowell IN, Midwest Accurate Grinding has the Blanchard Grinding Machine that Bill Benton pointed to earlier during the brake rotor discussion. I took the rotor there and fired in the dark, by asking if they had a way to get the seal out. They took a look and said they have a small milling machine that they don't advertise and offered to take care of it. Will be picking up both next  Friday (only time I have free), will post pix when  I have them here.

Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #472 on: April 12, 2014, 07:40:28 PM »
This just in from Marc AKA Powderman. I'm actually going to say I can't wait for Monday so that this can be on its way home  8)  The before pix are somewhere on top of this page, many thanks Nick for hooking me up with the correct MC and thank you Marc for doing your magic ;)



Here it is stripped and blasted and ready to coat:



And completed:




« Last Edit: April 12, 2014, 07:42:27 PM by edwardmorris »

Offline edwardmorris

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #473 on: April 14, 2014, 04:41:06 PM »
No luck with finding anyone in the WI area to pick up the oil screen, so I kept searching, eventually tracked down a Honda dealership all the way out in UT that still had three of the oil screens left. I bought them all just in case someone needs them around here. Came out to $28 each with the shipping, but still much better than $42 shipped that Yamiya and eBay were asking. One thing that pissed me off though, is the way the packaged them  >:( I was hoping to see some nice red labels.

Another dealership in WV had some unobtanium left, NOS OILhoses! I don't know if I should put these on my bike or sell them on eBay to add to the project fund. What do you guys think? Yamiya has an aftermarket set for almost $450 shipped  :o If the originals are worth more, I could use the money on the project...but these would look sooo nice on my bike too  :-\

Edit: OIL hoses, not brake hoses  ::)
« Last Edit: April 14, 2014, 09:18:50 PM by edwardmorris »

Offline Powderman

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Re: 1972 CB750 Four K2 -- Project "Ice Cream"-- ENGINE TEARDOWN
« Reply #474 on: April 14, 2014, 04:56:20 PM »
Your M/C went out today.