Topic: Sandcast #97 restoration

[the technological J]

well this certainly wouldnt be a book mark....... what kind of pet cock does a 73 tank have?

[Magpie]

Yes, I had to take the con rods off the crank and remove the cylinders, pistons and con rods in one piece. I then pressed the pistons out with a 10 ton press. They made a hell of a bang when they released from the cylinders. The press had a fairly small end on it so we used a caliper piston on it to spread the load a bit. Be sure to mark which piston came from which hole, it helps to match the conrods to the journal they came from.
If you want an exact restore then you need a new set of cylinders, pistons and rings for an as new cylinder size. I for one could care less if it's an overbore. It's a rebuild of a motor and if it needs to be done so be it. You are the one to decide how exact you're restore will be but I think that's going above and beyond. I have a K0 and a sandcast motor that are .25 over because it was required to make it run and restore the bores. If someone is going to find fault with that then that's their problem. I have never been asked it it's a stock bore size. I know the sandcast only people are really uptight about about being 100% correct but there is a point to draw a line I think. An overbore is inside the line in my opinion.
Rant over and I'll pour a little more wine. You're doing a great job and I'm watching and learning.
Cheers,
Cliff.

[seaweb11]

I'm in for the ride.

It is good of you to restore and take guardianship of this piece of history
 

[markb]

well this certainly wouldnt be a book mark....... what kind of pet cock does a 73 tank have?

Here's some pics I borrowed from the SOOC site.
The one on the left is the early short neck used on sandcasts up to VIN 1937.  The one on the right is the later one.


This is the short neck.  Note how it tucks up under the bottom edge of the tank.


This is the later one I believe is used up to at least the K2's and probably up to K6's.

[Toxic]

I'm always amazed at how knowledgeable and precise the "sandcasters" can be.

[markb]

Well, things aren't getting much better.  I got the transmission cover off OK but wasn't happy with what was underneath it.  I guess that's what I should expect.


I've got all the screws out on the rotor cover but one.  It's stuck part way out.  I was hoping if I could loosen up the cover I could get some rust loosener down by the threads.  I wonder if this is the hole with the pin.  I soaked all around the gasket edge hoping that will loosen it up.  I've got a funeral to go to now so I'm going to let her soak.

[Greggo]

Yikes!

[754]

 The shift drum parts are important and different on the early ones.
 That cover bolt, keep running it in and out, a small section is galling, and if you do not work it loose, it WILL pull out the rest of the thread.. be patient..

 Do you have measuring tools to measure the cam? Would like to know the lift & find out once and for all if the early ones have hotter cams.. or is just a myth?

 If you guys think this motor looks bad inside, dont even think about tackling a 50s or older bike..

[CB750faces.com (Lecram)]

That looks bad. But I think that is is restorable.

If you need these parts, I have these. Let me know if you want them, both NOS:

[egar]

Mark,

Welcome back. Will be watching. Sent you a message about parts I'm looking for to finish my KO.
I haven't posted in a while, but you've inspired me to show my progress....

Ed

[markb]

Lecram,
Thanks for the offer.  Once I get the whole engine apart I'll have to access what all I'm going to need.  I'll certainly keep you in mind.

egar,
I sent you a message about the parts you're looking for.  Sorry but I'm not able to help with those.  Checked out your thread.  It looks like it's coming along great.  Good luck.

Mark

[Greggo]

Did you get that screw to give yet??

[Old Scrambler]

I'm putting my feet up................You have a nearly identical condition to the K1 I just rescued from the local swamp.

Mark.........I have a very low mile late K0 motor with K1 features and 2 other K1 motors if you need whole or parts.  Also, that short petcock is very similar to a CL77 petcock. The fuel line feeds are repositioned as reflected in the original casting. You may be able to tap the CL77 body and then cut and weld the feeds at the correct position.

No steering dampner that I recall..............should the clutch cable be gray?  If so, I may have one or two.

[markb]

Warning: some of the following photos are graphic and are not for everyone.

It took a while but I got the rotor cover off.  Didn’t want to break this one.  Not pretty inside.  Had to cut the head of the screw off to do.  It still doesn’t want to come out.  More soaking and more heat and try later.


The clutch cover actually came off quite easy.  More horrors though.


Flipped her over and got the pan off not too much trouble.


Here’s the top half.  The cases split too without much trouble although the countershaft bearing holder was a PITA.


And the bottom half.


Close up on the gears…


…and the other half.


They look bad but actually I don’t think there as bad as they look.  After wiping off some the “gunk” on the surface there’s shiny teeth underneath.  I need to get everything apart and inspect everything more closely but I hope and can save most of it.

[Stev-o]

Graphic indeed! Where was it stored?
Almost looks like the motor was under water! [actually may be have been in better shape if it was!]

[Greggo]

I can't wait for the before and after pics...I think there should be a before-and-after pics of the month vote  

[markb]

Graphic indeed! Where was it stored?
Almost looks like the motor was under water! [actually may be have been in better shape if it was!]

On the SOOC site I said that the seller said it was a barn find.  I commented that it must have been behind the barn... in the pond behind the barn.

I can't wait for the before and after pics...I think there should be a before-and-after pics of the month vote  

You might have to wait.  This one's going to take awhile.

[CB750faces.com (Lecram)]

Graphic indeed! Where was it stored?
Almost looks like the motor was under water! [actually may be have been in better shape if it was!]

On the SOOC site I said that the seller said it was a barn find.  I commented that it must have been behind the barn... in the pond behind the barn.

I can't wait for the before and after pics...I think there should be a before-and-after pics of the month vote  

You might have to wait.  This one's going to take awhile.

You have a tough job to do, but when you have finished the restoration you will be very very proud of it.

BTW: what is the SOOC site?

[markb]

SOOC is the Sandcast Only Owner's Club.  Enormous amount of info for sandcasts.  Here's the site:
http://cb750sandcastonly.com/
Here's a link to my thread there.
http://cb750sandcastonly.com/smf_forum/index.php?topic=366.0
I lot of my posts are the same on both sites but the feedback is different.

[markb]

I forgot to mention there was some good news.  The nuts on the con rods came right off and I pulled the crank out.  Number 2 & 3 pistons slid right out by hand without much force (they were at the bottom) and they look great.  The seller did say that it had been rebuilt before it was parked (abandoned) and it doesn’t look like it had been run much after the pistons were put in.  The rings were loose and no carbon on them.  Both 1 & 4 are loose but didn’t want to come out yet.  I wasn’t going to force it.  I’ll soak them for a couple more days.  Still working on getting the jugs off too.  If the cylinder ends up looking OK I’m considering using it and the oversize pistons.

[HedNut]

Wicked collection of rust inside that mill!... I bet it's 90% surface and will come away gleaming with some good efforts put into her!

You know what else is nifty....before I replied to this thread you were at 69 posts!! OH YEAH!!  Twas Kinda fitting if I do say so myself...

Keep up the good work..it's a very exciting build!  I can't wait for the next step!

[markb]

I went to take another stab at getting the cylinders off.  Maybe it’s my imagination but it seems that the top machined surface of the cylinders is closer to the top fins than I remember.  I’m not sure how well this photo shows it but the machined surface is barely higher than the fins.  Is it possible this surface has been machined?  Anyone have a cylinder that they can accurately get a dimension from the top machined surface to the bottom surface where it sets on the case?  Or better yet, the depth of the two counterbored holes on the rear, center studs?  They seem shallow to me too.
Thanks,
Mark

[MoMo]

Mark, I have a cylinder somewhere in my shop but it is from a 77, probably not be of any help but I can dig it up  and measure if you think it'll be of any help to you, Larry

[markb]

I'd be pretty sure that anything up to about a K1 or K2 would be the same.  Not so sure on the '77.

[markb]

Does it have the small hole crank, early should have  smaller alternator bolt threads.

I did note that the rotor bolt had a 17mm hex head.  Haven't removed it yet but shouldn't the small bolt (10mm) have a 14mm hex head?  Would that mean that the crank has been replaced?