Topic: Sandcast #97 restoration

[CycleRanger]

As if you don't have enough to do......

http://cgi.ebay.com/ebaymotors/1969-70-Honda-CB750-Sandcast-K0-Early-Vin-Rare-Parts-/230545133635?pt=US_motorcycles&hash=item35ad8f9043

It's even in your state.

Wow, amazingly intact!

[Roach Carver]

I found that bike, and I posted it here. It hurt me deeply. cant wait to see it restored.

[markb]

Watching this one too!!!

Just a heads up....those Triple A floor boards are highly sought after parts. Alot of people are looking for them.

Oooops!  I guess I broke the #1 rule, DON'T THROW ANYTHING AWAY!.  Too late on these.  They were in really rough shape, bent, rusted, etc.  So hopefully I didn't throw away too much money.
Mark

[markb]

I found that bike, and I posted it here. It hurt me deeply. cant wait to see it restored.

Thanks for posting it, sorry if I took it out from under you.
Mark

[markb]

I’m about ready to pull the engine out of the frame.  Good time to inventory what I have and don’t have.  


Here’s the 19 liter tank all nicely painted.  Did I mention I was looking for a short-neck petcock?  Anyone?


Some of the other big goodies are:
Rolled rear rim


Double cut front fender




By the way, are the stays supposed to be straight?


2-hole rear fender (it appears to have a larger rolled edge that later fenders?)


I have the original carb bodies with the horizontal vent tubes (top).


I was lucky enough to pick up another early set complete with original (not repro) 28 tops, correct adjusters and rubber caps and a repro 5mm cable.


The top fork clamp is supposed to have a 23mm nose.  Not sure what that is.  Can someone explain that to me?


Smooth rubber oil lines.  I think they may be restorable.


Early brake caliper with knurled screws


Pointer-less kill switch knob control and master cylinder without oil level line


Early brake line fork with short neck oil lines.  Not sure if I’m going to be able to salvage them yet.


The frame is for a LH horn.  It that extra gusset for the steering damper?


Center stand without the gusset


Also I understand that the lower fork clamp, oil tank and swing arm are supposed to be date stamped for this vintage.  I’ve looked them over and found some numbers and letters but they don’t appear to be dates.  Any of you sandheads able to enlighten me?

[markb]

Now the missing stuff.

It was missing the brake pedal (early one without the stop screw), exhaust of course and left hand horn.  Over the summer I scored on NOS brake pedal and NOS LH horn.  For the exhausts I got a set of reproduction Lotus Roots with baffles (arguably the biggest visual item on the bike to have correct).  A group of us from the SOOC club got together and got Yamiya to make a bunch for us.  Thanks again to Steve Swan for helping make it possible.  By the way, there may be extras for those of you with VINs up to 4148.  I was missing the kick start and gear shift lever but some used ones that I’ll rechrome.

Other stuff I’m missing:
•   Short-neck petcock (high priority)
•   Front and rear footpegs with (I can find these)
•   146mm rear footpeg bolts (I can machine down the 148mm bolts and replate them)
•   11mm stem rear-view mirrors (high priority)
•   Recessed ignition switch (worst case I’ll borrow the one from my K0)
•   Ignition switch bracket (I can find one of these)
•   Finless oil filter cover (I have one with the fins turned off that I’ll use if I can’t find one)
•   2 hole air box without reliefs (I trying to find out if LPM can supply a cover without the inner holes drilled and I think the mounting brackets can be modified for an exact copy)
•   Side covers (worst case I’ll use my repros)
I’m sure there are some more little things that I’ve overlooked for now.

I’d still like to find:
•   More smooth rubber oil lines
•   Brake lines
•   Tach and speedo cables with the short knurled nuts
•   -040 harness (I’ve got an extra in pretty good shape)
I know some of these are probably impossible to find but if anyone has a “spare” tell me how much you need for it and we can probably make a deal. 

[markb]

Some of you might notice that there have been edits on my posts that contain pics.  I was just changing the source of the pics.
Mark

[markb]

A couple more notes before I forget.  Most of the hex bolts were big 8's with what appears to be a dull finish.  There were some exceptions.  The three bolts on the top fork clamp were flat and appeared to be chromed which I think is correct.  One oddity was the 4 bolts that bolt the front fender stay to the fork lowers.  No 8's and they look chrome too.  The other was the screw that holds the gauge rings together.  The early part book (7/69 I think) shows a phillips screw and mine was a no 8 chrome plate hex head.  Who knows if they're original.
Mark

[CB750faces.com (Lecram)]

My K0 had no. 8 bolts for the fender and a phillips screw for the gauge rings, which is conform the parts list. But my K0 is a late one

[zzpete]

  SUBSCRIBED!!

[pdxPope]

  SUBSCRIBED!!

+1!!


-JP

[The_Crippler]

Dude, you've got a treasure in the making here.

Okay, as mentioned, my knowledge of 750s is pretty much nil, so pardon the stupid question:  What is a "double cut fender"?

[Greggo]

Okay, as mentioned, my knowledge of 750s is pretty much nil, so pardon the stupid question:  What is a "double cut fender"?

Pretty sure that refers to both the front and back edges having that sharp/cutoff look like the one pictured.  Later fenders had rolled edges on the front.

[CB750faces.com (Lecram)]

Okay, as mentioned, my knowledge of 750s is pretty much nil, so pardon the stupid question:  What is a "double cut fender"?

Pretty sure that refers to both the front and back edges having that sharp/cutoff look like the one pictured.  Later fenders had rolled edges on the front.

right

There are also fenders with only at the front side a rolled edge and a scharp edge on the lower side

[vnz00]

Hi Mark,
The 23mm on the top triple refers to the width of the part that the gauge clamp screw goes into. If you hold the early triple nose up to the sandcast/k0 ones you will see it straight up.
My early sandcast has a chrome Phillips head screw, not a hex bolt holding the gauge clamps together. #8 bolts on the front fender, and the stays should be straight.

The middle airbox holes can be filled easily, and the brackets trimmed to be similar, but the width is not quite spot on, and the recesses in the back of the airbox will be the only real giveaway therethat it is not original.

The chrome hex heads u have may very well be original. The on the gauge clamps is an m4 or m5 not really interchangeable on any other bolt on the rest of the bike. Interesting. Are the brake banjo bolts chrome too?

Top triple bolts online were chrome and not #8's.

[markb]

Thanks Steven.
I measured mine and it actually 20mm.  A discussion on the SOOC forum seems to indicate that they were about 20mm and 23 mm.  Thanks for the info on the airbox.  I'm still looking for the 2-hole airbox but the other option might be OK until then.
Mark

[markb]

The engine is out.


I know this is a sandcast but I didn’t expect to see sand in the exhaust ports.  I think ants or some other insects were living in it.  I saw webs and dirt with tunnels in the intake rubbers.


The 3 screws on the breather cap wouldn’t come out (using an impact driver) without rounding them out.  They’ve be soaking for a week but it obviously can’t get to the threads.  I had to resort to drilling off the heads.  I use a ¼” drill and stop when the head pops off.


Then the cover came right off.


Fifteen of the valve cover screws came right out but I had to drill the last three.  With a little tapping with a soft hammer the cover came off.  Note the cross-hatch pattern on the inside of the cover.  I’ve never seen that before.


Now the bad news.  The valve train is quite rusted.  A good place to stop for the day (last night).  I soaked everything up real good and will let it sit overnight.  Hmmm.  I might have to look for a donor engine.

[754]

 Thanks for the excellent reference pics.

 I suspect that mabe a bit of chome/customizing took place. I say this because the brake junction appears to be polished and you say some bolts look chromed.

 I had # 572 with engine #700 or 701.. I looked and looked for the difference in the top tree, comparing it against another unicorn tree. I could not see the difference. Thanks for clearing that up, I did not have the instruments off.

 Take a look at your exhaust clamps and rear peg mounts, you should spot some difference..


..754..

[Stev-o]

Sad to see the inside of the motor like that.

[Damfino]

Now the bad news.  The valve train is quite rusted.  A good place to stop for the day (last night).  I soaked everything up real good and will let it sit overnight.  Hmmm.  I might have to look for a donor engine.

  Holy cow!

[markb]

The cam, rockers arms and cam holders are off.  I cut the cam chain so I could rotate the cam.  It’s going to get replaced anyway.  Hardest part was getting the 1-2 holder off.  I tapped on it for an hour.  I think it was more hung up in the stud holes than the knock pins.  Believe it or not I had one of the cam holder bolts snap off.  After I got the holder off it turned out with my fingers.


There is one bit of bad news though.  I discovered a crack in the 3-4 holder.  I’m thinking it might have happened when I tapped the rocker pins out.  They moved but they moved slow.  It might have been there before too.  Who knows.


Other than that, things didn’t look as bad as I thought they would.  Here’s the cam.


Closup on the cam lobes.  


And the rocker arms.  No rust on the working parts.


Then came the head.  I took off the rubber pucks (just might have to replace them) and took out the four special screws below them first (for those who don’t know always do these first).  They came right out.  At first I thought my socket wasn’t engaged because there was no resistance, on all four.  My guess is the PO tightened them first and then the main nuts and that’s why they were loose.  By the way, only one of the four had a Phillips drive.  Then I did the nuts in reverse tightening order and the special bolt on the rear side.  The head pulled right off.  Note the interesting stud layout for the cam holders.

 
The head looks pretty good too, considering how bad it could be.


Closer look


Even the cylinders didn’t look to bad.  I got her soaking now.  I’ll pull of the rotor cover next and see if I can turn it over in a couple of days.  Maybe I won’t need a donor engine.

[HondanutRider]

Keep at it Mark!  I'm pretty sure others have started with far worse.  (This is a special case to be treasured.)

[themotoworks]

wow... plusses for sandcast, but man, i've never... never... seen an engine in worse shape

[supersports400]

Hi,

Count me in on following this thread, I like to see how this will turn into something nice.

Jensen

[markb]

I haven’t had much time this week to work on the bike but in anticipation of trying to free up the engine this weekend I decided to give the cylinders another good soaking.  While I was wiping out the cylinders I noticed a 1.00 stamped on one of the pistons.  Ruh-roh.  A quick check revealed the same thing on the others.  I measured the bore to make sure but yes they are oversize pistons.  I almost had to laugh.  Cylinders 2 & 3 are down and the cylinders don’t look to bad.  Numbers 1 & 4 don’t look so good from what little I can see.  So maybe I’m thinking too far ahead here but assuming the worst and the cylinders are not good what are my options?  Replace the jugs, resleeve and rebore to stock, or go bigger yet (is that possible)?  Either way I replace the pistons.  Keeping in mind a fairly exact restore, is an oversize bore acceptable?  I’d like opinions guys.  One more question, anyone ever split the case, remove the bottom of the connecting rods and pull the cylinder with the pistons in place?
Thanks,
Mark