Topic: Sandcast 4286 Project

[Greggo]

Guessing you werent able to check compression. Are you going to tear down further?

Got to...for paint.  I want to see inside anyway to check the primary tensioner, and the crank bearings.  If I can get away with just new rings for the pistons, I'll be happy, but we have to measure.

[Prospect]

Stev-o, here's a pic of a later cylinder, where you can see on the bottom side, the extra bolt hole, and the difference in the area surrounding it.  I'm lucky these are still on my motor...the last set that sold on ebay went for over $700.  I wish I wish I could find the right head before I button this thing up. 

Don't the K0's have the same thing? I can't remember now.

[Greggo]

Stev-o, here's a pic of a later cylinder, where you can see on the bottom side, the extra bolt hole, and the difference in the area surrounding it.  I'm lucky these are still on my motor...the last set that sold on ebay went for over $700.  I wish I wish I could find the right head before I button this thing up. 

Don't the K0's have the same thing? I can't remember now.

They got the extra boss around 15xxx, and it seems like they started getting drilled at around 20xxx, so lots of K0's came from the later mold.  It's a very subtle difference with the head still on, you can see the extra material where the bolt threads into if you look straight into the fins where the cam chain tunnel runs from the front of the motor.  The later heads are much easier to spot than the cylinders.

[01Thomas]

Hi Greggo

Please explain what is a "original 10mm crank"?

cheers
Thomas

...I just hope it has the original 10mm crank, and it doesn't need replacing/extensive work.

[Greggo]

Hi Greggo

Please explain what is a "original 10mm crank"?

cheers
Thomas

...I just hope it has the original 10mm crank, and it doesn't need replacing/extensive work.

This info:

crank shaft has 10 mm threaded hole for rotor fixing bolt, E1-E1080 (12 mm, 1081-onward)

Is from here: http://cb750sandcastonly.com/smf_forum/index.php?topic=217.0 which is a great place to learn about all the little differences in the early bikes.

[01Thomas]

Ah, OK, I've got it.

Question: Did the  threaded hole in the end of the camshaft ever change?

Hi Greggo

Please explain what is a "original 10mm crank"?

cheers
Thomas

...I just hope it has the original 10mm crank, and it doesn't need replacing/extensive work.

This info:

crank shaft has 10 mm threaded hole for rotor fixing bolt, E1-E1080 (12 mm, 1081-onward)

Is from here: http://cb750sandcastonly.com/smf_forum/index.php?topic=217.0 which is a great place to learn about all the little differences in the early bikes.

[Greggo]

Ah, OK, I've got it.

Question: Did the  threaded hole in the end of the camshaft ever change?

Hi Greggo

Please explain what is a "original 10mm crank"?

cheers
Thomas

...I just hope it has the original 10mm crank, and it doesn't need replacing/extensive work.

This info:

crank shaft has 10 mm threaded hole for rotor fixing bolt, E1-E1080 (12 mm, 1081-onward)

Is from here: http://cb750sandcastonly.com/smf_forum/index.php?topic=217.0 which is a great place to learn about all the little differences in the early bikes.

Not as far as I know. 

[Greggo]

The deeper I get into this motor, the happier I am...the pistons look almost brand new, and it turned over like a dream with the alternator bolt...the kick lever not so much, so I'll see if I have problems there eventually.  After about twenty minutes of tapping, razor-blading the gasket, then finally giving up and using a gigantic pry bar at the starter motor and cam tensioner mount (the one place Hondaman says it's safe), I freed the cylinders from the cases.





I got everything required to split the cases, and I stopped before flipping it over and undoing the bottom case bolts...top bolts are off.  I forgot to take pictures, but the tensioner rubbers look BRAND NEW...there was barely one little wear mark on the slider, and the wheel was not chewed up at all.  I've decided to use the new Cyclex parts, and save these nice used ones for another motor.  It looks as though someone rebuilt the motor with the .50 pistons, and barely put any miles on it.  This may turn out to be a really simple refresh for this motor



In other news, the painter sent back the battery tray so I could decide on the gloss level...it's perfect, so he'll get started on the rest soon.

[Stev-o]

Good news!

[Greggo]

Good news!

Yep, good news all around. Just got off the phone with the painter, and all the black and clear coated parts will be done next week!

[toytuff]

Moving right along! 

Nice to get a break and stop the doubt when doing these things. 

Quite the project and fine work to say the least.

tt

[Stev-o]

Quite the project and fine work to say the least.

+1....very impressive [and not in the CB450 kind of way!]

[Greggo]

Moving right along! 

Nice to get a break and stop the doubt when doing these things. 

Quite the project and fine work to say the least.

tt

Quite the project and fine work to say the least.

+1....very impressive [and not in the CB450 kind of way!]

Thanks guys   It's taken a lot of effort just to get this far.  Once I get the fasteners zinc plated, and the cases painted, this thing will really start looking like a bike again.

[toytuff]

Everyone here that has "gotten deep" into these bikes know all to well the work involved. I have yet to get into the motor (knocking on wood)  thing but very impressed with the work you and others do.

I'm ready to send Hondaman an invite just to learn from him.  (winters are wonderful) Of course it would take a month or two. 

tt

[Greggo]

Everyone here that has "gotten deep" into these bikes know all to well the work involved. I have yet to get into the motor (knocking on wood)  thing but very impressed with the work you and others do.

I'm ready to send Hondaman an invite just to learn from him.  (winters are wonderful) Of course it would take a month or two. 

tt

I only go as deep into 'em as I need to tt.  Frankly, I wish the last guy had painted it the right color, and done a half decent job on it so I could just clean it up and be done.  Instead there's 2mm of nasty looking glossy black paint slopped on in most places


In other news, the guys in the HiPo section told me the cam is stock It's in good shape too, so it'll go back in.  Maybe I should get a 16 toother and get a taste of what the very first 750's were really like

The original front 19 inch rim had really dull chrome, didn't match the nice 18 inch rear I found to replace the Harley wheel the bike came with, and I wanted to avoid having to re-chrome both to get a matching set.  So, I found a real nice K0 front for $90 shipped off ebay (Mrmonkeyclaw).  It was complete with the hub, so I unlaced it today, and polished up the hoop.  I now have matching K0 rims that I won't have to re-chrome.  It would have been nice to find a rolled rear rim, but the prices I've seen them going for don't seem reasonable.  Also just snagged a set of K0 chain adjusters for $25 shipped, and I'd been waiting a while for a deal on those   Time to buy some spokes before the hubs are done!

[toytuff]

Sweet!

tt

[Stev-o]

Hoops look great, Greggo. Where ya getting spokes?

[Greggo]

Hoops look great, Greggo. Where ya getting spokes?

CB750Supply, if they have the yellow zinc nipples.

[HondaMan]

Wow, Greggo, this is going great! I like to come and read your thread when I'm stuck at work, makes me feel better about mine sitting under the back patio roof at home, all alone... 

[Greggo]

Wow, Greggo, this is going great! I like to come and read your thread when I'm stuck at work, makes me feel better about mine sitting under the back patio roof at home, all alone... 

That's funny Mark, because sometimes when I'm stuck at work, I read through your book to help me through this project   I've been reading through the Engine Inspection section very carefully the past few days! 

Did you ever end up making the K0 style rocker shafts available?

[HondaMan]

Wow, Greggo, this is going great! I like to come and read your thread when I'm stuck at work, makes me feel better about mine sitting under the back patio roof at home, all alone... 

That's funny Mark, because sometimes when I'm stuck at work, I read through your book to help me through this project   I've been reading through the Engine Inspection section very carefully the past few days! 

Did you ever end up making the K0 style rocker shafts available?

Yes, I have a few of them, maybe 4 sets?

[Greggo]

Wow, Greggo, this is going great! I like to come and read your thread when I'm stuck at work, makes me feel better about mine sitting under the back patio roof at home, all alone... 

That's funny Mark, because sometimes when I'm stuck at work, I read through your book to help me through this project   I've been reading through the Engine Inspection section very carefully the past few days! 

Did you ever end up making the K0 style rocker shafts available?

Yes, I have a few of them, maybe 4 sets?

Sent you a message on those Mark. 

[Greggo]

More check-marks off the list:

PeakMoto:
Good tapered steering bearings

CB750Supply:
Fork gaiters
Rear brake shoes
Spokes
Front wheel seal
 
From Yamiya:
K0 engine gasket set
Rear shock top nuts and bottom bolts and other screws & washers
Engine screw kit
Chain case mounting kit
Battery box top rubbers (x4)

I saved $7 by using paypal with Yamiya, I guess because their exchange rate was favorable today.

Splitting the cases this weekend, hopefully that won't cost me anything

[Stev-o]

Sounds like it was an expensive day.

[Greggo]

Sounds like it was an expensive day.

Just got a lot worse...or better