Author Topic: gravygrabber's 70 CB750 project (Read 5985 times)

gravygrabber · « **on:** March 26, 2013, 09:39:12 PM »

Hi everyone,

I started this thread to post about my project CB750. It all started with this thread, http://forums.sohc4.net/index.php?topic=118999.0

As of today the bike is on my rack and I'm getting ready to evaluate what it needs and what to do with it. Ideally I would like to make it as stock as possible with maybe some tasteful mods that do not radically change the classic look of a CB750.

I have to be honest this bike is not in good shape. I don't think it's the best example to start with but I got a good deal on it so I'm going to attempt to set it right.

Here's some more pictures. Please feel free to make comments on what you see or don't see. Hopefully this is a start to something good!

Didn't notice this until it was on the lift but at least 2 spokes on the rear wheel are broken. Anyone know if the hub is original or Harley?

Pretty Jenky wiring here. I have a new repro harness but it doesn't look exactly the same on the plugs/terminals. Anyone run into this?

754 · « **Reply #1 on:** March 26, 2013, 09:48:13 PM »

Looks like 16 inch rim laced to stock hub.

gravygrabber · « **Reply #2 on:** March 26, 2013, 09:48:13 PM »

Is this airbox off an "F" model CB750? Maybe that's why it doesn't want to fit on the carbs?

gravygrabber · « **Reply #3 on:** March 26, 2013, 10:27:17 PM »

I have no clue what this is

gravygrabber · « **Reply #4 on:** March 26, 2013, 10:32:46 PM »

This oil gauge has no lens...Not sure if that can be fixed. It does work though

gravygrabber · « **Reply #5 on:** March 26, 2013, 10:42:13 PM »

Is this tail light correct for a KO??

gravygrabber · « **Reply #6 on:** March 26, 2013, 10:52:10 PM »

These gauges correct for a KO?

Data plate is odd as it has no VIN# stamped on it. Also has something covering the right top corner so I can't see the month/year

The vin# looks low though

gravygrabber · « **Reply #7 on:** March 26, 2013, 10:57:16 PM »

What's broken here on the lower triple tree?

SOHC4 Cafe Racer Fan · « **Reply #8 on:** March 26, 2013, 11:20:12 PM »

Quote from: gravygrabber on March 26, 2013, 10:57:16 PM

What's broken here on the lower triple tree?

That's the steering lock.

gonzobrian · « **Reply #9 on:** March 27, 2013, 05:31:01 AM »

Well the frame is from a sandcast. What is the engine number? Also the vin plate is correct. The early K0/sandcast did not have a vin number or date of manufacture.

Garystratos201 · « **Reply #10 on:** March 27, 2013, 05:48:38 AM »

This should be interesting. Is it running or locked up ?........Gary

iron_worker · « **Reply #11 on:** March 27, 2013, 07:19:30 AM »

Quote from: gravygrabber on March 26, 2013, 10:27:17 PM

I have no clue what this is

That would be your speedo cable. Hooks up to a little gearbox on the front axle.

...either than or tach drive. There is a raised section on the right side of the valve cover where it hooks in.

*edit* I saw your pics in the main gallery and it is definitely your tach drive. *edit*

You've got a real mess on your hands there. ha

IW

Frankensteins Bride · « **Reply #12 on:** March 27, 2013, 07:43:50 AM »

Ooh looks like a fun basket case to bring back to life! I'll be watching!

SOHC4 Cafe Racer Fan · « **Reply #13 on:** March 27, 2013, 07:57:54 AM »

Be prepared to spend a hefty amount of coin on this project. Especially if you are going for a restoration. If its more of a rat bike survivor look, or cobbling different year parts together, that's much less financially draining. Sandcast parts are pricey.

Garystratos201 · « **Reply #14 on:** March 27, 2013, 08:16:01 AM »

Dont get discouraged just take your time and do what finances will allow. You can always improve after it becomes rideable.........Gary

Bankerdanny · « **Reply #15 on:** March 27, 2013, 09:34:58 AM »

I would be interested in an opinion from the sandcast guys. Since this frame is inside the sandcast range, might it not be worth while to sell the frame to someone with a sandcast engine (I know there are a couple of people here that have them).

Given the premium that the very early bikes fetch I would think that the frame alone is worth more than he paid for the who bike.

gravygrabber · « **Reply #16 on:** March 27, 2013, 05:30:14 PM »

So is it titled wrong as a 70?
Engine number is early die cast for those that didn't see my first thread.

Vinhead1957 · « **Reply #17 on:** March 27, 2013, 06:17:36 PM »

Isn't the cutoff for the 69 year around mid 7000 so it would be a sandcast 70'

gravygrabber · « **Reply #18 on:** March 27, 2013, 10:55:20 PM »

Quote from: Vinhead1957 on March 27, 2013, 06:17:36 PM

Isn't the cutoff for the 69 year around mid 7000 so it would be a sandcast 70'

Frame or engine?

gravygrabber · « **Reply #19 on:** March 28, 2013, 02:02:50 AM »

Quote from: Garystratos201 on March 27, 2013, 05:48:38 AM

This should be interesting. Is it running or locked up ?........Gary

Not locked up. It fired up for a second already but the wiring is screwed up bad. The starter stays on too only way to turn it off is with the key. Need to figure that out next then start again.

754 · « **Reply #20 on:** March 28, 2013, 07:36:27 AM »

Disconect starter and kick it. You can bypass all electrical,by wiring from battery to coils, to s if the motor runs ok..

Bankerdanny · « **Reply #21 on:** March 28, 2013, 10:04:28 AM »

I think back in the day some states titled based on when the title was first issued vs when the vehicle was built. Once the title showed 1970 it stuck.

gravygrabber · « **Reply #22 on:** March 28, 2013, 11:08:17 AM »

Okay so that's good news I guess thanks

As far as the back wheel goes do I just need a NOS wheel, clean up the hub and relace?
The steering lock on that triple tree. Is it broken? How hard are those to find are they specific to KO bikes and sandcasts?

Dream750 · « **Reply #23 on:** March 28, 2013, 02:27:04 PM »

Since your original wiring has been *compromised* by the PO, perhaps using a temporary or shortcut wiring diagram will help get you up and running a bit sooner.
http://www.hondachopper.com/garage/simple_wiring_diagram/simple_wiring_diagram.html

Later on, you can install your new repro wiring harness after getting sorted out and evaluated.

754 · « **Reply #24 on:** March 28, 2013, 02:57:22 PM »

You may be able to use your hub,check if it is a2 hole hub, if it is you may want to weld theareas wornby the spokes. To check, pull off brake plate look inside you will see two or four holes.. Approx 7/8 inch diameter..

Stev-o · « **Reply #25 on:** March 28, 2013, 05:55:39 PM »

Quote from: Bankerdanny on March 28, 2013, 10:04:28 AM

I think back in the day some states titled based on when the title was first issued vs when the vehicle was built. Once the title showed 1970 it stuck.

Danny, what you're saying is titles were issued when bikes were sold so a '69 model could have a '70 title.

SOHC4 Cafe Racer Fan · « **Reply #26 on:** March 28, 2013, 08:55:31 PM »

I have a 1973 CB750K2. Build in mid 72 but first titled in 73.

Bankerdanny · « **Reply #27 on:** March 29, 2013, 10:25:04 AM »

Stev-o, yes, that's what I'm saying.

stewonepot · « **Reply #28 on:** March 30, 2013, 10:25:30 AM »

The frame and log book(reg doc) for my 76 cb750 was first reg in 78 in the uk. I don't think they had sold all of the f1's when the f2's came out! nos!
Regards Stew.

gravygrabber · « **Reply #29 on:** March 30, 2013, 10:44:35 AM »

I haven't had any time to start on this bike but I did spare a couple hours and picked up an 80's GoldWing in running condition for $500 yesterday. Looks like I'll have another bike to play around with too.

gravygrabber · « **Reply #30 on:** December 08, 2013, 07:58:20 PM »

I'm starting to get back into this bike again. I rebuilt the Goldwing I mentioned in the last post and sold it on so it has a new life. Now back to this bike.

Bankerdanny · « **Reply #31 on:** December 09, 2013, 02:15:15 PM »

Welcome back to the fray.

gravygrabber · « **Reply #32 on:** December 09, 2013, 06:12:51 PM »

I think to keep myself involved I will commit 30-60 mins. a day to this project (hopefully) I work as a full time auto tech so I have only so much time to put in. I'm going to push this one in tonight and rack it up and get back to it.

gravygrabber · « **Reply #33 on:** December 09, 2013, 09:18:33 PM »

Okay so I moved my Harley off the rack and went outside for the K0. It's like 5 degrees outside and the rear brake is stuck on.....I grabbed a rubber mallet and beat on it a little and she loosened up. Pushed her in and racked it. Lifted it up and the damn cylinder seal is got a leak now. Damn it! Rack isn't even a year old....Gotta call Handy in the AM and see what they will do I guess. Still lifts up fine just a little noisy. I set the lock and dumped all the air so whatever it's good for now.

So I've never took on such a big project. Any suggestions for this one? Should I fix it enough to start it then tear it down and build it back up?

A little background, got this bike from a co-worker when I worked at Honda. He wasn't a tech but tried his best to get this thing going. He brought it to the shop and an old tech that worked on bikes before Honda went into the car business supposedly helped him put it back together and set the timing, etc.. I think he re-ringed it and had the cylinders honed and replaced a bunch of studs. I don't know but a bunch of screws are hacked the thing leaks oil pretty fast when you crank or attempt to start it so I know something wasn't put together correctly. I want to strip it completely down to the case halfs, inspect and replace/repair as needed and then paint and re-assemble. I don't want to worry about what was done by the PO I want to KNOW for myself. He said the owner before him drag raced it and modded it, etc.. :/

I would like to find and put the correct K0 parts on this bike. I don't care how long this takes I want it to be "right"

Anyway this is how it sits today

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Cragdog · « **Reply #34 on:** December 10, 2013, 02:10:40 PM »

Cool project, nice frame number too. It'll be interesting to see how you bring this back to life. Subscribed!

gravygrabber · « **Reply #35 on:** December 10, 2013, 06:49:29 PM »

I think the bike should be fully thawed out tonight

I think I'll try and get it to run at least first. Is it bad for the engine to run it without pipes? I have a beat up pair of RC pipes that came with it but I'm lazy and don't want to throw them on just for a 10-15 second engine run.

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Author Topic: gravygrabber's 70 CB750 project (Read 5985 times)