Author Topic: My 1978 CB750K Project (Read 2448 times)

Bucanneer · « **on:** October 03, 2011, 08:09:04 PM »

Hi.

I recently bought a 1978 CB750K that had been converted into a "bobber." it came complete with a Harkey tank and flying eyeballs. Topping things off, someone decided that the German Iron Cross was a fitting symbol and so fitted this symbol upon the replaced oil tank, on the gas tank, the air stems, etc. To each his own.

I have been taking extensive pictures, in the next post you will see the bike in its "original"unadulterated, wholesome goodness.

This is my winter project, and I plan on photo-documenting it the whole way.

Next stop? Frameville.

Bucanneer · « **Reply #1 on:** October 03, 2011, 08:20:30 PM »

Here is photographic evidence of what can be purchased for $800.

Gpreciado · « **Reply #2 on:** October 03, 2011, 08:23:23 PM »

Not bad, do you plan on keeping it a bobber or are you going to look for a frame to start from scratch? Either way I would ride the he'll out of it.

Welcome to the site

Bucanneer · « **Reply #3 on:** October 03, 2011, 08:23:47 PM »

And some more pictures.

Bucanneer · « **Reply #4 on:** October 03, 2011, 08:32:13 PM »

Chipping away.

Bucanneer · « **Reply #5 on:** October 03, 2011, 08:37:18 PM »

I am going to strip everything off, clean up the frame a bit and have it powder-coated. While that's going on, we'll start tearing down the engine and transmission. I've purchased a parts bike (another 78 750K) and will be using that where needed. I've also purchased new wiring harness (this one is *shot*), and host of other goodies that will appear as the snow begins to fall here in Hutchinson, MN.

I'm really looking forward to this project, and to getting everyone's opinions along the way.

Back to the shop!

Free Booter · « **Reply #6 on:** October 03, 2011, 09:25:52 PM »

Kinda reminds me of what Architect started with.

KB02 · « **Reply #7 on:** October 04, 2011, 08:24:19 AM »

...wow...

poor bike...

Good luck. I'll be watching. It will be interesting to see what you come up with in the end.

Bucanneer · « **Reply #8 on:** October 07, 2011, 11:14:49 AM »

More Progress & Seat

NP3 · « **Reply #9 on:** October 07, 2011, 12:17:04 PM »

Welcome! I've recently picked up a '78 CB750k as well. I think my wiring is pretty beat too. I've done a little digging to find a new harness, but haven't been able to track anything down. Where did you pick up your wiring harness from?

Also, does anyone have a good source for K8 parts. I know I'm preaching to the choir, but I spend a ton of time trying to hunt down various parts. Hopefully, you guys can save me some time here and I can return the favor sometime down the road.

Bucanneer · « **Reply #10 on:** October 08, 2011, 07:41:13 AM »

Quote from: NP3 on October 07, 2011, 12:17:04 PM

Welcome! I've recently picked up a '78 CB750k as well. I think my wiring is pretty beat too. I've done a little digging to find a new harness, but haven't been able to track anything down. Where did you pick up your wiring harness from?

Also, does anyone have a good source for K8 parts. I know I'm preaching to the choir, but I spend a ton of time trying to hunt down various parts. Hopefully, you guys can save me some time here and I can return the favor sometime down the road.

I actually have a NOS 78 wire harness for this project, but you can find them on eBay. I use eBay a lot. Also, an often overlooked source of NOS is your local Honda shop - some shops belong to a website (I don't remember the name) that let's them list their stock and see other's in return. You'd be surprised what you can find.

Bucanneer · « **Reply #11 on:** October 08, 2011, 07:47:57 AM »

Quote from: Gpreciado on October 03, 2011, 08:23:23 PM

Not bad, do you plan on keeping it a bobber or are you going to look for a frame to start from scratch? Either way I would ride the he'll out of it.

Welcome to the site

Gracias - I didn't see your response between the pics. I'm not going to keep it a bobber. I'm going to grind off the pieces/parts that were put on to make it a 'bobber' and weld a loop on for a seat. I haven't decided exactly what I'm going to do, but several aspects are already in the works.

This weekend, I'm finally pulling the engine out and starting the frame cutting and grinding and might even get to a little bondo action. We'll see.

Bucanneer · « **Reply #12 on:** October 10, 2011, 07:57:38 PM »

Tonight I was able to get the engine out of my frame. We have beams in the basement in the ceiling - perfect for ratchet straps. Or so I thought.

I positioned the bike on the bike lift/jack. And then I positioned a hydraulic table next to it. Then I fitted the straps. I put one strap on the back of the engine and one strap on the front. I little ratchet there, a little ratchet there and all was going quite well.

I was able to slowing inch the engine out on to the table and was very proud of myself.

I was upset though, because the vinyl mat had been lost in the process. So I figured the straps worked before, they should work again.

And they sure did. The engine slid right off the damn table because, although I centered the table underneath the attachment points, my basement floor isn't level....

Oh well, I'm rebuilding it anyway. (remarkably, there was no damage)

I was also able to cut off some of the harley tank mounting tabs and the rear foot peg/exhaust supports.

Pictures to come - with an engine on the floor. I'm too tired to lift the damn thing back onto the table.

!

(don't they sell these things new or something I read about?

)

lucky · « **Reply #13 on:** October 10, 2011, 11:31:17 PM »

Quote from: NP3 on October 07, 2011, 12:17:04 PM

Welcome! I've recently picked up a '78 CB750k as well. I think my wiring is pretty beat too. I've done a little digging to find a new harness, but haven't been able to track anything down. Where did you pick up your wiring harness from?

Also, does anyone have a good source for K8 parts. I know I'm preaching to the choir, but I spend a ton of time trying to hunt down various parts. Hopefully, you guys can save me some time here and I can return the favor sometime down the road.

You can get a brand new harness 1975 and it will work just fine. Very little difference.
That way you will have all new wiring that all plugs together.
So just keep ordering 1975 electrical parts. It will all work together.
You can check your workshop manual and compare wiring diagrams and you will see what I mean.

Bucanneer · « **Reply #14 on:** October 11, 2011, 07:55:54 AM »

Removed the rear foot rest and exhaust support and got the engine out.

Bucanneer · « **Reply #15 on:** October 22, 2011, 10:21:32 PM »

Question for everyone out there (and I've been looking through the history) - I've pulled the forks apart, and will need to replace many parts.

Has anyone used a different setup here, perhaps one that offers adjustable pre-load/damping/etc? I've done some searching on what would work with the 35mm stock fork diameter, but was hoping someone could share some experiences.

Thanks in advance.

More pictures coming - frame almost ready for sand blasting and powder coating!

theofam · « **Reply #16 on:** October 25, 2011, 09:57:04 AM »

Check out Race Tech's Cartridge Emulators. I've heard they work great for our damping rod forks.

http://www.racetech.com/HTML_FILES/EMULATORGV.HTML

lucky · « **Reply #17 on:** October 25, 2011, 11:23:54 AM »

Quote from: NP3 on October 07, 2011, 12:17:04 PM

Welcome! I've recently picked up a '78 CB750k as well. I think my wiring is pretty beat too. I've done a little digging to find a new harness, but haven't been able to track anything down. Where did you pick up your wiring harness from?

Also, does anyone have a good source for K8 parts. I know I'm preaching to the choir, but I spend a ton of time trying to hunt down various parts. Hopefully, you guys can save me some time here and I can return the favor sometime down the road.

I have a 1978 CB750K also.
When it came time for the wiring harness there were none.
So what I did is I converted to the 1975 wiring harness instead. Those ARE available.
Everything fits . There could be some minor thing but so far all the important things plug right in. IT all matches.

Bucanneer · « **Reply #18 on:** October 26, 2011, 11:23:59 AM »

Quote from: theofam on October 25, 2011, 09:57:04 AM

Check out Race Tech's Cartridge Emulators. I've heard they work great for our damping rod forks.

http://www.racetech.com/HTML_FILES/EMULATORGV.HTML

Thank you.

liPPy · « **Reply #19 on:** October 28, 2011, 10:52:58 AM »

Quote from: lucky on October 25, 2011, 11:23:54 AM

Quote from: NP3 on October 07, 2011, 12:17:04 PM
Welcome! I've recently picked up a '78 CB750k as well. I think my wiring is pretty beat too. I've done a little digging to find a new harness, but haven't been able to track anything down. Where did you pick up your wiring harness from?

Also, does anyone have a good source for K8 parts. I know I'm preaching to the choir, but I spend a ton of time trying to hunt down various parts. Hopefully, you guys can save me some time here and I can return the favor sometime down the road.

I have a 1978 CB750K also.
When it came time for the wiring harness there were none.
So what I did is I converted to the 1975 wiring harness instead. Those ARE available.
Everything fits . There could be some minor thing but so far all the important things plug right in. IT all matches.

Can you elaborate? Wiring my K8 looms large on the horizon and I've been dreading it as my harness has been chopped to hell.

I've longingly admired the new harnesses on Parts n More but always assumed they just wouldn't work on a 1978 750.

What specifically do you have to modify?

Thanks!

lucky · « **Reply #20 on:** October 31, 2011, 07:50:32 PM »

Just take the old harness completely out.
Do not throw it away because you might need a certain color of wire with stripe on it. Throw it in your wiring parts drawer.

Get a honda workshop manual (Clymers) with CB750 wiring diagrams.
Use the K5 diagram.

You can compare the wiring diagrams.
Anyway just get that wiring harness from Part-N-More.

Then the EMGO ignition switch plugs in.
Get the Regulater/Rectifier from Rick's in Washington.
Get a new OEM Fuse box. Plugs right in.
Just start matching up wires and components.

Put the components in place THEN start connecting it all together.

Even the engine alternator wires will plug right in.
And Yamiya(OEM) parts Japan, has the short pigtail from the engine to the wiring harness.
About $57.00 with shippping.

jadedjackal · « **Reply #21 on:** November 04, 2011, 04:58:49 AM »

I'd love to see some pics of harness replacement and re-wire. I want to tackle it on my 750 eventually as well. I just bought this 750 and I haven't owned an old Honda for over 18 years. I never did major rebuilds back then either but I know enough to get me in trouble.

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Author Topic: My 1978 CB750K Project (Read 2448 times)