Topic: 1977 CB750k Rebuild or Cafe Racer.... (Lots of Pics)

[ethos42]

I just picked up a CB750 and stumbled across this site.

So far it looks like a pretty good resource for everything about these bikes and I really can't wait to get into it.

This is my second bike, I just finished rebuilding a 1986 Honda Rebel 450 (CMX450c) which was in pretty bad shape. I'm not a mechanic by any stretch of the imagination, but I am very persistent and resourceful.

I'm planning on using this to document the reconstruction of this bike. So to start with, here's some pic's of the bike in it's current condition:






It needs quite a bit of work as it sat outside for the past several years up in Payson, AZ. Not much rust, but lots and lots of grime/oxidation.

I hooked her up to the truck battery just to see what lights would come on, what would happen when I pushed the start button, etc.

Headlight works
Blinkers don't
Tail-light is broke, so didn't try that
Pushed the start button and the starter just spun.

I just helped a buddy with his 1983 Shadow 750 where the spring on his starter clutch broke, so I had become fairly familiar with the electric start on a bike. My first guess was that the starter clutch was shot... Boy was I right!

Starter Clutch on the flywheel


Flywheel with starter clutch removed


Bolts that had been sheared off


So I've got a new-to-me (read used) flywheel coming from E-bay. It looks to be in pretty decent condition, but we'll see when it gets here.

I noticed another guy on this site had a similar problem with his. Is this a common failure point? Should I upgrade the bolts on the new flywheel with better material?

While waiting for the flywheel there's not a whole lot I can do to try to start it up again (no money in the budget yet) So I'm working on some general shiny stuff

Tried a new method of cleaning old aluminum with sandpaper and Mothers Aluminum polish

Cam Tensioner before


Cam Tensioner After:



Alright, that's about it. Here's my short list of things I am going to work on and the order of their priority:
Starter Clutch
Battery
Oil Filter Bolt (Current one is COMPLETLY stripped, can't get it off)
Choke Cable
Clutch Cable
Carbs cleaned.
Air filters
Master Cylinder (peep hole is broken)
Brakes (front and rear)
Tires
Chain/sprockets
Fork Seals
Gaskets
Oil Seals
Break Light
Turn Signals
Ignition switch, Tank lock, Seat lock (w/ key)
Kill Switch
Side Covers
Paint Job
General cleaning to make it shiny.



Plan of Attack

• Get the engine to fire
• Get the engine to run
• Get it to shift into gear
• Get the brakes to work
• Fix all Electrical
• Fix suspension, tires, chain & sprocket

[ekim98]

Doesn't look to bad, and with what you've already listed to do you'll be good to go in no time, but don't hold your breath. Murphy's law will get into your plans some where during all your work. Keep posting pictures.

Don't know how you feel but for me I'd go cafe racer. Not any cheaper but restore parts can get expensive and are hard to find sometimes.

[UnCrash]

Welcome to the forums.

That bike looks a helluva lot better then if it sat outside here in Maine!!!!

Best of luck with your project and it looks like a great starter bike.

All the best-

[KB02]

You've got a great looking start there!! But, man, that seat has got to go...   

Welcome to the forums. Any questions you have, ask away. This lot is great about helping out.

Keep us updated!!

[S-Dog]

Those pipes look to be in GREAT shape.... Looks like a decent start.

[Short Round]

Welcome to the forum.  The bike you have there is a wonderful start for a project from what I can see.  Now when it comes to a matter of rebuilding it or turning it into a Cafe, its a matter of what you like and what you budget can afford.  I happen to enjoy the look of the Cafe bikes, but I also appretiate the restored bikes and the guys that spend a morgage on original parts, but I cant afford them.  Cafe's are fun because you get to use your imagination, fabricate little things here and there if you skills allow you to, and it really gives you an oportunity to put a little bit of you personality into the bike.  Im not saying that the OEM guys dont have personality because they do, they like to preserve these bikes (whick I will do down the road some day), where I see a blank canvas ready for sparks, appoxy, fiberglass, powdercoat, paint, blood, and sweat.  Its all a matter of what you like and are willing to do.  Hope everything goes well, keep us informed and keep the pictures coming.........Oh and please get that seat in the trash...............Chris

[ethos42]

Thanks guys 

I'm almost afraid to say how much I picked it up for.

Last night my "1 thing a day" was to get the oil filter off. The bolt is shot.

My first attempt to get it off I couldn't find a socket that would fit... Then I noticed that no socket was going to fit as the end has been pretty chewed up. I broke out the vice grips and some WD-40. It took a good bit of convincing, but she finally let it go



So I've got the oil drain plug out, and the oil filter. But I've read some people talk about an Oil Sump... What's that and how to do I get the oil out of it?

I'm waiting for my new flywheel/starter clutch so I figure I can go through and make sure all the old oil is gone before dumping in new.

[ethos42]

Just had another thought while browsing ebay...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=016&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=260175205548&rd=1

How much rubber is required to rebuild the carb?

On my 450 Rebel I needed the o-rings for the fuel stem and the bowl gaskets.

What's recommended to do a complete rebuild?

There are certain things I don't mind doing cheap, but others have to be done right the first time

[russouno]

You live here in Chandler, AZ ?
Thats where I am located...
 

[dusterdude]

welcome

[ethos42]

You live here in Chandler, AZ ?
Thats where I am located...
 

Yup

It's starting to get downright chilly on the rides into work these days.

That being said, time to head in

[russouno]

If you see this buzzing down the 101 or the 10  or anywhere around the Chandler/Tempe/Gilbert area, its me.

[rugger81]

Just had another thought while browsing ebay...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=016&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=260175205548&rd=1

How much rubber is required to rebuild the carb?

On my 450 Rebel I needed the o-rings for the fuel stem and the bowl gaskets.

What's recommended to do a complete rebuild?

There are certain things I don't mind doing cheap, but others have to be done right the first time

There's the o-ring gasket like you see in that ebay auction, an o-ring on the little drain screw of each carb, and o-rings on each of the little metal tubes that transfer gas between the carbs.  Thats all I can think of for the moment.

Also, if you want to do a full rebuild, then the only place I found rebuild kits for the 77 750k is here:
http://cgi.ebay.com/ebaymotors/HONDA-CB750-K7-CB750K7-KEYSTER-CARB-KITS-1977_W0QQcmdZViewItemQQcategoryZ35597QQihZ018QQitemZ280161541086QQrdZ1QQsspagenameZWD1V

I just rebuilt my carbs on my 77 750k in the spring with this kit, and it had basically everything you need to rebuild the carbs.  Just keep in mind that you need a kit specifically for a 77 750k, though a kit for a 78 750k may also work, I'm not sure.

[ethos42]

WOW!

That's actually a great price for the kit.

Just the gaskets alone were 20 bucks each for my rebel. Needles were another 10-15 each.

With 4 carbs to clean I was assuming around 150 or so for all the parts.

russouno

I'll Keep an eye out for ya.

If you see this:


Then you've found me

(for those that are curious.... here's what my ride used to look like

[ethos42]

This looks like a good deal as well:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=280161554261&ssPageName=STRK:MEWA:IT&ih=018

Have you used this set and can confirm that it fits?

[russouno]

I can confirm that this is a good set because it is the exact same set from the exact same vendor that I used on my bike. The ONLY thing I would recomend is this: The rubber 'o-rings that go inbetween the head and cylinders (4 of them I think about the size of a quarter?) for the oil passages, I would try finding some that are heat/oil proof and just a tad bit thicker but the same diameter.  After putting mine back together, the bike has the same problem it did before I replaced the o-rings.  (apparently this is a very very very common problem with these bikes....something about the rings arent quite thick enough?)
Anyways..its a good set at a good price.

[ethos42]

Today I picked up a few parts:

Battery
Spark Plugs
Oil Filter Bolt
Points
Condensers
Choke Cable
Clutch Lever
Point Cover

After installing all the parts, I took some time to shine up the oil filter housing.

So far I have just done the two outer parts. I hope to finish the middle tonight.

I'm basically sanding with 220 grit, then 500 grit, 1000 grit, 1500 grit, and finally 2000 grit. Then applying a few coats of Mothers polish, and a final coat of NeverDull.

I think I may go back over it for a few spots that still have scratches or pits.

[ethos42]

Not a lot of progress at the moment, just waiting for parts to come in.

In the meantime... Anyone know where I can get one of these?

[russouno]

are you planning on getting a different tank? If I remember correctly  the 77 and 78 both have a lid over the gas cap..... the gauge is cool though, now I want one.
Also, where have you been getting your parts? There is a really good bike yard in s. phx called Bob's Used Motorcycles, 16th st and Broadway abouts.   ever been there?

[andy750]

I have one still in the box!!! But I took it apart and cant get it back together again (not that Ive tried very hard).....I bought it from Ebay a few years back - its literally brand new...I took it apart as when I pulled the chain attached to the guage it didnt record anything on the dial so I unscrewed the back and thats how it still is.....anyway Im not using it (yet) so if you want it let me know....

EDIT - Let me just check at home tonite that it really is all there......

cheers
Andy

[ethos42]

russouno
I'm a frequent flyer over at Bobs

They have great prices, but I found a good flywheel/starter clutch for 5 bucks on ebay. Sometimes, Bob just can't compete.

andy750
You would be my hero if you were willing to part with that. The gauge is totally cool! Let me know if you still have it!


As for modifying the tank, I think I'm going to have to in order to do the Cafe Racer style. I was torn at first between stock and cafe, but I think the more I look at the bike and pic's of others cafe's the more I want to build my own

[ethos42]

russouno

I think I saw your bike up at Bob's the other day actually... Super clean bike, the pictures just don't do it justice how nice it looked.

[ethos42]

This looks like a good deal as well:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=280161554261&ssPageName=STRK:MEWA:IT&ih=018

Have you used this set and can confirm that it fits?

Just wanted to add a comment about these guys. They are REALLY quick shippers. I'm still waiting on other parts I ordered weeks ago... Gasket set came in 3 days after payment. Talk about service!

I can't wait to order my carb set from them.

[ethos42]

I just got my flywheel and starter clutch in and it looks like it's going to work great.

I'm at a cross roads though...

Should I put the bike back together and start it up once, knowing it has a ton of work to go....

OR

Start tearing the thing apart and rebuild the engine. I bought the gasket set and I was planning on replacing all the seals. But, if I tear the engine down, it's going to be awhlie before I get to hear it fire up for the first time.

I already know that even if I get it to fire up right now, I won't be able to drive it. The brakes are shot, the tires are shot, the forks are leaking, etc.

[russouno]

AHHH!! I was photographed at Bob's !
lol.. nice