Topic: 1977 CB850 Cafe, Complete, Updated pics!

[BrianAdair]

First off, Hello to everyone!
My name is Brian, and I recently bought a 1977 CB750 basket case.... well kinda, the guy I bought it from started tearing it down about 3 years ago he said, and it's just been sitting in his shop. He didn't do anything to the engine other that take the carbs off, but he did take all the cosmetics off of the bike, I have or should have all the parts and bolts he had them in cans and boxes. He said he bought it in '79 and it shows 28k miles on the odometer, engine seems to be in good shape, haven't done a compression check yet or anything, but it does turn over and no signs of major issues.

This is the shape it was in when I picked it up this past weekend.


I have taken it down a little more, still have to remove the swing arm, forks, and engine.

I talked to a guy that owns a Honda grave yard aka (salvage yard) he also builds bikes, services, and is a parts dealer, in my area. I was telling him the  style i was wanting to go for, and he said to cut the frame where I can remove the valve cover while the engine is in the bike for future purposes, he said it doesn't weaken the frame, he raced CB's for 20 years and done his bikes this way. Have any of you heard of this or done it?
I'm just trying to get more opinions before I go chopping and screw something up, I am a welder fabricator by trade so that part doesn't concern me. I'm just worried about the structural integrity of the frame after removing the 2 smaller tubes under the backbone from the down tubes back to where the tank meets the seat.

Also from what he said and what I have read about the 77 carbs with the accelerator pumps and all, I am looking for a set of older carbs, I don't care to deal with those.

I will be getting rid of pretty much a lot of the stock cosmetic parts also, I was shocked that the original seat was in great shape. The guy i bought this bike from must have kept it inside.

I'm thinking of maybe finding a 73-75 gas tank also..... I don't really like the shape of the 77.

I will post more pics later.
Thanks for any and all help, or input!
Brian

[MasterChief750]

you could use the gordon frame kit. hednut makes them makes it so you can remove the section of frame over the head. i have heard from some old time 750 buffs around here that the frame cutting doesnt weaken anything but then why did honda put it there.

[BrianAdair]

Thanks man

That was my thoughts also, it was built that way for a reason.....

[BrianAdair]

Like I said I am wanting to replace the '77 carbs with something else.......... can't seem to find any Mikuni 29mm smooth bores...

I found a set of '76 cb750F carbs, will they fit since they are off of an F model and I have the K?

I read some where there wasn't much difference between the K and F in the earlier F models, just duel disk brakes up front, rear disk, and cosmetics.... just want to make sure before I buy them

I know I may have to change the manifold boots, or will I?

Thanks for any input

[Kerr]

Also from what he said and what I have read about the 77 carbs with the accelerator pumps and all, I am looking for a set of older carbs, I don't care to deal with those.

Did you read about this on this site?  I would like to read about that as I am doing a '77 750 also.

Good luck on your build too, I think we are at the same place in our builds (the beginning!).

[Coyote13]

I just picked up a '78 K about two months ago, will be paying very close attention to this build....hey, you're right out near Tyler! Howdy from Dallas

[BrianAdair]

Also from what he said and what I have read about the 77 carbs with the accelerator pumps and all, I am looking for a set of older carbs, I don't care to deal with those.

Did you read about this on this site?  I would like to read about that as I am doing a '77 750 also.

Good luck on your build too, I think we are at the same place in our builds (the beginning!).

I did find some info on here about the '77 carbs, it was the first year for the accelerator pumps, and they just sound to much of a pain to get set right and sync them. I just bought a set of '73's off of Ebay for $100. Im waiting on them to come in, so I can inspect and clean them up. Also I have found on Wikipedia, that 69 -76 had 67hp, 77- 78 had 47hp, then in mid 78 or 79+ it went back to 67hp. I'm not sure but I think it was due to emission crap, and maybe these carbs, I have also heard that the compression was lower and the cam was different. It is still the SOHC engine though so I don't see how to much would be different.
Good luck to you too man!

[BrianAdair]

I just picked up a '78 K about two months ago, will be paying very close attention to this build....hey, you're right out near Tyler! Howdy from Dallas

Yea man, I'm not far off of I 20 outside Canton.

Good luck with your build man!
Mine will probably be slow, due to I work all the time, wife, 2 kids, and most of all, money don't grow in my back yard.......
I was just in Dallas yesterday, anyway keep a check here I will post as much as I can on progress and pics.
When we get them up and going we should meet up and ride!

[DannyBhoy]

Good morning fellows. My in the middle of a 78 cafe project, so if you don't mind me listening in occasionally i will be glad to post any info that I have been  offered.
As for the frame mods, why ?. Will you be removing the valve cover regularly? If anything the old girl could use some gussets here and there to strengthen her. We tend to put better rubber on them on then they were made for as well as suspensions mods to make them handle better and it puts added stress on the stock frame.
Not sure about the carbs, I was also looking for something better. I do know that it varies on what you use for a air cleaners ie. single's / stock air box, mod air box, etc.  Not to say that the stockers are poor but I would like to put a 836 kit in one of my motors. I will ask around and share what I find out.

Best of luck from 3 kids and a large back yard.

Cheers

[BrianAdair]

I took the frame out, and pressure washed, started cutting the back end, the seat hinges, and latch off until I used up my only cutting blade I had.... Have to get more this week.



Getting ready to sandblast and powder coat, or paint.

Polished up the sump cover.

Before......


After.....


I have to weld up the stator cover it has some road rash on it and leaks oil.


I think all I'm going to do to the engine is clean it up replace some gaskets, and bolts with SS ones, and paint.
Ride it for a while stock, then later on bore it over.
That is why I was wanting to cut the section out of the frame, so I could get to everything easier without pulling the engine out of the frame again.

[greasy j]

have you seen gordon's frame kit, now made by another member and being sold on the site? makes it way easier to get the engine in and out, and is very reasonably priced.

I had roadrash on a stator cover and fixed it to not leak with jbweld. doesn't look perfect but will work in a pinch.

[BrianAdair]

have you seen gordon's frame kit, now made by another member and being sold on the site? makes it way easier to get the engine in and out, and is very reasonably priced.

I had roadrash on a stator cover and fixed it to not leak with jbweld. doesn't look perfect but will work in a pinch.

Yea, I have seen it on here, may look into buying one, if I don't make one myself.....

Yea I'm not to fond of JB weld... lol
That's what the other guy had on it, and I want to polish it up so just going to fill it with weld and buff it down.

I was looking at your build thread last night Greasy J, pretty nice I was getting some info and tips from what you have been through.
Keep it up, and Good Luck!

[BrianAdair]

My '73 model carbs came in yesterday, I haven't had time to do much with them other than take the bowls off and take some pics.

They will need a thorough cleaning and rebuild!

Have a lot of gunk buildup

[RM81]

Subscribed.

[HedNut]

Great to see another older model! Can't wait to see this come together! Excellent stuff! Cheers!

[BrianAdair]

Thanks guy's!!!

I started cleaning the carbs up tonight, Soaked them in a bucket of carb cleaner, then disassembled, and soaked all the parts again. I think I may go over them again, I want to blow every port out with my air compressor but didn't have it tonight. Also I'm going to try and shine them up a bit.


2 down..... 2 to go...






Anyone know where I can get a jet kit for when I get my 4 2 1 exhaust?

[HedNut]

Z1 Enterprises is your best stop for main jets  "Keihin 99101-393 Type Round Main Jets" are what you want....Whatever number you're looking for...they sell them for $1.60 each.

http://www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=keihin

It doesn't look like you're running the PD (77-78) carbs...so the slow jets may be easy to get for them too!
The later carbs have press in's...and they suck for sourcing...

Cheers!

[BrianAdair]

Z1 Enterprises is your best stop for main jets  "Keihin 99101-393 Type Round Main Jets" are what you want....Whatever number you're looking for...they sell them for $1.60 each.

http://www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=keihin

It doesn't look like you're running the PD (77-78) carbs...so the slow jets may be easy to get for them too!
The later carbs have press in's...and they suck for sourcing...

Cheers!

Thanks for the info Hednut!!!
Oh, yea I bought a set of carbs off of ebay, they said they came off of a 1973 model, they are the 657A carbs. Waiting on my rebuild kits to come in.


I have been so busy working lately haven't had time to do much on the bike. I will post updates and pics ASAP.... Hope to work on it this coming weekend.

[gnarlycharlie4u]

subscribed!

Z1 Enterprises is your best stop for main jets  "Keihin 99101-393 Type Round Main Jets" are what you want....Whatever number you're looking for...they sell them for $1.60 each.

http://www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=keihin

It doesn't look like you're running the PD (77-78) carbs...so the slow jets may be easy to get for them too!
The later carbs have press in's...and they suck for sourcing...

Cheers!

...yea. tell me about it. yeeeesh!

[BrianAdair]

Ok, I finally was able to do a little work on the bike this weekend....

I found an older tank the style I wanted, traded my tank for this one, it was clean inside and appeared to be strait but looks are very deceiving....... 
Found that it had been repaired before when it was painted with the flamer purple...





So I stripped it all down, and started bono'ing it up...





Primed, but found some spots I still need to go over, just wanted to get something on the bare metal so it don't start to rust.




Polishing....... polishing........ polishing.....


This Harbor Freight POS lasted like 5 hours.... I seem to keep buying crap there cause they are cheap but I have had so much JUNK break from there that I think I am done with them for tools. Northern Tool isn't much better, and just twice as much as HF.


So I rigged this up..... and it works WAY better, has a start up capacitor, and is thermally protected so it shuts down when hot instead of roasting the armature....
 

Cut the turn signal tubes off the stock headlight ears.


Welded up the tubes where I cut the rear of the frame.


Sandblasted the triple tree's


That's about it, seems like it is going slow, compared to the way most of you guy's on here post your progress pics, but I'm doing as much as I can when I have time. Haven't had much time in a while.

Also there is a Honda CB graveyard about 20mins from me, and its not just a wrecking yard he has all kinds of new parts still in the boxes from the 70's.... and he has been very friendly and helpful, traded him a bunch of Harley parts I had that some one gave me for store credit to get stuff I need.

[Old75_ratafe]

Looking good man, how bad was that polishing job?  Noticed you said 5 hours was that five hours straight? lol

[BrianAdair]

Looking good man, how bad was that polishing job?  Noticed you said 5 hours was that five hours straight? lol

lol no not straight, I may have done like 2hrs at a time. It wasn't bad, I kinda like it...
I would do it until I got tired then go do something else, and come back to polishing later.
The three parts in the pics that are polished is probably around 10hrs total.

It goes faster if you wet sand the parts first, and they also have a varnish or clear on them so you have to strip that off, or you will be there forever..............................lol
I tend to be a little OCD so I will probably hit them on the buffer a few more times before they are back on the engine.

Thanks for the compliments man!

[Old75_ratafe]

Yea I am the same way I wasn't going to do anything on my bike then I accidently hit a spot.... Now I'm contemplating the whole engine lol.

[mrrch]

Polishing is a chore but strangely addicting. I kept finding small imperfections. I must have OCD

[Old75_ratafe]

Polishing is a chore but strangely addicting. I kept finding small imperfections. I must have OCD

I "accidentally" got some mothers polish on my controls... then the valve cover... then the master cyl... I did it by hand... and am contemplating going back with a wheel now.