Author Topic: 78 CB750F Cafe Rebuild  (Read 3449 times)

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Offline DANQ725

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78 CB750F Cafe Rebuild
« on: October 09, 2013, 05:17:14 PM »
I have just recently bought a 1978 CB750F that is pretty beat up and dirty for $400. I am by no means a mechanic and really have no real background with motorcycle restoration. Over the next few months I am going to be doing all the work to this bike by myself. I will be teaching myself everything and figured I would document the whole process for all to see. If anybody that is following this build has any tips/tricks or any sort of insight they want to throw out there, go for it. I may even have some questions for the people that find themselves checking back in this post.

Progress thus far:
« Last Edit: October 12, 2013, 10:38:43 PM by DANQ725 »

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #1 on: October 09, 2013, 05:35:31 PM »
Day One

Apparently taking photos with the phone is is turning the image sideways, so I will be taking the rest with my camera. Sorry everyone.
« Last Edit: October 09, 2013, 05:37:18 PM by DANQ725 »

Offline SOHC4 Cafe Racer Fan

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Re: 78 CB750F Cafe Rebuild
« Reply #2 on: October 09, 2013, 06:06:31 PM »
WELCOME TO THE FORUM! 

Are you doing a restoration, resto-mod, cafe, brat, bobber?  That tank looks a little rough.  Are you going to stick with it (repair) or go with something else?

There is much knowledge accessible on the forum, especially by way of the search window in the upper left corner.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #3 on: October 09, 2013, 07:53:11 PM »
Thank you for the welcome.

This will be a cafe as the final product. I am keeping the tank. It will be some work but I have confidence it can be looking like new. It surprisingly only has one dent. The picture didn't do much justice for it.

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #4 on: October 12, 2013, 09:11:41 PM »
Update 2:
I spent a few hours the past couple of days cleaning. The frame is completely clean along with the fork. I disassembled the fork and drained the oil. Apparently the oil hasn't been changed in forever because it was dark black and and thick at the bottom. Thats really all the progress recently. I am a 21 year old full time student so progress will be slow.

Here is the picture for the day. I forgot to do a before picture unfortunately. I will try to remember next time.
8 hours of work total so far.

Offline brandEn

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Re: 78 CB750F Cafe Rebuild
« Reply #5 on: October 12, 2013, 09:15:07 PM »
Sweet, another F3 getting some love.

Where in NorCal you from?

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #6 on: October 12, 2013, 09:22:08 PM »
I'm up in Chico. That's also where i'm going to college (Chico State).

Offline brandEn

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Re: 78 CB750F Cafe Rebuild
« Reply #7 on: October 12, 2013, 09:43:17 PM »
Awesome. I used to live there. Go there once a year to drink pale ale and see my brother ! Love Sierra Nevada and the taco trucks. 

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #8 on: October 12, 2013, 10:06:39 PM »
You, hands down, just named off the two best things about this town.

Offline SOHC4 Cafe Racer Fan

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Re: 78 CB750F Cafe Rebuild
« Reply #9 on: October 13, 2013, 12:04:05 AM »
I bet that fork oil smelled special.  I remember the first time draining 40 year old fork oil and wondered how it could smell that bad.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #10 on: October 18, 2013, 05:18:12 PM »
Yes the fork oil smelled awful. It reminded me of the tannery I used to run by all the time.

Update 3:
So I have just been spending a while cleaning everything spotlessly (nothing worth pictures). I got around to the engine. I had to borrow a impact driver to get the bolts loose. I have a set of stainless steel bolt to replace them anyways. Also have a gasket kit on its way. I am pulling this thing apart mainly with the help of forums on here so I thank all of you for that. So far everything looks clean.


Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #11 on: October 18, 2013, 05:24:16 PM »
A couple more pictures.

Having trouble splitting this guy in the second picture. Does anybody have any tips/tricks on how to get those 6 rubber caps off the head. I dont want to ruin them and I need to get to the bolts underneath.
« Last Edit: October 20, 2013, 10:13:11 PM by DANQ725 »

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #12 on: October 20, 2013, 09:47:01 PM »
Update 4:

So the past few days I got a couple more hours of work done. My buddy Rick and I did some frame alterations getting it prepared for a custom cafe hoop. I'm going to the store to pick up some tube sometime this week. We luckily have a tube bender at our disposal.

To date I think I have put in something like 25 hours of work. Probably more.
« Last Edit: October 20, 2013, 09:54:29 PM by DANQ725 »

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #13 on: November 05, 2013, 12:08:16 AM »
Update 5

So since last update I haven't really made a whole lot of progress. I had a very busy week at school, kind of broke the brake caliper on my car and had to fix that, and ended up going camping on the weekend. But the tasks that have been completed were taping/sandblasting parts, rebuilt the master cylinder, and slowly stripping the paint off the frame. I also spent an hour or two just organizing and cleaning my work space. I have also been working on acquiring parts in preparation of the rebuild. I will include a picture of those too.

My pup has been very good at keeping me company in the garage.

Offline tweakin

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Re: 78 CB750F Cafe Rebuild
« Reply #14 on: November 05, 2013, 06:00:41 AM »
I'm up in Chico. That's also where i'm going to college (Chico State).
Sweet...  Another F build.  I also lived in Chico for a bit a few years ago.  Really miss the MTB/road cycling and the beer.

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #15 on: November 05, 2013, 08:41:02 AM »
Unfortunately the biking season is coming to an end with the rain and cold rolling in. But beer season never stops.

Offline cheftuskey121

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Re: 78 CB750F Cafe Rebuild
« Reply #16 on: November 05, 2013, 09:44:38 AM »
Will be following closely :)

Offline CB750R

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Re: 78 CB750F Cafe Rebuild
« Reply #17 on: November 05, 2013, 10:08:39 AM »
Hey glad to see anger F get resurrected! I'm currently in the midst of refreshing mine. Will offer my 2cents when I can. Looks like you've gone ahead and cleaned up some bracets and such on e frame eh? You going to do a rear frame hoop? 


Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #18 on: November 05, 2013, 10:17:24 AM »
Yes sir we cut all the excess tabs off. And yes I will be putting a hoop on there as well. In fact I am going to pick up some tube today for the hoop. I am custom building my own oil tank and electrical housing to go under the seat and out of the triangle.

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #19 on: December 17, 2013, 03:27:38 PM »
Update 6

So it has been a while, but there is a little progress to note. During Thanksgiving break I had the opportunity to bend my rear "hoop" and weld it onto the frame. I then spent some time with my air tools grinding down the excess weld and cleaning a majority of the frame. I also did some more sand blasting and painting. I got parts of the engine painted and front forks. I also went out and bought another CB. I got a 76 CB125S for a sweet deal and spent a couple days cleaning it up and getting it ready to run. It wasn't starting up so I had to rebuild the carb and it started right up (there may be an issue with the electrical though because the lights fade very quickly and even stop working). Finals are this week, so that means I will have a lot of time to work on the motorcycles here soon.

I'm thinking I have put somewhere near 40-50 hours into the 750.
« Last Edit: December 18, 2013, 06:15:07 PM by DANQ725 »

Offline DANQ725

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Re: 78 CB750F Cafe Rebuild
« Reply #20 on: December 17, 2013, 03:29:10 PM »
The frame as of now.