Topic: 72 CB750 Budget Build

[niels.d]

Hey all, kinda new member, don't think I've ever actually posted anything here. First off, I'm a total newb, this is my first motorbike ever, and I don't have pretty much any real mechanical background.

Over the last couple of years I began to become interested in motorcycles, I always loved and obsessed over cars as well as BMX bikes. This past summer and early fall I began checking local classified ads to get an idea of how what sort of a project I could find in my area. There didn’t seem to be tons of old bikes for sale in New Brunswick, Canada, but occasionally I’d be tempted by something, like an early 80s GS750 – not the most desirable bike for a café- or brat- build but decent nonetheless. The desirable platforms seemed to be way too expensive for me. 

In early October (iirc) I stumbled onto an ad on Kijiji for 2 non-running CB750s, both ‘72s, about 45 minutes away. One was a hideous yellow 80s monstrosity that turned over but didn’t run, the other was pretty much stock put missing parts and had a ceased motor. So, a friend and I took a drive out and looked at them and spoke to the guy selling them. The previous owner was probably in his mid 50s and seemed to be pretty straight up and honest about the bikes. He said he had bought the yellow one a few years earlier from someone who claimed to have it running the previous year, but the mess of electronics and rats nests of cables made him (and me) think otherwise. The bike was hideously rebuilt in its former life, and one of the POs seemed to have rebuilt the engine or something since the block has been painted black at some point (now pealing heavily) and there are an assortment of hex bolts throughout the exterior of the engine. Hopefully I don’t find he or she did anything to terrible to the inside.



The Yellow bike in all her 80s sexy glory.

The guy I bought it from had said he always dreamed of restoring one of the old SOHC4 Hondas so he bought himself this one as a project. Wanting to restore it to original condition he bought the second ceased bike for a parts bike. Apparently he bought it in Ontario and had it shipped to NB without ever seeing it. Along with these two bikes as shown came a box with some extra parts: the carbs from the ceased bike, an aftermarket headlight, misc wiring and electronic bits from the ceased bike.




The parts bike, complete with bullet holes for extra speed/bad-assery.

So I ended up paying $700 for the both of them. Probably not an amazing deal, but considering what else was around here, and the fact that I have quite a thing for CB750s, I don’t think that I got too ripped off or anything… so long as I actually get one of them up and running! Obviously, I had my work cut out for me, I clearly have a lot of work ahead of me to make this bike anything close to road-worthy.

Since then I have torn them both apart and began to get ready for my rebuild. Stay tuned, will post an update of some more recent pictures and also share a bad luck story as well.

[Elan]

welcome, I think you got a decent deal. Theres a lot of knowledge here that can fill in any blanks in a rebuild. Im underway on my first rebuild now and this site is priceless.

[tango911]

Welcome and congrats on your finds.  I too am doing a budget build (low budget) and its also a 72 CB750.  I did the same thing you did and bought a complete bike and a parts bike.  If you need any help or have any questions that i can help with just let me know. Im about %75 done with my project.  I may even have a part that you need or vice versa. Keep the pics coming.

ill be watching the thread,
steve  aka tango911
18atango911@gmail.com

[noahspop]

Welcome aboard. That seems like a pretty good find. You should be able to piece together a decent bike. Some of the memberd might have what you need vice versa. This will keep the build cheap. Good luck.

[niels.d]

Thanks for the welcomes guys, I'm sure this website will be a great help, seems like a lot of knowledge and experience on here.

I have no access to a garage, so I gotta try to work around that. In the fall I began to strip both bikes down to just the engine in frame outside, and organized and stored all the parts in the corner of the basement of my duplex (bad move). Pleases excuse the crappy iPhone pics, I’ll probably be using a better camera from now on since my roommate just got a sick SLR and I got my dad a pretty decent digicam for Christmas so I’ll try to borrow something.








My growing stockpile of parts in the basement of my townhouse

Then, December comes around and instead of snow we get the craziest rainstorm in recorded history, and my basement floods. Well, that would be misleading, only the corner where I stored by parts floods… basically add 4 inches of water to that previous picture. All my bags of electronics got soaked through and through, as well as a #$%* load of other pieces. Looks like I’m going to pretty much have to restore every last part now and get a whole new wiring harness. When I discovered the water I was really disheartened about this whole project, but I’m hoping it won’t screw me too bad.

On a more positive note, instead of trying to rebuild my bike in the sketchy, flood prone basement of my home, my dad approached me and asked me if I wanted to work on my project in his basement. My parents recently bought a house just a couple blocks away, and after completing a bunch of renovations to their new old house, my old man and I cleaned out the work room in the basement and the two of us with the help of my two of my roommates carried both engines in the frames down into the basement. The narrow 90-year old stairs were a bit of a #$%*, but we managed to get them both in safely without crushing any of us.


My two frames/engines in their new home.


The workbench I’ll be rebuilding my engine on.

So I’m sure things will change and my plan will evolve, and while I don’t know about what I’m gonna do paint wise and looks wise, I’ve got a few ideas.

The Plan:
- Complete engine rebuild: new gaskets, seals, chains, stainless hex bolts, etc.
- Homemade wiring harness with everything deleted: no turn signals, might delete high-beam, kickstart only…
- Paint/polish/refurb everything.

First I’m gonna concentrate on the engine build, then the eletronics, because that seems to me like what I should prioritize.

[seanbarney41]

Your electrics and wiring harness may not be damaged as much as you think.  After all, they are designed to be out in the elements.  I would certainly clean all contacts and connections of any corrosion.  This is an important part of any rebuild anyway.

[Stev-o]

Welcome from Texas! Looks like you have a nice project, keep us updated.