1977 Honda CB750F2 Cafe Racer

[TwentyFiveCustoms]

Hello all,

I started a 77 CB750F build over the same of 2019 and have not finished so far. The bike is decently far into the process and I will post pictures when I figure out how to. I spent $650 on the bike and put somewhere around 200-300 hours and $2,500 over the summer getting done what I have done to the bike. Most of the things that have been done to the bike have been on the high side of the price range for work and parts over the duration of the project so I am hoping that sometime throughout the school year and early into next summer I’ll be able to scrape together the last $1,500ish and that I believe is required to finish the bike. Unless otherwise stated parts that need install have been purchased and all work not requiring specific machining has and will be done by me as I do have access to a surplus of both motorcycle mechanic and construction tools.

Modifications/breakdown/work that I have done on the bike:
- Full frame strip down
- Tank modification from my stock CB750F tank using Bondo body filler to fill in and smooth over tank indents that are used to hold original tank badge in place
- Angled cafe racer seat hoop MIG welded onto slightly modified rear frame to accommodate the seat hoop
- Wheels cleaned and cup sprayed with Rust-Oleum satin black paint
- Engine block planed and cylinders honed
- Kibblewhite valves with APE Racing valve guides stamped in
- Clip ons with custom leather matching seat grips as well as bar-end mirrors with LED blinkers and new street racing style anodized silver and satin black shorty levers
- LED headlight with daytime running lights and blinkers painted white to color match tank
- Front fender cut down and cup sprayed w/ Rust-Oleum satin black paint
- Dug out broken spark plug in third cylinder
- Frame completely stripped of paint and cup-sprayed using Rust-Oleum satin black paint
- Custom black Honda logo decals for tank printed from sticker printing shop

To Do:

- Repaint tank (first attempt orange peeled after weeks of high grit wet sanding)
- Finish reassembling valves/cam
- Reinstall cylinder block/piston rings, valve block, and replace gaskets using full engine gasket kit
- Install stainless steel allen bolt engine kit
- Rebuild carbs using full carb rebuild kit w/ floats
- Replace cam chain with EK cam chain and genuine honda cam chain guide
- Rewire electrical harness
- Rebuild front forks
- Custom CNC machined triple tree out of billet aluminum
- Custom CBC machined front and removable rear peg sets
- Custom rear peg bracket
- Rebuild brakes
- Install small horn under tank
- Purchase and install CycleX Rapid Fire exhaust system for CB750
- Purchase and install K&N high flow pod filters
- Purchase properly sized jets and tune carbs
- Custom upholster seat and install LED strip taillight and blinkers
- New spark plugs
- Replace stock rear shocks (13in) with remote reservoir shocks (13 3/8in - 13 3/4in) for increased rear ride height
- Custom fab oil tank (most likely hide between frame pipes under seat along with electrical harness towards the front)
- Purchase and install battery delete (love the kickstart over button start)
- Possibly install oil cooler along front fork to decrease necessary oil tank size and exposure (could use help determining whether or not this is worth it/ a good idea at all as its just a thought)
- Purchase yellow “vintage look” spark plug wires and replace old ones
- Purchase either vintage style street tires or high performance street tires (gotta see how it looks more put together before the decision on tire style can be made)
- Full reassembly

I believe these are most of the things I have done and intend to do as I am able to. I am currently a second year mechanical engineering major at Clarkson University so I have brought the front forks, carbs, and tank with me to work on while I’m at school hopefully being able to use the paint shop and also machine shop to CNC the parts I will be designing. My goal for my project is not only to have a custom motorcycle built by hand by myself that has a perfect (to me) blend of retro and modern touches, but also be able to walk my hopeful future employers out to the parking lot to showcase my skills that have driven the project to be what it will become. As I am new to the forum (although I have used a good amount of information from it without creating an account) I figured I would throw my project up here as a first post. Hope y’all enjoy and absolutely feel free to drop tips/pointers as I went into this project with more knowledge than most 18-19 year olds but still have a lot to learn which has pretty much been the result of my entire project so far so tips/pointers would be greatly appreciated.

I also have an instagram account that I made to follow my progress although I was not great at updating it so it currently does not show where the project actually is but feel free to check it out and drop a follow or some likes @TwentyFiveCustoms

 

[dirtdigger]

Looking forward to seeing your pictures.

Couple things to consider:

There have been lot of conversations on here about the engine rebuilds on the 750 but I'll put couple of my must haves below anyway.

Leave the starter, All it adds is a small starter solenoid and a button...easily hidden. The kickstarter was never designed to be used continuously. It was only a backup for the electric start. Will it work, yes, but they do break especially under higher compression/bigger engines. Also the shaft only rides on the aluminum in the side cover, they do wear the hole out eventually. When you do break the kickstarter mechanism you have to split the case to repair. On top of that you WILL get tired of kicking it, especially first time you flood it or it doesnt start right away when cold or hot.

Oil cooler does not mean you can reduce oil tank capacity. You can reduce capacity to a 3 quart tank but would not recommend going smaller. Dont know what everyones obsession is with wanting to hide oil tanks, to me that is one of the appeals of the engine and makes them what they are. I like to make my tanks unique and part of the build but be sure they function properly, study how the stock one is designed inside, there is a purpose to the design of the tank.

Be sure to use new timing chain tensioner wheels as well as the guide. Use OEM Honda the aftermarket rubber wheels are junk. Also do the primary chains and tensioner when you have the cases split to do the cam chain.

Heavy duty cylinder studs are a must, dont question just do.

I would have suggested Cycle X steel valve guides in the head as it is an issue on the F heads but the APE's will work for a time but wont last as long. Also replace the top spring retainers, stock ones pull through and drops the valve.

 

[TwentyFiveCustoms]

Reply To: dirtdigger

Thank you for the thorough response I really appreciate it.

While I do understand the issue with the kickstarter being a pain in terms of not starting or flooding I had factored that into my decision and decided that I would make do if I do encounter those issues. In terms of the kickstarter breaking I was unaware of the likelihood of that occurring which brings up a question. Are you aware of any parts or ways to either replace or strengthen the stock kickstarter as it breaking would certainly put a damper on things.

With the oil cooler I had wondered if that would actually work for reduction of oil tank size and was throwing it out there to be told either yes that will work or no chance so I do appreciate the confirmation that that wouldn't work haha.

I did not think to replace the cam chain tensioner wheels so that will definitely be something I do as well. Same with the primary chains and tensioner.

I had also hoped to replace the cylinder studs as they were in relatively ugly condition, so now knowing that I will.

For the APE valve guides I had heard about the reaction with the bronze causing issues on the F in particular and almost did go with the CycleX guides instead, so I guess unfortunately I will just be making do.

Again, thank you and I appreciate the help and have now realized it would have been a good idea to begin posting about my project while purchasing parts so I will keep up with it as I continue my build haha

 

[dirtdigger]

The only part you can upgrade is the shaft and cycle x offers a cryogenic treated shaft. Other then that no other parts available. I dont even use the kickstart on any of my bikes anymore, even the drag bikes keep the electric start. Leave the kickstart on but use the electric. The starting system is hidden well on the 750 and its really easy to hide the solenoid and use a small lithium battery and a hidden button. You have the looks of the kickstart and the convenience of the electric. I really see no reason to delete the electric, weight savings is a moot point as the motor itself is relatively heavy. The shafts bend, twist and can break over time. The ratchet setups have been known to break and get stuck. All repairs require splitting the case.

The oil cooler is still a good idea, especially on air cooled engines. I look at things differently then some. I wont sacrifice engine longevity or function for looks. Oil is what lets the engine live why take a chance by reducing volume and over heat/working the oil. The parts for the engines are expensive enough the way it is.

Heavy studs are a necessity, I use them on stock builds. They are one of the weak spots on the stock motor...they stretch easy and lead to head gasket leaks.

 

[amc49]

Keep the electric starter like said, there is no comparison, electric can easily clear out a slightly flooded engine where kick will not follow through enough to do that until you are blue in the face. The engine is too big and the follow through on kick is not enough to really whack the motor up into the motion you need for a good quick ignite. I won't use the kick even on my 550, it's simply pathetic. Starter freaking rules and that's after riding DOHC for years, I predicted the no-kick engine design was flawed, what a mistake there! I never had a problem with it at all.