Sreter's '73 CB750 Cafe Project

Hello, my name is Lucas. I recently joined the forum as I was finally stepping into the cafe world after years of wanting a project. A little about myself and my background with motorcycles... I grew up around hot rods and antique Harley Davidsons and Indians (along with some other vintage European bikes) because my dad's passion has always been restoring these vintage vehicles. Ever since I could remember I had a wrench in my hand helping pops out with tearing down a 1930's Ford, '80s Porsche, or one of the '40s Harleys. The motorcycles prevailed and that's all he does now, collect antique HDs and Indians from the 1920's to the mid-late '60s and fully restoring them (check out my intro thread for some sweet pics of the collection). Other than that I grew up racing dirt bikes from the time i could touch the ground on my first bike, a Yamaha PW50, till i started college and ran out of time and money to race my KTM 300exc... I've become a huge VW and european automotive enthusiast in the past 5 or so years and have had my share of VW experience with my previous VW and current 2012 GTI. Aside from that, i graduated as a Mechanical Engineer last year and now work at Honda Manufacturing of Alabama as an ME

Anyways, I recently purchased a 1973 Honda CB750 for super cheap with plans on creating a Cafe Racer-inspired bike that I've been envisioning for some time... it was in really rough shape when i picked her up last weekend and the motor isn't running too great (misfiring, backfiring, running lean) but it should all be fixable and i'm hoping/thinking it'll just need some carb adjusting/syncing and playing around with the timing/points. This is all a learning thing for me since its my first personal project without my dad and I'm really excited to get going and create something of my own.

Plans for the bike:
Get the motor running strong and reliable
Rewire the entire bike
Weld up a rear seat hoop
New seat pan with cowl and a leather seat
Tear down for powder coating and painting the tank, seat pan and other pieces
New rear suspension
New or rebuild front suspension
Clip-ons
Rearsets
New headlight and tail light
New or refinished wheels
New tires
and of course repolishing/reconditioning of every other part as needed

Thanks for checking out my build and stay tuned! ;D

This is the bike the day i picked it up



(the seat looks funky bc the rear section of the bike was chopped off (pretty bad hack job) so i just propped up the seat on there to make it look semi decent)

Re: Sreter's '72 CB750 Cafe Project

So last night I decided to sand down the frame to clean up surface rust from a terrible job of detabbing by the PO and gave it a little black rattle can job. I also stripped the tank from some random black and dark red paint job and repainted it metallic gunmetal. It crazy how much better the bike looks already just with a quick temporary spray can job... My main focus right now is getting the motor running correctly and rewire the bike so when I'm done with that, it will definitely get a real paint job and powdercoating...






^my buddy's CL200 (fellow DTT member i.holmes) I'm helping keep stored in my garage

Here's the before shot... you can kinda see the rust and you can see the hideous diamond plate seat pan that was made by the PO

Re: Sreter's '72 CB750 Cafe Project

That's one good looking CL there in the background...

Just kidding, can't wait to see what other huge changes we'll be able to make to this thing once the engine is running right

Re: Sreter's '72 CB750 Cafe Project

i.holmes said:

That's one good looking CL there in the background...

Just kidding, can't wait to see what other huge changes we'll be able to make to this thing once the engine is running right

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lol. yea dude I cant wait!

Re: Sreter's '72 CB750 Cafe Project

Pretty big stride taken today on the electrical system... just ordered a new Shorai battery, new wiring harness, 7" headlight and bracket from DCC, ignition switch, and a new Ricks Motorsport reg/rec... next week I'll order a new ignition coil and figure out what else needs to be upgraded electrically

Re: Sreter's '72 CB750 Cafe Project

So my wiring harness and Shorai battery were delivered this week and the rest of the parts will be delivered tomorrow right in time for me to be back from some business travel. Hoping to start doing some work with all the electrical upgrades tomorrow night and do some car syncing/tuning Saturday morning with hopes in finally taking a real ride around town. Updates and more pics coming soon!

so turns out I have a 1973... not a '72. and of course, '72s have specific harnesses for that year so i had to order a new, correct, harness. on the bright side, the carbs are all cleaned up and the existing mess of wiring is all pulled out and laid out ready for the new one to be swapped in

went ahead and ordered some more stuff today... ignition switch bracket, drive chain adjuster set, fuse box assembly, and some Uni air filters.

Next to order is a Legendary Motorcycles Fiberglass "Brass" Cafe Racer Seat Pan with the brown cross stitched leather seat, the Legendary Motorcycles mounting kit, LowBrow mocha grips, Progressive front fork springs, and a rear suspension set (haven't decided which ones specifically... cant decide between Hagon or Progressive series 12 and need to measure it all out to figure out what size to get).

felt good to make some progress on the bike last night. Using a dremel i cut off the factory headlight ears (I know they can be properly taken off but seeing as I wasn't planning on reusing them again and they were in bad shape, the fastest and easiest solution was just cutting them off). Underneath was a ton of nasty corrosion so I used a wire wheel on my drill and removed as much as i could. After a sand on the corroded section of the forks and on the triple trees, I went ahead and painted it all black to match the rest of the frame... looks way cleaner now IMO!

PS excuse the messy garage... when my car AND the bikes are in there i keep it pretty clean and organized

With everything up front cleaned up, I went ahead and mounted the 7" headlight i got from Dime City Cycles. Love the way it looks but I'm gonna flip the brackets around today and see which way it looks better

New ignition switch and Uni pod filters came in the mail today so I went ahead and put those one

Also found a roll of thermal wrap laying around so I figured I'd put it to use and I actually like how it looks quite a bit

wiring harness came in yesterday so I went ahead and tackled that... I'm a mechanical engineer so engines, suspension, fabbing up stuff, designing stuff, etc. is what I'm good at... i know the very basics of electronics but man, looking at these diagrams and trying to figure out where everything goes from scratch was a real PIA! Nonetheless my buddy and I were able to start at the battery and little by little figure out where everything hooked up to and were finally able to put it all together with the exception of one plug.... for whatever reason, and I have no clue why, the PO decided to cut off the stator/alternator wiring harness 8-pin plug and replace it with a 6-pin, leaving 2 of the wires disconnected. So it took me a while to figure out where this random 6-pin sub harness went to till i decided to cut away the protective sheath and found the other 2 wires that were not visible before... anyways, the alternator sub harness is on order and as soon as I get that in, the bike should be ready to go!

so anxious to go home! Just got shipment update that my alternator sub harness is out for delivery today

also, I ordered a Hoop from SonicWorx and a "Thruxton" Seat pan and low profile seat from Dime City Cycles. Hoop will be here Thursday and the seat should be here before the weekend as well!

Right on man! Pumped to see how it turns out after the MechE treatment.

Tsfc said:

Right on man! Pumped to see how it turns out after the MechE treatment.

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haha yea man I'm super anxious to get this thing running right so i can focus on making it look good.

I dont know what it is yet but I just cant get this thing to start. It's got compression and spark and the new fuel lines show the gas being fed in there (although i have to lift the tank to get fuel to flow through bc I think my lines are too long and have too much upward movement for a gravity fed system)... I thinking it might be something internal with the carbs... I think i'm gonna have to rebuild the carbs with all new stuff and hopefully that does the trick... not really sure where else to turn to or to double/triple check :-\

you can easily flip the bail on an outer carb and carefully remove a float bowl to see if gas is present
you need spark,compression and a fuel air mix for the thing to run
why the large zip ties on the fuel line?
they are likely gonna cause a leak rather than seal properly

xb33bsa said:

you can easily flip the bail on an outer carb and carefully remove a float bowl to see if gas is present
you need spark,compression and a fuel air mix for the thing to run
why the large zip ties on the fuel line?
they are likely gonna cause a leak rather than seal properly

Click to expand...

I undid the drain screws and gas poured out so once i got the fuel to flow freely by lifting the tank, the bowls filled up no problem. I checked all 4 spark plugs and they're all creating spark. I'm thinking a clog somewhere in the carbs (I'll end up getting a rebuild kit for them). I'm not really sure. Its been a while since I worked on carbs (not since i was younger and worked on my KTMs with my dad) so i'm kinda relearning what to do and how to fix issues like this. The zip tie will be coming off. I'll be redoing the lines to get better flow and i'll be omitting those since I realized they're not necessary. Thank you for the input!

everything looks good so far. cant wait 'til you get it running.

I want the Works you have on your vdub