My 1973 CB750

NMF

New Member
Fair warning: This thread will be very, very slow until the end of May when my XJ is "finished."

I finally decided to slowly start work on my other bike: this 1973 CB750.

D733E024-1FAB-419D-A3C4-CB2BEFE0B37E_zps6xqahnlt.jpg


I wasn't planning on touching it until my XJ was finished for the winter, (Still got a ways to go) but after working all winter on the XJ (and having this thing stare at me, dirty and untouched), and spending the past 12 hours of bike work on a fiberglass seat I decided I needed to at least do SOMETHING to this bike.

The backstory is that I bought it off of craigslist for $400 without a title (Before driving to pick it up I had the state police run the VIN to make sure it wasn't stolen. Once I pull it out of the basement and take it to the state police to get an MV-49 form (VIN Verification) I will then have it titled in Vermont, and transfer the title to PA.

The PO had bought it with the intentions of fixing it up, but when I arrived I could tell he was in pretty deep with other projects: Beautiful, massive old house that was just purchased, two Audi's and a VW that were heavily modified, a new wife, and a baby on the way.

So, for $400 I walked away with a complete bike, plus: Brand new Mac 4-1 exhaust system, CB400 Hawk engine in good shape, CB400 Hawk front forks, fenders, side covers, Comstar wheels, assorted parts, and most importantly: The CB400 Tank and Headlight that I have used on my XJ Build.

The bad so far(I'm sure there's more): Bike hasn't been started in two years, and the PO before the PO chopped up the harness to put on the drag bars you currently see. It will need rewired completely in the spring. It's dirty, and there's some surface rust on the wheels/frame, but nothing is pitted yet.

I decided that I would build a little paint booth in my basement and try to get this thing at least semi-aesthetically pleasing so I can enjoy looking at it a little more while I'm finishing up the XJ. This thing will not be receiving the full treatment like my XJ (at least not this summer. I want two bikes to have fun on, so this will be my "rat").

Therefore, all of the frame parts/triples and the wheels will simply be cleaned, degreased, and scotch-brited before painting with Rustoleum gloss black appliance paint, which I hear is very tough. I'll strip it down and do it right next winter when I'm bored and need a project.

Here's the "Booth"

76EBB515-9F41-49C3-A3F0-BA64A0358284_zpshkyxesvj.jpg


When I'm doing the painting in there I have a box fan that goes up against the filter you see there, which gives it negative pressure inside. I then place another box fan about 10 feet in front of that one, which pushed the air out of the basement door. I also wear a respirator with organic vapor protection.

Last night I lowered the front forks 1 inch by sliding them up the triples, took a wire brush to the rear shocks and then painted them with 3 coats of Appliance paint. Tonight I will finish prepping the wheels for paint.

I thought I was going to need to repaint, until I decided to see what a little clay bar and waxing might look like (below is a before/after of the side covers. Will need new emblems).

400F90E2-2F98-4521-9A72-EFF401963183_zpsrdg11y4t.jpg


A5E916E0-41F7-42D0-B018-DB4412BE1985_zpspduywf1j.jpg


Needless to say, I'm thrilled with the way it cleaned up. There are some imperfections, but that'll just add to the character.

Thanks for reading. Until next time!
 
Re: My 1983 CB750

Your thread title is a 1983, not 1973 . I was expecting a DOHC bike. No worries, looks like fun.
 
Re: My 1983 CB750

Cool bike, I'd probably throw a set of clubmans on it and ride it as is. Paint scheme is sweet. :D
 
Thanks canyoncarver. Thread title fixed. No DOHC for me, my other bike has me resenting anything with a step in the frame from here on out.

Desert KZ: I love the paint scheme too! Not a lot planned until the other bike is painted: clip ons, rearsets, new seat and getting it dialed in is all I have planned for this summer, but you know how that goes.
 
Haven't really done much to the bike. I decided to take a little break from my XJ to paint the wheels and rear shocks black with Rustoleum Appliance epoxy. It lays nicely and is supposed to be fairly durable. We shall see, it's temporary anyway.

6C2B8E1F-98AF-4A1A-88FE-80C1689C6725_zpsyfjt42u8.jpg




So I'm trying to install the Mac 4-1 exhaust (Well, just the headers, I'll be using some sort of different slip on than what it came with) that this thing came with and It is a real PITA to get it lined up properly and slid into the ports. Has anyone ever had this problem?

I'll have to take some pictures when I get home tonight so that I can explain further.

Also, the bike came without almost all of the levers/switches/throttle assembly on the handlebars, so I'm going to order all of that today. Can anyone here confirm that I'll need to purchase a push/pull assembly?

I do have the original front brake perch and MC, but the rear piece that bolts on to the back and holds it to the handlebars is missing. If anyone has a replacement I will gladly purchase it from them.

Thanks
 
I believe I may have an older mac exhaust, and it is a pain to install! I had to use shorter hardware (bolts, not studs) and different half moon compression spacers for it to fit up properly (see my build thread).

If you're wanting to do new hand controls check out the slimmer push/pull throttle housings. Emgo makes them and you can find them all over amazon or on DCC. There are nicer quality ones out there I'm sure but this seems to be decent if you're working on a realistic budget.
 
Haven't updated this since March! I guess it was a busy summer. Did lots of riding on the other bike and worked on both when I had time.

Lots of updates. But to answer/solve the problem from my last post, it turns out that the flanges on the Mac 4-1 dont mount flush to the head like I had originally thought. Some longer stainless bolts fixed that real quick. More on that later.

I did a full (though minimal) rewire using the VintageConnections.com connectors and ratchet. I'll probably do a new ignition and etc. this winter, but I wanted everything working as it should as-is.

I was hoping I'd get to ride it before I put it away in November, so I made a crude and quick seatpan.

3725E07E-6C7D-4134-8800-0DE39EEDE855_zpsj1n4qnkx.jpg


I then did most of the typical 3,000 mile maintenance: Cam chain tightening, valve adjustment, carb cleaning, oil/filter changes etc etc. Note that I have not synced the carbs yet. Went up on the jets, did carb gaskets, etc. Not everything, but enough to get it running, and running very well when it started up for the first time in many many years. Frankly, I just wanted to make sure the bike ran well before throwing a bunch of money into it. Bike started right away, but after a quick check of the valve tappets, I'm not getting enough oil to the head, probably due to clogged oil jets, so I'll pull the motor and replace all of the seals. Unfortunately it will not be ridden until next year, but everything looks promising, and the guys at SOHC4.com are a wealth of knowledge as well. Further, The engine would have been pulled regardless; the frame needs powdercoated.

Before I figured the oil issue out, I did a bunch of cosmetic stuff, which I know is not the right way to go, but my other bike is sorted out, and riding this before winter was wishful thinking. I finished the crude seat that will be done professionally in the spring (I'm going to make a thruxton type cowl for the brat seat), made a bracket for just the stock speedo, clip ons and horribly matching grips that will get changed, new cables, some stickers until I feel like buying emblems, CB400 hawk headlight, etc etc. Brakes/suspension, and other odds and ends will be taken care of this winter.

Heavily filtered instagram picture:

Don't mind the exhaust hanger. Using it for support until I figure out what slip on I'll use.

3F26B7F2-9A8E-46BC-BD3E-124C67905526.png_zpsi1sobog9.jpeg


Waiting on a joker machine oil pressure gauge, and just purchased this, which I couldnt find in *F

292F7968-D656-4158-B105-84BAA7A81354_zpsmmkqnryt.jpg


I still have so much to do this winter: cleaning, painting/powdering (but not the tank or sidecovers), replacing, upgrading, and so on, but I'm not going to stray too far from the lines it has, and will be focusing on getting everything running just like it should.

Cheers.
 
Back
Top Bottom