Topic: Introducing my new to me 1977 CB750

[MiniDitka]

Hello lunatics, speed freaks, and gear heads.

I recently became enamored with the idea of getting a vintage bike to wrench and ride.  Unfortunately once an idea like that enters my head it becomes a virus and immediately takes control of my cerebellum.  After looking at ads on craigslist for a month I made what is likely an ill advised purchase that I am very excited about.

The bike cost $800 and has a title that matches the frame but not the motor.  Does not run but easily turns over.  This is actually my first bike but I have ridden before (not that I will be doing any riding anytime soon).

I plan to immediately get a battery and replace clutch, throttle, brake, speedo, and tach cables as well as a new front tire.  After that I do not know exactly what to address but plan to read up on here, but my guess would be hoses, fluids and filters.  I would really love some pointers as to how to proceed.  The overall goal is to get the bike running decently well and let her tell me what to address and eventually do some variation of a cafe build.

Without further ado, here are the pictures of what will probably be deemed a mistake (I am excited regardless).








































This site is an incredible resource and I look forward to sharing my progress and stealing your knowledge! 

-MD

[Cabilao]

welcome to the club. shure this is 77? look more like a mix of different bikes to me. just wait what our experts here say to this"Frankenbike". but oil and fuel tank and carbs are not 77. and my 77 frame looks also different. will follow this post to see what come up. good luck anyway.

[Don R]

She appears to be highly customized. Fear not, lots of years parts interchange and there is no accounting for the actions of a PO. (Previous Owner) A nice riding bike can be delivered from your investment. The search function on the left works and if you choose your words wisely it will turn up a gold mine of information. Be sure to read FAQ's and tips and tricks. An Excellent book is available written by our own resident expert Hondaman. You need to have patience and enjoy learning about these fine machines. The swingarm apperas to have lowering blocks of some sort. Hopefully they are removable, if you are inseam challenged you might consider leaving them although they will have some effect on handling.

[750K]

The swingarm isn't hacked up, it just has some sort of lowering blocks bolted on. It's not a 77 frame, 77-78k's have the seat hinges on the left side of the seat rails with the lock on the right. So the tank, seat, carbs, oil tank and side covers all make sense if it's a pre 77 750. What's the frame and motor vin #? I'm sure someone can figure out exact year from those #'s, frame and motor #'s are different unlike some bikes.

[Don R]

BTW, the engine number never matches. it would be a hand stamped replacement if it did.

[ekpent]

Welcome to the madness.  As 750K mentioned either post up the engine and frame numbers or use this popular chart to find out first exactly what you have for starters. Some bikes have a lot of mixing and matching going on over the years.  http://www.hondachopper.com/engine/engine_timeline/timeline.html

[Xnavylfr]

Nice find WITH TITLE! You might want to also join in at this site also!!

http://hondachopper.com/

The lowering blocks are usually removable unless these were HOMEMADE and welded in place.
 I don't want this taken as DIRESPECT to this site or anyone here but , I've found them to be NOT very happy with ANY modifications to a stock CB. This site has YEARS of experience on these bikes but they just don't like us cutting one up and building it a different way. Ratbikes,Bobbers, Cafes, or Choppers are a better fit over on HC.com because most of the guys/gals there have already modified a CB750. Some have changed as little as just adding some Chrome to others as much complete changes to where the only thing 750 about it is the engine!!!

Here is my most recent build and this is the 5th chopper I've built!!

Xnavylfr(CHUCK)

[Johnie]

Here is a pic of a new 1977 back in the day for comparison. Correct the tank and blinkers are not 77 among other things mentioned. Be sure the title matches the numbers on the bike.

[Xnavylfr]

Didn't the 77/78 have the trap door tank to get access to the cap???


Xnavylfr(CHUCK)

[Bankerdanny]

Definitely a mixture of years, but unless you are trying to build an original show bike who cares. A complete bike with a clean title that matches the frame is all you need to end up with a nice bike that can be registered and, when the time comes, easily sold on.

Nice find.

[MiniDitka]

Thanks for all the info.  I bought the bike expecting it to be a franken-bike of some variety.

Unfortunately I travel for work and I am stuck in Wilmington, DE this week, but will look into the VIN numbers and post the results here.

I will have to get a closer look at the lowering blocks to see if they can be removed easily with a wrench or will require a cutting wheel.

From where do most people order replacement parts online?  What about a battery or a tire?

Thanks again,
-MD

[MiniDitka]

She appears to be highly customized. Fear not, lots of years parts interchange and there is no accounting for the actions of a PO. (Previous Owner) A nice riding bike can be delivered from your investment. The search function on the left works and if you choose your words wisely it will turn up a gold mine of information. Be sure to read FAQ's and tips and tricks. An Excellent book is available written by our own resident expert Hondaman. You need to have patience and enjoy learning about these fine machines. The swingarm apperas to have lowering blocks of some sort. Hopefully they are removable, if you are inseam challenged you might consider leaving them although they will have some effect on handling.

I would love to support Hondaman and the forum, and the book might make a great suggestion to the SO for christmas.  I have used the google search here to try to find a live coupon code, but to no avail.  Is there a current one?

-MD

[Johnie]

Correct the 1977 & 1978 had the trap door over the gas cap. Regarding your VIN...in WI the bikes from that era were titled by the engine number. Other states titled the bike by the frame number on the steering head neck. Just wanted to mention that so you do not get to excited until you check all numbers to hopefully have a match.

[bollingball]

http://www.batterystuff.com/?gclid=CLKj0JnCj6gCFRFj7AodyVBuEA

http://www.motorcycle-superstore.com/0/0/Motorcycle-Tire-Finder/Tires.aspx?WT.ac=All_Tires_-_Footer_1_05.07.12_TFBanner
 Welcome Yep frankin bike and a good one.
Ken

[ekpent]

Just to address one of your concerns the lowering blocks for the shocks are a simple bolt on affair that will be very easy to remove so hold off on that cutting wheel,for now anyway. Heck there may be someone around here who may want to buy them from you 

[Xnavylfr]

I took a close look at the lowering blocks also,,, They are just bolt-ons, a bolt through where the lower shock eye would bolt and another (vertical) just behind the adjusters!!!.. Save the lowering blocks maybe some of us CHOPPER bums would want them!!
As for the VIN, as long as they match, you're good to go even just engine VIN. I had a KZ1000 that was registered by engine number. Of course all the EXPERTS told me that it CAN'T be done by engine# but I NEVER had a problem!! Mainly because back in the 60/70 when HARLEY was the target for theft, they didn't want the frame, they wanted the engine to put in a CHOPPER frame, so that is why the engine # was used for VIN especially in the north= Wisconsin, Michigan

Xnavylfr(CHUCK)

[MiniDitka]

According to the Serial number decoder on this site (sorry can't post external links, despite it being for a link here).

We are looking at a 1977 frame and a 1971 engine.

Perhaps I am decoding it wrong:

Frame Serial Number stamped on the neck:
CB750K-27017##

Number stamped on engine:
CB750E-10943##

-MD

[madmtnmotors]

You would then have a 77' neck welded to an earlier frame. Look at the connections between the steering neck and the frame to be sure it wasn't "cobbled' together. If done properly you should be fine, otherwise this is a bad location to make compromises. I would suggest comparing this part of the frame to another CB750 frame to see any potential deficiencies. There's a slim possibility that the numbers were "restamped" onto the older frame.

[MiniDitka]

You would then have a 77' neck welded to an earlier frame. Look at the connections between the steering neck and the frame to be sure it wasn't "cobbled' together. If done properly you should be fine, otherwise this is a bad location to make compromises. I would suggest comparing this part of the frame to another CB750 frame to see any potential deficiencies. There's a slim possibility that the numbers were "restamped" onto the older frame.

I'll take a closer look when I get home this weekend.  That would be bad news.  I assume the motivation of which would be to save the neck so that it is "titled."  Meaning the rest of the bike is unknown, but perhaps all 1971.

Thanks for the insight.

-MD

[madmtnmotors]

Yeah, as noted in some of the earlier posts, the seat hinges match the earlier frame (they switched sides in 77/78), the oil tank matches the earlier version (but the oil tank MAY mount to the newer frame, not sure), fuel tank matches the earlier model, along with the early engine model everything points to an early model. "Restamped" would be the least amount of modification whereas replacing the neck is more involved. If the work was done properly (either way) then you should be fine, just see if you can compare what you have to a known stock frame, maybe see if you can get a nearby member to ride theirs over for comparison.

[750K]

I have a bare 78 frame in my garage, I'll see if I can snap a pic and post it up for comparison. I wouldn't worry about it as long as you have a clean title in your name you'll be kosher, I'll see I there's anywhere a secondary vin is stamped. I know cars usually have multiple vins stamped on the body, not sure about the Cb750 though.

[brewsky]

The triangle section of the frame that serves as rear footpeg/muffler mount is not 77/78, but it has a 17" rear wheel?

[stereosilence]

Welcome! Where are you in Atlanta? I'm over near Decatur. I picked up a 550 a while back and have become consumed. Good luck!

[Stev-o]

....but it has a 17" rear wheel?

Looks like a HD 16" wheel, a very common mod back then.  Why you replacing the clutch if you haven't tested it?  May not be necessary.  I would start by getting a battery (Sears $50) clean the carbs and install. Then fire that Frankenbike up and see what it does. 

[Eydugstr]

MiniDitka - Congratulations on your new find - welcome to the madness!

As others have pointed out, the bike is definitely a frankenbike...The speedo/tach unit is from a '71, as is the seat latch.  The battery holder boxes on the '77's had three bolts holding them to the frame.  Yours is an older style, using four.  Also the front caliper is the older style caliper.  The carbs are the older style (71-76) too. 

But with this being said, don't panic...Think of it this way - It gives you the license to do whatever you want to the bike without worrying about keeping it "original".  A similar thing happened to me when I got mine (PO bolted a '77 front end, battery box, and electrical system onto a '72 frame).  You can still make a great looking ride with what you've got.