Topic: Could someone help me out with ID-ing this bike

[c15racer]

I've just been offered a CB750, I believe it to be a '77 K7.



I had a 500/4 not so long back and wish I never sold it, Having been offered a 750 local, it seems like an ideal chance to get another. Now the problem is I'm not very "up" on the different models of the 750. Is there a link to any info?

Also I’m in the UK but as this bike was a US one, I thought here would be best. I was told this model was re-introduced in America because the comstar wheel'd model wasn’t well liked?

The bike has a rear disc, but I think the wheel is a 17", I think this is maybe off a goldwing or another honda, so I’m pretty sure this is a DIY job?

The other thing is the pillion footpeg hangers, I've never seen them like this on any UK bike? Are they american fitment, it all looks TOO good, so perhaps these are factory fitment? Also the little black cover you can see is a inspection hole (with a rectangular plastic cover)



The engine number is a CB750E, is this correct?

[mcpuffett]

Hi it looks like a K7 , but the footrest hangers and rear disc brake set up look like F2, not sure about the 17" rear wheel though as F1'S & 2'S had 18" here in the uk, but as you say if it came from the states that would probably explain the smaller rear wheel  , cheers Mick.

[Geeto67]

Looks like you got a 77-78F model that someone converted to a K bike. Those chunky aluminum foot peg hangers will only fit the 77-78F frames. I am pretty sure your bike did not leave the honda factory in its current configuration.

The best way to tell is to tell us the engine and frame vin numbers (they don't match naturally so don't worry about that) and we can look them up, or you can look them up yourself on this site.

I am not aware of any SOHC that had a 17" rear spoked disc brake wheel. the 75-76 supersports had a rear spoked disc and the 77-78 K bikes had a 17" wheel so it is possible someone laced a 77-78K bike rim to a 75-76 hub but without details pics i can't tell. I do know GS750 rear disc wheels were also a popular back in the day swap.

Also, honda never discontinued the K bike so whoever told you they re-introduced this model is feeding you a line of bull.

If I had to guess as to the bikes history, someone probably had a k7-k8 they couldn't get paperwork on and chose to get a titled F frame and rebuild the bike on top of that. Since the F had rear disc it makes sense to convert. BTW, all 77-78Fs came with comstars from honda, no exceptions.

[Ace]

CB750E is the start of the engine number and indicates that it is a 750/4.  What are the rest of the engine numbers and also the frame number.  Looks like the rear foot pegs and pillion are off a CB750 F2 with that bracket and the little rubber rectangle bit you mention, however the wheels are off a K series.  Looks like you have a bit of everything on it.  The engine and frame numbers along with some more pics from all over will help us out in seeing what you have.

Beat me to it.

[c15racer]

Thanks for the very quick info.

All these 750 models do seem to be confusing.

Geeto67, If you say those big alloy footrest hangers ONLY fit the F frame then thats what it must be? With earlier spoked wheels?
Would that make the bike a F2 "supersport", I guess that would lower the value of what its worth too?

I'll try and see the bike again tomorrow and get the engine and frame number, I guess  that will prove what it is.

What pictures do you require? Ill get one of the rear wheel for sure.

Is there any obvious differences between the K7 and the F2 that I can look for? The F2's seem to have painted (black) engines? Unless this one has been very well removed, I didnt notice any trace of black.

[754]

F frame has sidestand further back, right on the corner of the bend up, actually.

[c15racer]

754, The sidestand did look quite far back, Is the K sidestand further foreward? The 500 was at the front.

[754]

K should be ahead or partly ahead of lower rear motor(footpeg) mount.. F is behind it.

[tygrant]

looks like theres some oil there around the base of the head. might need a gasket

[Geeto67]

Thanks for the very quick info.


Geeto67, If you say those big alloy footrest hangers ONLY fit the F frame then thats what it must be? With earlier spoked wheels?
Would that make the bike a F2 "supersport", I guess that would lower the value of what its worth too?

the 77-78F frame is the only frame where those aluminum plates will bolt on. YOu could modify a K frame to take those hangers but it is a decent amoutn of work as you need to remove the welded tubular K passenger peg and exhaust mount. It is possible someone did this but the work would likely be obvious. Take a good look at the alloy plates and see how they are mounted.

All I said is the Frame could be a 77-78 f2. As I said before it is likely someone used a K7 donor bike for all the parts and an F frame to get paperwork. That the cb750E engine designation means it is a K motor, F bikes would have an FE at the end of cb750. For registration purposes the bike is whatever the vin on the frame is. For fixing it purposes you may have to resort to both the K and F sections of the manual. you are kind of off the reservation on this one as it being an identifiable honda model.

As far as value, I would not pay any collector prices for that bike simply because it is not stock and may be made up of a bunch of different bikes. Get us the numbers and we can tell you what you are dealing with for sure and go from there. 

[c15racer]

Thanks guys, I forgot my camera but I think I know what the bike is for sure now.

The engine is a '77 K7 (this is what its UK registered as, (not the frame?!))

The frame is a F model, it says so on the headstock, according to the database on this site its a "F0" model? CB750F-11008** So what is a F0? If only the F2 had this style of frame/footrest mountings.

The rest of the bike must be K7, with just a later frame for an unknown reason.

The rear tyre is a 130/90/17, Is this correct for a F1/F2? Or is it a spoked/disc set up off another big Honda?