Topic: Honda CB750 - a mash up of parts

[kyle750]

Just listed for sale on my local Thailand facebook group. Seller has a clear title and the bike is currently registered.  Not really interested in buying as it looks like a mixup of mismatched parts but curious what other SOHC forum members see and how you would evaluate this bike?

K0 tank and side covers
Engine painted black  - similar in style to the early Kawasaki K1 engine
Wrong seat - looks too small maybe from another CB model
Fenders painted black
Front forks painted black
No speedo cable
Modified disc brake system to the rear wheel?
Rust on the rear wheel rim
Exhaust with lot of dents - header pipes look decent
Later model turn signals
Gas cap and petcock don't look right to my eye

[kyle750]

I just read that the Honda CB750 K7 (1977-1978) Japanese Domestic Market had a rare rear disc brake. The most significant difference is the use of an F2-style swing arm and a rear disc brake, which was unique to the JDM K7 models, whereas other markets had a rear drum brake.

http://forums.sohc4.net/index.php?topic=142307.0

[kyle750]

Seller only supplied 1 photo.  Here is the same photo zoomed in

[pickleknuckles]

It's far from original...but I don't hate it.

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[kyle750]

It's far from original...but I don't hate it.

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Agreed.  I'm quickly warming up to it. But just because something might be rare does not mean it is worthwhile.

Originally I completely had written of the bike as cobbled together junk but have since started a dialog with the owner. IMO it's still a mash up of parts     First question to the owner - what year is the bike on the title?

[MauiK3]

Engine and frame number? That may tell you if the engine/frame were kept together or if it's an assembly of parts from other bikes.

[kyle750]

Engine and frame number? That may tell you if the engine/frame were kept together or if it's an assembly of parts from other bikes.

Thanks mate.  Yes a better check. I will ask the seller tomorrow? 

[Stev-o]

What is the asking price?   

A lot of us have had a bike with a "mash up of parts"!  Use what ya got...

[kyle750]

Older photos of the bike from the seller's FB profile

[BenelliSEI]

My cb750K3 has a lot of parts from other years.
Nothing wrong with a good mash up.

[pickleknuckles]

Agreed.  I'm quickly warming up to it. But just because something might be rare does not mean it is worthwhile.

100%

Originally I completely had written of the bike as cobbled together junk

I actually thought about doing a similar rear disc setup on my K4 that already has a K7 fork (taller lowers) w K4 tins and gaiters, and an F1 Tarozzi brace. ...but then I'd really just have a later model bike w/a '74 title. Lol.

First question to the owner - what year is the bike on the title?

Ha! Hopefully whatever year is on the frame.


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[kyle750]

Still waiting to hear back from the owner.  Here are the only 2 photos of the CB750 JDM K7 that I could find

Strange algorithm coincidence as the 1st photo showed up in my FB feed this morning

Why does the JDM model have less HP and higher RPMs??

[kyle750]

More photos of the CB750 sent by the owner.  Still waiting to see the title with frame and engine number but according to the seller all the numbers match the title. Having a valid title, tag, and registration on a 50 year old bike  is a big deal in Thailand and once inspected can be easily transferred to a new owner with no hassles.   The tag with 750 is very cool 

It is my understanding that Thailand no longer allows the importation of secondhand bikes into the country so  bringing in a vintage bike is now impossible. Before it was possible with outrageous 100 -200% import duties and VAT taxes in addition to strict and expensive emissions testing.

Late Edit:  The tail light is installed upside down 

[kyle750]

Surprise  . . .  Surprise 

Frame  CB750F - 1022110
Engine CB750E - 2531881

[rotortiller]

I like it, I like it a lot. Very cool looking  assembly of Honda components.

[kyle750]

Please look closely at the exhaust pipes.  Both the upper left and right pipes look like original K pipes but the lower left and right look smaller (perhaps off another CB model?)

[andy750]

That def is in an interesting bike with a collection of CB750 parts from across the years - recovered K1 seat, 78 instrument panel and indicators, 77/78 rear disk brake, airbox looks 77/78, gas tank has petcock on left side so later than 73?, love the black fender and rims very different. Wonder how it runs with those different pipes.

[newday777]

That def is in an interesting bike with a collection of CB750 parts from across the years - recovered K1 seat, 78 instrument panel and indicators, 77/78 rear disk brake, airbox looks 77/78, gas tank has petcock on left side so later than 73?, love the black fender and rims very different. Wonder how it runs with those different pipes.

75 K5 was change of petcock location to the left side.

[MauiK3]

the numbers point to a 75 F?

[kyle750]

The exhaust on the CB750 reminds me of this Suzuki exhaust with smaller bottom pipes?

https://www.facebook.com/reel/895554296259132

[grcamna2]

the numbers point to a 75 F?

I imagine it must be registered as that?

[kyle750]

short video from the seller

https://youtube.com/shorts/vwebyacybc0

[jlh3rd]

I just read that the Honda CB750 K7 (1977-1978) Japanese Domestic Market had a rare rear disc brake. The most significant difference is the use of an F2-style swing arm and a rear disc brake, which was unique to the JDM K7 models, whereas other markets had a rear drum brake.

http://forums.sohc4.net/index.php?topic=142307.0

I don't know about other markets, but the 1975 U.S. 750 F came with a rear disk.

that bike you posted, if it was a US. model, would be a '75 F frame with a '76 F motor.
In '77 , US., the engine fins were painted black.
no idea about JDM's.

that motor sounds pretty bad to me, but I'm not a 750 guy....hondaman is.
However, if a 550 motor sounded like that, and being the mix match bike it is, unless it's really cheap, I'd walk.

[kyle750]

that motor sounds pretty bad to me

Agreed.  Engine sounds bad.  Seller has been very helpful but because this bike is a mash up of parts I believe it is very important to visually inspect all the different components in person to see how the bike was assembled and if everything was installed correctly.  I have my doubts.     

[grcamna2]

Could that be chain slap in the motor ?

[jlh3rd]

I know that un-synched carbs on our 4's can make a motor sound like it's coming apart. Couple that with cam chain adjustment issues, valve adjustments, etc., and our motors sound like crap. Fix those issues and the motor sounds great.
That bike ...well....have fun. In addition to stuff already mentioned, I think they took a '77 head and put it on the '76 case. That's fine, it should work, but there's lots of other stuff going on. Is it a U.S. model ?