Topic: Prototype CB750 Pictures

[Ted Nomura]

I think the CR750 engines had upper engine mounting.
I noticed the prototype CB750 tested by Cycle Guide in March 1969 issue had a valve cover with upper engine mount hole that was not bolted. I guess the Honda thought it was not necessary so it was eliminated on the production engine, along with the steering dampler.

On another subject, I added 8 more motorcycles to my collection since I started to reply on this post section 2 years ago. A 1963 Honda CA95, 1970 Honda SL100K0, 1971 Yamaha AT1, 1977 Kawasaki KZ750B and 1989 Honda PC800, plus 3 new Chinese made bikes and scooter. Chinese made bikes are reliable as long as you prep them right, including replacing with good grade oil immediately and go through the proper break-in period.

I'm still looking for a good 1971 Honda CB750K1 and/or 1972 Kawasaki S2 that I can buy cheaply in my area (Las Vegas). I bought the CA95 for only $200 from an ex-Nascar driver. It's almost mint and rust-free with an exception of one missing side-cover and a torn seat cover. Good deals are hard to find but not impossible.

[Ted Nomura]

I also believe that the original sohc 4-cylinder prototype in 1968 was a 650cc version (perhaps by doubling the new CB350 engine internal set-up for quick development period) with wet sump system and mounted on a modified CB450 frame but Mr. Honda himself wanted the 750cc so a new engine was designed because the 650cc was at its limit. The original engine design was kept and reintroduced as the CB500, then CB550 and finally the CB650.

Maybe in an alternative universe.

[rbmgf7]

i managed to acquire an original copy of chilton's honda fours repair and tune-up guide (circa 1972). it covers cb500, cb750, cb750 k1, and cb750 k2. it had a little history intro covering the honda fours.

[Ted Nomura]

I remember about 10 years ago seeing photos of a converted CBX to look like one of those classics, including the fairing and spoked wheels. It's too bad that Honda didn't make the 500cc or 750cc version of the CBX.

[tramp]

i heard the new 750 was made for overseas only

[Ted Nomura]

From the details you provided, it certainly sounds like the genuine prototype. I knew that the famous CB450 type tank black prototype also had the early CB450 type cut rear fenders (my 1968 CL450 have the same type fender, not the rounded type on later models). I didn't know about the CB450 centerstand but since the original prototype used many of the then-new CB450K1 parts, it would make sense. The early prototype like Bob Hansen's silver CB750 photo and 1968 Tokyo Motor Show blue CB750 also had a different type flip-up gas cap design. Only the very very early pre-production (actually a prototype using hand-made parts) CB750 had 4-digit numbers.

Only good photos can prove that you may have the most valuable CB750 not owned by Honda itself.

[Ted Nomura]

From the photos, that's definitely the pre-production CB750. Note the prototype model high Honda emblem on the tank (with K1 type tank strip) and disc brake. It looks like the same CB750 on the Honda ad, with the front disc brake with larger venting holes cut right into the disc itself. It seem to have the production master cylinder though, along with the gas cap and oil cap. If the original handmade parts were replaced along the way, it's going to be tough to restore them to the original condition. The prototype #2 had the front upward swinging seat (like my 1968 CL450) which were changed to side opening seat on the production model, like this one. The 4-digit number is a strange one though, I don't know any other CB750 stamped like that. Maybe it was an afterthought. Hey, I'll take that CB750, my life's been jinxed already ever since the CB750 started to dominate my life after I read that Japanese comics called "Ofukuro" (Mother) about a guy obsessed with his 1972 CB750K2.

That gold CB750 in England is also the same pre-production model but with regulation CB450K1 type taillight and the British preffered low-bars. That CB750 also need to be saved, even if they have to build the hand-made parts again.

It was easy to tell that the blue CB750 with the 1968 CB450 style tank shown first in this column was not the prototype. There were just too many things wrong with it, as I indicated earlier. The owner should bring it back to the original condition, with the standard tank and side badges, so it would be more historically accurate. That CB750 model is too valuable to be slapped with fake parts..

[Ted Nomura]

I hope that's not the case. I realize that retro bikes like ZR750/1000 Zephers and WS650s didn't sell well on the states but I think there's a strong market for Z1 and CB750 retros, especially for a large baby-boomer populations like me who likes the new Mustang, Challenger and Camero retro cars. I'm planning to buy the new Mustang myself, since my first car was the 1970 Mustang fastback with folding rear seats and a 351 Cleveland engine.

[Ted Nomura]

Hey, I just returned from a 3 week trip to Japan and there I picked up a February 1986 issue of Japan's Motorcyclist magazine from a used book store and it featured never seen before photos of the CB750 prototype. There was a color picture of the silver CB750 prototype #1 with a drum front brake but the tank striping was red on white rather than black on white that I believed before. The side cover's emblem was also red rather than black. There's also another front drum braked CB750 prototype photo in color which looks like the same frame but has different engine, exhaust, seat and slightly modified side cover. The upper triple crown is also chromed rather than black and the handlebar switches are more of the CB450 type rather than CA77 type on the silver prototype. The color is the same as the blue #2 prototype shown in the October 1968 Tokyo Motor Show, the tank looks like it came from the same bike, the seat looks the same too. There's also a beautiful color photo of the disk braked CB750 prototype shown in the original CB750 manual with the original side cover emblem.
There were other Motorcyclist issues that showed Z1 and H1 prototypes, along with the earlier Yamaha GL750 prototype with GL800 side cover emblem, black seat and four separate mufflers.
The earliest Z1 prototype as a 750cc mock-up in Santa Ana in 1969 shows 4 separate mufflers rather than 4 in 2 unit shown with H1 front end. The most interesting is the H1 prototype with thinned down W1 type tank and different instruments and side covers.
I'll put up the photos as soon as I figure this out. I'm still new at this.
I also found out that you can buy a Z1 type mufflers, tank and side covers for the 750 and 1100 Zephers now, at a price. Neat!  

[Ted Nomura]

Here's the first prototype in color. Note that the stripe is in red rather than black. Side reflector was added. CB500 type clutch housing and the point cover seem to have another Honda wing emblem.

[bikerbart]

Keep posting Ted, this is great stuff.

[andy750]

Keep posting Ted, this is great stuff.

+1! The red/white bike is really cool.

Ted when I went to visit Yamiyas shop in Nagoya I was told (I think as translation was difficult) that different Japanese cities had different colour tank strips e.g. different in Nagoya v Osaka v Tokyo - any truth in this that you know of?

I saw this in a Nagoya car showroom (and saw plenty of white CB750s in Nagoya with a distinctive tank stripe)







cheers
Andy

[Ted Nomura]

Very nice photos, Andy. The CB750 is a semi-custom, 1969-70 model with aftermarket cafe seat and other goodies like the chromed tach and speedo heads. The Honda emblem on the front forks looks like the one that came from the CB750 automatic. White tank was used only on the Police models. The Z1 looks stock, original 1972-73 model with a rare green and yellow tank. The Kawasaki logo on the front fork also came from a later model.

[Ted Nomura]

Not sure if I posted this before but here's a 1972 photo of two Z-1 prototypes thinly disguised as Honda CB750s being tested in America.

[Ted Nomura]

My 1969 CB750, photo taken about 10 years ago. Still needs restoring, many bits and pieces including returning the 16" back wheel to 18" and the instruments, which is a post K3 type. Got a set from the 1970 model. Seat is a K1 type. Front wheel is from CL450. Almost complete.

[Stev-o]

Not sure if I posted this before but here's a 1972 photo of two Z-1 prototypes thinly disguised as Honda CB750s being tested in America.

Interesting.   Was this for testing when they were riding them cross country?
BTW - I have a '75 Z1 B

[Ted Nomura]

No, this is just a used CB750 I bought as is in Vegas in 1991 for $800. Not sure if this was a test bike. The frame number is not even sandcast model but manufactured in 1969. Probably for just checking swapped parts. Came with a spare front disc brake wheel with original silver caliper. I bought another 1972 K2 model all stock including seats and pipes at the local Honda dealer at Boulder Hwy for $700 in 1991 too, three more fixer-uppers, two 1970 and one 1972 models for $200 each. Can't find deals like that anymore.

[Glenn Stauffer]

Hey Ted, do you have a copy of this book?  I know I'm asking a lot, but any chance you'd scan a copy that we could put online?

http://www.ebay.com/itm/1968-1969-1970-CB750-K0-PROTOTYPE-SANDCAST-RARE-CARTOON-COMIC-BOOK-MANUAL-/141188804706?pt=Motorcycles_Parts_Accessories&hash=item20df823062&vxp=mtr

[Ted Nomura]

Okay, I'll try when I find a good copy. Need to look for it.

[Ted Nomura]

Found another "K0" with 1968 CB450 tank in Japan but as a practice, Honda never put their wing logo on more than one place in each side of the bike.

[J-Rod10]

One of the prototypes (Blue one if I remember correctly) sold on eBay a while back for $145K.

The guy who sold it said one of them had been crushed at a scrap yard, one, nobody knows where it is or what happened to it, and the last, has been in boxes for 25+ years.