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Thread: 1970 & 71 cb750

  1. #1
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    Default 1970 & 71 cb750

    After many years in VLs I have ventured into the Honda CB 750s with a 70 and 71 and so back to the beginning of the curve.
    Could someone recommend an excellent book on restoring these year CB750s ?
    I am a detail freak so correct pieces for the right year including hardware and finishes is where I'm at.
    Thank-you

  2. #2
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    for the 1970 KO i recommend this site www.cb750sandcastonly.com i founded the website 2004. cb750sandcastonly is largely devoted to the sandcast cb750 series, but attention to detail on the so called "K0" is the same as all late vin sandcast 750's, except as the vins get higher on the later production K0's, there are difference, howbeit minor and subtle, so it depends on what vin range your 1970 is. and cb750sandcastonly includes "K0" owners to the "club." the "term "K0" is for fact a misnomer. from around sandcast Evin 3950 to Evin 7414, the bikes were standardized, the only differences were the 3 varying types of hex head bolt configurations. the "K0" series began production Sept.69 until June 1970, frome Evin 7415 to Evin 44649, the significant difference beginning Evin 7415 was die cast crankcases, not sandcast, which in it's self, the term "sandcast" is equally a misnomer. exception to cases, about the only difference between early and late "K0" vins are the larger the vin, the fewer earlier type bolt heads were seen, but even that can be a mixed bag. Honda was under tremendous pressure to produce units. Honda went from the idea of a production 4 cylinder in December of 1967 to producing the 1st production unit March 15, 1969. Research has found in the early months of producing the CB750, there seemed to be no consistency what the factory did to produce machines ready to go out the factory door. For example, between vin range 1-300 there is over 150 differences between this vin range and Evins after 3949.

    The K1 came out June 1970 with Evin 44650 and was produced until sometime very late 1971. The K1 is an improved and very different from the sandcast and "K0" units, more refined than the sandcast and "K0" units. The K1 was Honda's 1st major attempt to seriously meet market demand which was far greater than unit supply; hence the refinements. The very early vin K1's had a number of significant differences from the later production K1's, there is not a lot of documentation on these diffrences, only first hand experience will know these differences. i wold guess around Evin 50,000, all K1 units were the same until the end of the K1 production run.

    all of the books out there are generic for coffee table entertainment.

    for nitty gritty in depth major work, i recommend "my cb750 book - on putting them back on the road" by mark paris

    The rest of the books are great general references for getting started, but all are incomplete and all are inaccurate.

    3 Good books as follows, in order of the best book:

    "Original CB750" John Wyatt
    "Honda CB750" Mark Haycock
    "Honda CB750" Mick Duckworth

    Your best resources to get a much better idea of what ois correct and what is not correct are period print date Parts, Service and Owner's Manual and even those are fraught with inaccuracies, largely sketches *depicting* a part or pictures of pre-production units that are different than actual production units. Also helpful are Factory Service and Parts Bulletins. Nothing beats 1st hand observation of as many units as one can see or as you can find information shared on a forum.

    There is www.sohc4.net however it is not dedicated solely to restoration, the forum contains a wide mix of interest to things CB750 as well as a wide range of knowledge and the lack thereof. i have found in Japanese forums there can be a real lack of humility evident by what people post and there are a few guys who KNOW their CB750's.

    The sandcastonly website is a hardcore restoration site, so it will be helpful to your efforts to make your 1970 model correct, assuming your 1970 model falls within the "K0" vin range and is not actually a K1. One of the nuances of the K1, although it became available for retail sale to dealers in June 1970, it was called by the factory a 1971 model. It seems the factory wanted to get as far ahead of it's self in terms of producing a new model CB750 as it could.

    hope this is helpful. i can't seem to help not helping anyone serious about making a CB750 'right'. my expertise pretty much lies with sandcast CB750 models. incidentally, the factory, in those early times never acknowledged a "K0" model until around 1974. Many people mistakenly call a sandcast and a die cast 750 "K0." There DOES exist a very small number of actual so called "K0" units, but not even these were model designated "KO" by the factory. ALL CB750's from vin 1-44649, the factory simply designated them as model "CB750." the so called "K0" units were still in the same body trim as sandcast and die cast CB750's, BUT had the fulcrum operated carb actuation setup as seen on the K1 units forward until 1976, when the series was discontinued for an actual "K" model beginning 1977.

  3. #3
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    Nov 2013
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    Steve,
    Thank-you for taking the time to reply in great detail.
    I will look into all of this.
    Have you come across the site Honda 750 expert.com (69-78 Honda 750 buyers guide)?
    There is a claim within that KO was up to serial number 1044649, K1 thereafter?
    Just wondering if you had seen this resource and info and more importantly your thoughts on both?
    Thanks again

  4. #4
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    we've beat around the "ko" topic much on sandcastonly. i don't know about honda750expert.com, but the word "expert" concerns me right off the get go. oh well. what we've learned in sandcast circles and it applies in lesser detail to "ko" and early k1 is when we think we know, we find visual evidence supporting we don't know what we think we know. i only make assumptions and conclusions based on visual evidence seen and compared to actual parts, machines, vins and literature and than debate such on the sandcastonly forum. i will infere or postulate an idea to propse a theory based on evidence that supports the need to find more evidence to reach a conclusion. that conclusion can always be challenged for accuracy and validity.. my experience is there are quite a few "experts" who "know it all" based on what they think or read. what i know is i can be wrong and that's a pleasure because vi then learn something i did not know.

    to clarify on the term "K0"

    1. to date, the term "K0" has not been found in ANY factory literature until around 1974
    2. prior to the K1, the factory referred to ALL 750's as "CB750" - all vins inclusive of 1-44649
    3. there is no printed evidence the factory used as a "K" to designate a model until the K1
    4. there is a reason i put " " around the term "K0" is: Story has it AFTER vin 44649, there were approximately 200 machines built retaining the CB750 body parts, i.e., plastic gauges, Honda wing side cover badges on the 1-44649 type sidecovers and the duck tail seat. The ONLY Difference in these machines IS fulcrum actuated carburetors as seen on the K1 series, ALL pre-44650 vins had the 1into4 cable actuated carburetors. a few of these very early post-44649 units have been found, mostly over in UK and there is a substantiated reason for that as well.
    5. the term "K0" was not seen in Honda literature until around 1974 if i recall correctly. i would have to look at the print date on my little factory pocket spec's reference booklet that was published for mechanics use.
    6. i would have to look in my factory parts books to see when the term "K0" was first used therein. if my memory serves me, the 1st printing, February 1971 parts book refers to the K1 as a 1971 model and all prior models as CB750." i'd have to look in my various years parts books for the presence or absence of the "K0" nomenclature.

    Hope this helps clarify the origins of the "K0" terminology.

  5. #5
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    Bob, what are your E&F vins on both of your machines ? pm me if you like or email me at sandcast232 AT geemale DOT kom

  6. #6
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    Feb 2003
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    About 12 years ago I had a 1970 CB750 built in February of '70. If I recall correctly, the vin was around 22k and it had many early features like a ducktail seat, wrinkle tank, no numbers pipes, early handlebar switches, and early signal lenses... I'm absolutely not an expert and there were probably many other interesting features on the bike, which was to my knowledge nearly 100% original. It was in the original, somewhat faded, candy red paint and had just over 30k miles on it. I sold it to a collector in western Washington who said he was going to drain the fluids and put it in storage about 10 years ago. I thought it was very interesting, all the differences in the early production models such as the no numbers pipes showing up on a bike assembled in Feb of '70.. Kind of wish I'd have kept it now....
    Mike Carver
    AMCA #3349

  7. #7
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    Bob, enjoy this link. Yamiya has good stuff. i've dealt with them a lot since around 2003. http://www.yamiya750.com/

  8. #8
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    i just looked briefly and hondacb750expert.com a lot of info, much of it links to factory printed matter. from a restorer's standpoint i don't seem to be seeing much first hand observations of actual machines related to the author's first hand restoration experience. maybe i did not look long enough. i'm a little leary when someone brags the war this guy does. i think his name is John Grogan. if this is the same guy, then i've seen his stuff on ebay and i was not impressed, this guy on ebay sounds like this guy on expert.com. maybe not the same guy. not a site i would spend much time with. When it comes to the American contingency of Japanese restorers, i prefer to do my own research, then find the people who seem to know what they are talking about and compare my "notes" to theirs. if in fact your 1970 machine is a die cast 750 (pre K1) much of the info you will want to know is found on www.cb750sandcastonly.com i don't think you can go wrong using www.sohc4.net as a resource for your either of your bikes, there's just a lot more to wade through. there's a number of sandcast/die cast 750 guys in either web club who know their K1's. when i say die cast, i am referring to vins 7415-44649

  9. #9
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    Thank you Steve for all your input. I have sent you a private email. Thanks also Mike.
    Fascinating subject this.

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