Honda CB750 Sandcast

Web Site Changes

Wayne · 116 · 42105

kp

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Wayne, the three tanks cover the wrinkle family. What may be a suggestion is to post a Yamiya tank so confusion does not occur. This is going to be a problem in years to come in that Yamiya parts will be passed of as original. In fact it has already happened in other parts of the world
Yabba Dabba KP


UK Pete

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With the yamiya wrinkle tanks, they must be good to be able to pass off as Honda, i have a copy candy ruby red tank non wrinkle, it is every bit as good as honda to my eyes ,
pete


CBman

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Gerard is right. Yamiya is still not 100% copy of Honda. But also as KP had said, some sellers are taking Yamiya parts as originals. This could make a risk at some purchaces, if you donīt see the bike personaly. I think that 80% of buyers are not able to recognized reproduction parts.


Wayne

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Thank you for your input and confirmation that I have the Honda wrinkle tank family covered. I'm a bit reluctant about adding Yamiya or any other aftermarket parts to the site for comparison sake. If it becomes a topic in the bulletin board that's one thing but to add them into the technical area of our site is another. Where do we stop? Tanks, switches, fasteners and so on?

I think it's best to keep the technical area of the site pure, with part numbers, vin break points and images of the original Honda parts as we know them. That's just my humble opinion.

Just on another note, it never ceases to amaze me how many running production changes were made on these machines and for what reasons. We know why the 19L tank was changed. They bring out the second design (mid run) with carb reliefs yet use an almost identical mounting pad footprint for the petcock. Then the long petcock comes along and they change the mounting pad footprint on the tank. Why not just use the longer petcock on the mid run tank? Why the need to make yet a 3rd stamping change? Maybe they found the longer petcock extended down too far and didn't look right on the mid run tank? Is there even a difference in the gap with one installed?
« Last Edit: January 14, 2015, 08:24:37 am by Wayne »
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Wayne

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Gerard
You didn't have to remove your post. I was only suggesting I didn't think it was best to put aftermarket parts here:
http://www.cb750sandcastonly.com/new/tech/frame_group_9.html

I'm fine with discussing and making comparisons on the bulletin board.  :)
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CBman

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Wayne: I would also like to see only original parts. Sometimes as you said these are enough.


Steve Swan

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At the bottom of this page on the current site it states:

"28" Cap with 6mm brass adjuster - These caps were recalled by honda due to sticking

http://cb750sandcastonly.com/support12.htm#Tanks

Should it not say:

"28" Cap with 5mm brass adjuster - These caps were recalled by honda due to sticking


yes, 5 mm adjuster


Steve Swan

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Thank you for your input and confirmation that I have the Honda wrinkle tank family covered. I'm a bit reluctant about adding Yamiya or any other aftermarket parts to the site for comparison sake. If it becomes a topic in the bulletin board that's one thing but to add them into the technical area of our site is another. Where do we stop? Tanks, switches, fasteners and so on?

I think it's best to keep the technical area of the site pure, with part numbers, vin break points and images of the original Honda parts as we know them. That's just my humble opinion.

Just on another note, it never ceases to amaze me how many running production changes were made on these machines and for what reasons. We know why the 19L tank was changed. They bring out the second design (mid run) with carb reliefs yet use an almost identical mounting pad footprint for the petcock. Then the long petcock comes along and they change the mounting pad footprint on the tank. Why not just use the longer petcock on the mid run tank? Why the need to make yet a 3rd stamping change? Maybe they found the longer petcock extended down too far and didn't look right on the mid run tank? Is there even a difference in the gap with one installed?

so after finishing this post, i realized it's a long one, so i ask those interested to please read through the whole darn thing.

i've never seen a yamiya body set.  from what i'm reading, sounds like they're excellent copies, but distinguishable from original.  unfortunately, I can't seem to find Gerard's post (it sounds like there is/was a post by Gerard that elicited Wayne's response.)

Certainly, if Yamiya parts have distinguishing characteristics from original parts, i do believe we need to know the differences from repro and original parts.  So, it would be nice to have a way to keep record of these differences.  Assuming there are differences between repro parts and original parts and no one knows it, then it makes all the later vins more liable to suspicion these machines are not built from original  parts.  The scenarios are numerous.  Deceitful sellers.   Pissed off purchasers.  Possible, but unlikely significant devaluation of certain vin range values.

anyway.... SOOC's duty is to record all the characteristics of these machines as they came from the factory.  It sounds like it's probably our duty to include reproduction parts.  However, i agree with Wayne, to keep the technical site "pure."  That is, reference to Honda oem parts only.  And Honda oem parts is another issue, because parts manufactured in 1969 do not always look like parts manufactured in 1977 or 1983 or 1997, etc, etc.  This creates another issue for the restorer as well as Wayne.  if the restorer wants to make his restoration exactly original, then does he install a Honda oem part made in 1977 or 1997 that does not look exactly like the 1969 manufacture part ?  How does Wayne obtain, much less identify differences in appearance between a 1969 built part and a 1977 built part ?

On the other hand.....  Gerard has a good point, even though unfortunately i can't seem to find what he wrote.  I assume Gerard's point is that because there are more and more repro parts available, we need to record and catalog these parts for comparison to Honda oem parts. Thinking out loud. Perhaps we need a category on the bulletin board where people can write in their findings, post pictures, differentiating Honda oem from repro parts.  Then, as the list grows, we could consider adding a new section in the website as to repro parts.  and perhaps also include differences between early production oem Honda parts and later production oem Honda parts.

As it stands, i appreciate and support Gerard's passion for preservation of correctness.  And i very much empathize with what Wayne is going through, taking this massive project on.  I know for a fact he has sat for hours and hours and hours and hours and hours in front of his computer monitor studying, organizing and reorganizing all the data he is faced with.  Really an overwhelming job, even for someone with Wayne's prowess at the keyboard.  That's only one reason why i turned over the website to someone who knows how to use a computer.  

What everyone enjoys reading in this forum is obvious.  Not the work of one enthusiast.  NOR IS THE CONTENTS OF THE WEBSITE THE WORK OF ONE ENTHUSIAST.  it's real easy to be an armchair team captain and say how things should be.  It's another thing to be sitting in Wayne's chair.  

So......  please, please, please, please.....  if sandcast 750's truly are your heartfelt passion, please, please, please contribute what you know.  as i've said numerous times in the past, this website is only as good as what is contributed.  I'm sure Wayne would have no problem making a forum category for people to write in their findings on repro parts.  That way, with a forum category, we could keep all our findings in one place.  and as the list grows, decide what may need to be done with the list.

Right now, Wayne's got a big enough job doing what he is doing.  I know, because i once sat in his chair.  So, give Wayne your support.  He needs more pictures of parts than are currently in the old website.  Write in and send pictures of what you have.  post pictures.  We're friends here.  We're fellow enthusiasts here.  Someday, with life's good grace, we may meet face to face, shake hands and clap each other on the back.


Steve Swan

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Wayne, as far as wondering why the differences, for example, in the gas tank bottom pans.....  no one has the answer.  we can only surmise.  i wold guess it has to do with what wasn't working.  both from both machine and production operations standpoints, for example, carb cables fouling tank, so the tank pan needed more room.  from production standpoint, maybe a stamping die did not release as cleanly so changes were made in the die.  and a third consideration was the guys who designed the tanks and the guys who designed the stamping dies.  and the communication that went on or didn't happen between design and manufacturing.    Lots we'll probably never know.  We restorers think about thngs that was no consideration for the factory.


Wayne

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Thank you everyone for your input and contribution thus far. I had a small setback, my new computer let me down and it took a day or so to get the problems resolved. Windows 8.1 is kind of like Windows ME. It should never have been released! ;)

Anyway, some of you have emailed some great pic's and information. Thank you! Here's and example of exactly the kind of stuff I'll be looking for as we work through the technical section and distinctions. Gerard has provided images with descriptions, but as well the untouched images so I can format, add the descriptions etc. as I see fit. Thank you Gerard. He has also provided some French Literature for the library.

Chris Noel has provided some good carb detail images and I have received pic's etc. from others as well.  :)

Again, thank you. You guys are the subject matter experts. I'm just trying to compile all this information in a format that makes sense, even to the laymen so everyone can learn from our site.


 
« Last Edit: January 17, 2015, 08:11:15 am by Wayne »
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hondasan

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More on gas tanks!!

Been out in the sheds today looking at my various wrinkle tanks, and believe there is a FOURTH factory variant as compared to the three identified above...

19 litre with short petcock

17 litre with short petcock, as shown above (came on #1120). Parts lists suggest a tank change at 1001938 for which there is also a service bulletin describing the change in height of the "pad" on which the petcock is mounted. On this first variant of the 17 litre tank, the "pad" is pretty well level with the bottom welded seam / edge of the tank (no trims fitted). It seems possible (to me) that the short petcock could also have been changed at the same time as the tank change. Need owner observations of bikes with VIN after 1120, up to at least 1938 or even later to support this.

17 litre with reduced height "pad" for petcock, and long petcock, as pictured above (I believe one of these to be on #8135, from memory - it's full of gas and on the bike which is at the back of the shed so can't look underneath, only see the wrinkles through the filler neck.

The pictures above show the above tanks all to have side wrinkles in the tunnel as well as the ones visible through the neck.

I have a further wrinkle tank which does NOT have the side wrinkles in the tunnel, and is generally more rounded in the way the underside was pressed. Origins of this tank are unknown, except that it is definitely original, not a Yamiya repro. When I can find the camera lead, I'll post a picture. The pad on which the petcok sits is pretty well level with the bottom of the tank, therefore maybe 3/4 mm higher than the bottom welded seam.

Cheers - Chris R.
Chris R.
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kp

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I had a bit of spare time today and after reading the post by Chris I thought I would have a look at my tanks and take some good shots of mid-run and late-run tanks. I won't go into the details but on one of the photos you should note that the rear tunnel wrinkles are further forward than the late-run tank There are other subtle differences between these pressings but for all intents; the petcock pad is the key difference
Chris, last picture is a late-run side which shows no wrinkles, whereas my mid-run has clearly defined wrinkles. That's a good catch you've identified.
Anyway here are the pictures and Wayne, feel free to use what you wish
The mid-run tank is to the right in picture 1 and to the left in pictures 2,3 & 6

KP
« Last Edit: January 18, 2015, 12:21:12 am by kp »
Yabba Dabba KP


kp

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Yabba Dabba KP


kp

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Last one. Chris here is the no wrinkle side
Yabba Dabba KP


4pots1969

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All these small insignificant details in 1969 are today very very interesting!!
There should be several manufacturers in subcontracts for the manufacture of the wrinkle gas tank?? ???
Who can give other explanations?
« Last Edit: January 18, 2015, 06:55:27 am by 4pots1969 »