Honda CB750 Sandcast

Interpret my Engine Number

Sam · 20 · 9197

Sam

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Here I am restoring my sandcast thinking I have #1629. A friend stops by and swears it is #1621. I've shown it to an expert in sandcasts and he's not sure either. So I submit it to the collective wisdom. Here are a few pics....

First is a pic of the engine in horrible shape when I found it:



Here's a close up after refinishing the cases:



So what do you think? Is that a 9 stamped weirdly or is that a 1 with a circle near it for no good reason?
Ujeni Motors
Sandcast #410
Sandcast #538 Watch the restoration!
Sandcast #6592 All original daily driver.
Diecast #16608



Steve Swan

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looking at your photos, before cleaning the cases, the '1' it's self; the loop appears as part of the '1".  the picture of the cleaned cases, looks like the top of the loop is slightly below the top of the "1" and maybe not connected to the "1" ?

if the top of that loop is not connected to the top of the "1" then i'd say it's unlikely the stamped digit is a "9".  if the top of that loop is connected to the top of the "1", then it could be argued the digit is a "9".

interesting how that loop is so faint....  unless at the time of stamping the stamp was slightly tilted to the right and the loop part of the stamp was not pressed into the metal as far ?   but, then why would the top part of the "1", in particular the horizontal dash, be so distinct ?

somewhere on the website, there may be some pics of "9" font.

KP has collected vin font examples, i'm sure he'll reply.

does your title use a frame or an engine vin ?  not that it would help, back in the day, some states used engine vins.



kmb69

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The loop of the "9" appears to be the correct Honda font.
However, I would suggest that this may be another Honda factory corrected "mis-stamp".
Certainly appears to have started out life as a "1" and changed to a "9".
The down leg appears to have been double stamped when compared to the other "1"s on this pad.
Might explain the "light" loop on the 9. The stamp kind of fell over into the existing 1.
My $$$$$.02


Sam

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The top case before being painted:

Ujeni Motors
Sandcast #410
Sandcast #538 Watch the restoration!
Sandcast #6592 All original daily driver.
Diecast #16608


kmb69

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Those cases are looking real nice.
What paint are you planning to use?
Please post pics after paint.


Sam

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Painted:



And cured:



I used Duplicolor Engine Paint (Cast Aluminum Coat 1650). I've used it in the past and been very happy with it.
« Last Edit: July 08, 2014, 02:36:42 pm by Ujeni »
Ujeni Motors
Sandcast #410
Sandcast #538 Watch the restoration!
Sandcast #6592 All original daily driver.
Diecast #16608


Steve Swan

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ditto what Keith said about factory corrected vin mis-stamp.  to me, the "1" and the loop appear two different operations because the top horizontal "hook" of the "1"  'appears'  to be a deep and obvious part of the"1".  The loop is faint in contrast to the "hook."

i used duplicolor cast alum.eng.coat 1650, on E2241.  after 1000 miles, seems to be holding up reasonably well to engine operation.  however, it does not 100% withstand heat, gas and oil, even after oven baked on.


Sam

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Ok, so it sounds like this is likely #1629 and that someone didn't do a great job of stamping it. I can live with that  ;D

On the engine paint...I have used this paint on many bikes and so far all of them are holding up very well (thats after around 100k miles across three bikes). There are better options I would imagine, but the color is very close to original and the performance is good enough for me! Curing it in the oven appears to be much better than allowing it to cure with the engine running. Ask me how I know  ::)
Ujeni Motors
Sandcast #410
Sandcast #538 Watch the restoration!
Sandcast #6592 All original daily driver.
Diecast #16608


Erling

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Just out of curiosity: As my evin 1638 is cast 5-19 and yours is just 9 numbers earlier, what date does it have.
I can't find any interest in this dating anywhere, and still there seem to be e few replacement cases where it might do a bit to their age.
It was very few danish sand cast owners I met in the day. We did not name them sand cast then. 
5 bikes were said to have come to Danmark by mid august.
One did I meet by the Belgian GP '71. He had had to wait a whole summer (1970) for a new crank case after he broke a chain!
Sorry in those days I paid no interest in vin numbers.
Only the bike the dealer took on to the street for me to hear: e vin 777!
But I couldn't have that one. He wanted it for himself. The 3 others had already been forwarded to the west of Danmark.
The one I could not have was sold after all. I met the rider one day and indeed he said it belonged to his fiancé!
Never saw it again or heard about it.
Heinrich did not turn up in Belgium next year. His friend, on a ko I believe, had taken over the remains from the insurance after a frontal meet with a truck/lorry.
    Erling.


Sam

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Top case casting date is 5/23:

Ujeni Motors
Sandcast #410
Sandcast #538 Watch the restoration!
Sandcast #6592 All original daily driver.
Diecast #16608


ken736cc

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Hi,
 Here is an example of factory stamped #9
I've seen the future, I can't afford it.


Steve Swan

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Ken, GREAT example of a honda 9 font !  

the hard p[art with 1621 or 1629, which ever you prefer is the fact the last digit appears to have been made to look like a 9.

to me, it's very clear, the last digit was/is a 1.  BUT, at some point after the 1 was stamped, somebody added a loop to make the 1 look like a 9.  whether is was a factory modification or after retail sales, we'll never know. 

as Keith pointed out, we've seen some pretty funky, what appear factory vin changes, to exist.

the owner of the 1621, call me 9 has not answered my questions about the position of the top of loop in relation to the top horizontal arm of the isthe top of loop below and or attatched/not attached to the 1 ????

all things considered, until we have factory evidence of vin modification, what clearly exists is a 9 that does not look EXACTLY like a factory 9 font.  were that loop not there it's a no brainer for a factory 1, IMHO


Sam

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Very interesting pic Ken! Thanks very much for sharing it.

My thoughts...

Steve, I think you are on to something pointing out the horizontal dash at the top of the "1". It looks to me like the "9" has it as we'll even though, according to ken's photo, there should be no horizontal dash. Interesting! No title with this bike unfortunately.

My guess:

This case was originally "1621" but was then changed using the correct font to "1629". When and why is was changed, we will never know. I'm inclined to think of it as #1629 for now.

Thanks everyone for he help. Time register #1629 on the site I think!
Ujeni Motors
Sandcast #410
Sandcast #538 Watch the restoration!
Sandcast #6592 All original daily driver.
Diecast #16608


4pots1969

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For me, I would say that it is good the number 1621, I think that 9 was struck in the first one and 1 struck in second to try to mask 9. Certainly following an error of the worker asked to mark the numbers on engines.