Now I'm curious, according to first addition parts list, this early Frame should have:
Starting Motor-E-11-92600-06008-0B-Bolt, Hex, Cap, 6x8-2. (Acorn Nut bolt).
Do they exist or are they a phantom part?
Does anyone own a low number bike with them or have others seen them on original bikes?
Thanks,
DW
I believe it is not probable these acorn hex head bolts were fitted on any
production sandcast including single digit.
The 2014 Japanese book,
"Honda Dream CB750 Four," pp. 27 and 30, shows
early production vin 9/E8 to have flat hex head bolts attaching the starter cover. Other (numerous) magazines of the 1969-70 era picturing (LH) horn units show flat hex head bolts, i see NO acorn hex head bolts shown in any of these pictures, only flat hex head bolts.
I do not believe these acorn hex head bolts are "phantom," i.e., by dictionary definition, "a figment of the imagination."
Page 21, of the June, 1969, issue of
"MOTOR CYCLIST" magazine very clearly reveals 2 acorn hex head bolts on a
late pre-production vin which appears to possibly be 2113, because the bike featured is in front of the West Coast Honda distributor's office building in Alhambra, California.
Page 27, of the July 1969,
"MOTOR CYCLIST" magazine again very clearly reveals the acorn hex head bolts on a
late pre-production bike. (An interesting side note, the tester states he made a 900 mile round trip from LA to Phoenix on this bike.)
If you study the picture (below) taken at the January, 1969 Dealer's Convention at Las Vegas, of the the red
late pre-production bike, you will note what
appears to be the acorn hex head bolts.
Also of interesting note, page 37, January 1969 issue of
"CYCLE WORLD," the starter cover on the
early pre-production bike
appears to be attached by what are very likely JIS head screws.
At the 40th Anniversary meet during 2009, Bob Jameson, while at the factory during March 1969, recalled watching different Japanese artists sketching parts that would be depicted in the Parts Manual. I would suggest the parts these artists were sketching were, at least some of these parts were pre-production parts, including the goofy little wing nut (pn 17910-300-010) seen on page 61, of the print date 69.4 Parts Manual. (Another interesting side note, Bob recalled a number of different artists coming through, all sketching the same parts. Bob said Honda was having different artists from different companies come through to as a way to determine who drew the best sketches that would be in the Parts Manual bid at the lowest price.)
I believe it is important to also know, as i discussed some years back, the sketches we see in these Parts Manuals (and various photos in Owner's and Service Manuals) are
depictions of parts. When studying a Parts Manual, or any other manual for that matter, i believe it is important to know, and to remember, that
a depiction is a representation of a part,
not what the actual part may have actually looked like. An example of a depiction can be seen on page 66 of the 4.69 print date Parts Manual, the lower brake hose is
depicted to have a long neck, when in fact we know these hoses had a short neck.
fwiw, Yamiya used to and may still sell these acorn hex head bolts, i have a pair on on E254 because i think they are cool, albeit until proven otherwise, are incorrect for early or late production vins.