Some years back I tried to catalog all the changes that
occurred in the 1961 vs. 1962-later CB72-77s, which were many back then. If you
are just getting into the world of 250-305s Honda twins from the 1960s, you
might have run across Honda’s photos of CA77 (Early) and CA77 (late) editions.
The same applies to the CA72s, as well, but they didn’t always have completely
parallel changeover periods.
For the sake of the discussion, I am only referring to the
wet-sump Dreams from 1960-67, not the dry-sump models from 1957-60. When
viewing a Honda Dream, the main differences between early and late models is
the shape of the fuel tank and side covers/knee pads, handlebar controls and
the luggage carrier brackets by the rear shocks. Early CA72 models even had a
different fuel tank design than the CA77s, which was a feature that was done
away with when the later model bikes were released.
As an overview, I am
including some preliminary information from my Honda CA72-77 Dream restoration
guide download package available for sale from my website: www.vintagehonda.com
The first generation
CA72-77s were brought over to the US in 1961. I have seen several engines
stamped C77-A1XXX, instead of CA77, which agrees with the production number
charts, posted in early parts manuals. The 1961 versions had the “rear breather”
lump on the top rear of the upper crankcase half. The idea was that crankcase vapors
would be separated, via the labyrinth, inside the round canister-shaped casting
and then some of the solids would dribble out through a small one-way check
valve to oil the drive chain. This feature was used until CA72-110101,
CA77-110900), when it was deleted and the breather duties were taken over by
the top cylinder head cover. Other changes, in the early years, included the
inclusion of a spring-loaded primary chain tensioner in 1963.
Note that the Keihin
carburetors changed from “round bowl” to “square bowl” designs, probably in
1964, so the float bowls and bowl gaskets will not interchange, but you can use
square bowl floats in the round bowl carbs. Nearby, the first generation camchain
tensioners had a left-side adjustment bolt feature which was changed to the
right side after 1963. BTW there were Mikuni carbs fitted to some early CA72s.
Visually, the most
striking differences between the 1960-62 and the 1963-later machines were in
the shape and styling of the fuel tanks, knee pads and side panels. The
changeover came at either CA77-20902 or CA77-20851 (CA72-20250 or CA72-311110),
depending on which resource you read. However, in reality, the changeover took
place somewhere in the middle of the 1963 production run. The early tanks swept
more forward and the fuel crossover fittings were at the front edges of the
tank, whereas the later tanks used a more central location for the crossover
tubes, adjacent to the petcock location. It has been noted that during the 1963
production run (which is when the cross-over from “early” to “late” models were
transformed) Honda added a 5 into the engine numbers to differentiate the two
series of bikes, so the “late” 1963 engines appear to be exactly 5,000 numbers
higher than the chassis, however the end 5 numbers continued to be within a few
hundred of the frame’s last 5 digits.
1963 was the only year
where they added a 1 into both the engine and frame numbers in the beginning
sequence, so you will see them shown as CA77-31xxxx or CA77E-311xxx. You really
DO have to check your 1963 serial numbers against the parts listings to see if
certain parts qualify for installation, depending upon whether the bike is an
early or late model.
The 250 tanks used different
shaped tanks/side covers. The “frog eye” side covers brought the plastic tank emblems
out to a more vertical positioning than the 305 emblems, which laid on the rounded
surface of the tank panels. The 250 tanks also featured a chrome strip that covered
the central tank seam. Early tanks had seamless fuel tanks with a central fuel location,
whereas the later seamed tanks located the filler hole at the right side of the
seam, which allowed for easier filling when the bike was on the side stand.
Another small change was that the HONDA emblem was not used on the bottom of
the headlight shells until the “Late” models were introduced. Also, the rubber
front fender packing and chain guard inspection hole covers were gray material,
changed to black for later versions.
The handlebars and
controls were another visual change from the 1962 machines onwards. Pre-1963
bikes had twist throttles, where the throttle drums pulled directly on the
throttle cable, which exited from the bottom of the throttle housing, like
those of the CB/CL72/77s. The mirrors were mounted on a set of clamps, separate
from the lever brackets. The handlebars
and mirror clamps were all 257 coded parts, carried over from the CE71 models.
After 1963, the throttles
cables were routed inside the handlebars and the throttle drums had a large
internal spiral, which acted upon a sliding piece inside the handlebar, which
was slotted to suit. The throttle cable was anchored with a small holding piece
and then a separate sliding piece engaged the tip of the inner throttle cable. The
sliding piece engaged the internal spiral of the throttle drum and was pulled
outwards as the throttle drum was rotated. This arrangement made for excessive
amounts of play at the throttle and either disengaged or jammed in one position
if the parts were not lubed and adjusted properly. It becomes difficult to
“feel” the throttle settings with this system, especially when referenced to
the original cable system.
The post-1963 clutch and
front brake cables gained shiny, chromed elbows, which held the cables out and
prevented kinking to a certain degree. The new mirrors were mounted into new
lever perches, eliminating the crowded look at the handlebar ends. Honda was
now able to use the same mirror set (derived from the CA95s) on all 250-305 model
machines, including the CB/CL72-77s.
1963 also seems to have
marked the passing of the tire pumps, which were bracketed on the left side of
the frames, prior to that time. The same tire pumps were carried on CA95s,
CB92s and all 250-305 Dreams up to 1963. Some controversy exists about the fuel
tank badges, as the early ones were marked “Honda Dream 250” or “Honda Dream
300,” whereas the 1964-later bikes all had either “Honda 250” or “Honda 300”
markings. The 1964 badges carried a -279 product code, which indicates a Honda
CY78 parts source. In the US, that was the only part on the machine that
carried a 279 code part, but all of the chassis began to carry a CA78 serial
number thereafter, even though the engines were always marked as CA77!
Batteries are often a
challenge to locate for the early bikes, as they were tall, thin and wider than
the CB72 batteries that Honda decided to install in the 1966-later machines.
The early dry-sump Dreams had 6v systems, but all of the wet-sump bikes have
12v electrics. The starter motor and related parts are all interchangeable with
those of the CB72-77 machines.
The first wet-sump Dreams
came equipped with tiny rectangular tail light assemblies, which featured a
single, unique, double-ended bulb that resembles an automotive interior light
bulb. The tail light brackets were welded onto the rear of the fender sections.
The long, dual lamp filaments proved to be quite fragile (especially when subjected
to the tingle of the engine at certain rpms) and the illumination was less than
satisfactory, at least for US standards. While 1962 models were equipped with
the tiny tail lights from the factory, AHMC wound up replacing them at the
dealerships with a “short lens” version of the CB72-77 268-code tail light
assembly. By 1963, new bolt-on tail light brackets carried a generic “long
lens” version of the CB72-style tail light assembly. Many early taillights were
replaced by dealers as part of a factory update/recall of sorts.
Visually, the front and rear rims and hubs
seem identical, but there were some subtle dimensional differences between the
two, so there are separate part numbers for the two different rims. At the rear
of the chassis, the “luggage carrier” components which fit around the upper
rear shock ends were extended in the “late” versions to incorporate turn signal
lights when used outside the US. Small flat plates were used to blank off the
openings for the American market models.
Three different rear hubs
were designed, incorporating two types of rear cush-drive dampers. The sprocket
carrier is held into the swing arm by a long sleeve nut, allowing for removal
of the rear wheel/hub assembly for tire maintenance without having to remove
the chain guards, sprockets and drive chain. The sprocket carrier has provisions
to incorporate four molded rubber dampers, which engage with four matching drive
paddles cast into the hub assembly. The early style dampers clipped onto the
edges of the carrier, while the updated ones had little extruded extension
tips, which were
pulled through small holes
in the sprocket carrier and snapped in place. The early style brake backing
plates had grease-fittings installed to allow for lubrication of the brake
cams.
Dream mufflers are now a
very scarce commodity, plus there were several versions of Dream mufflers
installed over the years. Originally, the Dream mufflers came with a sharp edge
on the inlet side, onto which a “sleeve” gasket was placed. This gasket had a
lip on one end to help seal and secure the “muffler packing,” as it is called
by Honda. These early generation 1962-63 mufflers were made from stainless
steel, instead of chromed steel used thereafter. Next, we find that the inlets
were modified to house some small, circular O-rings, which had some chamfered
lip sealing edges cast into the design. These early mufflers were all “two-piece”
style, employing a separate header pipe to connect it all together.
In 1966-67, Honda tried to
join the headers and mufflers together, using a crimped sleeve connection, which
was spot-welded onto the header pipe. The flare on the header inlet
necessitated a new design for the exhaust pipe joint (flange) and new split
collars (from the CL72) to help join it all together. Additionally, a special
engine bolt was created to help stabilize and locate the left side muffler onto
the chassis, so there was quite a lot of work and expense to install the new,
replacement “one-piece” muffler sets.
Two different types of
standard low mufflers are seen for Dreams, including ones with deep recesses on
the left side to give clearance for the end of the centerstand. The normal
US-type don’t use this recessed area design and, of course, they both have different
part numbers. Mufflers of all types are now extinct from the Honda factory, but
a firm in Australia has taken the time and effort to make tooling for
replacement mufflers, created in stainless steel. These new mufflers have a
welded-in baffling system, but are still the two-piece design, which is
generally found on most 250-305cc Dreams anyway.
The
-259-code, two-piece Dream mufflers were given a -272 (CIIIA72) product code
designation, as the one-piece part. EPA/DOT-stamped Dream and Benly SS (and
other) two-piece mufflers usually carry a -017-suffix code, although the CB
units carried a -325 number. Mysteriously, while the last replacement mufflers
for Super Hawks were all one-piece versions, Honda discontinued the -272- Dream
units and went back to supplying 2-piece mufflers (usually the -017 version),
until they were discontinued altogether.
Here
are sequences of the part number changes for the 250-305 Dreams:
RT. 18310 (LT.
18330)-259-010/020/027/315/017(EPA) 2-piece
Dream
RT. 18300 (LT.
18400)-271(272)-000 1-piece Dream
Most rare are the mufflers
for the CS72-77 machines, which were only sold in the US for one year, it
seems. While the dual upswept headers/muffler sets looked almost identical to
those of the CS71-76 dry-sump machines, there were differences in the sweep and
angle of the header pipes and some of the bracket locations on the mufflers
were slightly altered. Many parts on the Dream Sports were re-engineered to
complete the installation. Among those items were: footpegs, side covers (split-
horizontally), center and side stands.
Wet-sump Dream speedometers
were sourced from Yazaki and Nippon-Seiki, originally. A few individuals have tried
to make silk-screen or computer-generated overlay faces for the meters, but
only a few speedometer shops seem capable of repairing either style
successfully. As with most other early model Hondas, the high beam indicators
didn’t come standard on US spec bikes until 1964, so numerous
speedometer faces are
necessary to cover all applications.
The ignition switches for
Dreams can be found in either 5-position or 6-position types. US-spec bikes
have the 5-position switch, whereas the Euro models, which had an extra
running, light inside the headlamp, used the 6-position switch, so the running
lights could be used as a separate function. All US machines came with sealed-beam
bulbs, but the domestic/Euro models had separate, replaceable headlight bulbs,
along with the previously mentioned running light. Turn signals (or “winkers”)
were never a part of the US specifications for any Honda street bike until
1968, so finding parts for the signal system on bikes that found their way into
this country has been quite a challenge.
I have an all original 1964 CA78 and it has the stainless mufflers. They're beautifully made and surprisingly light! It also doesn't have a high beam indicator in the speedo or the chrome elbows on the brake and clutch cables...Also, the tank badges say Honda Dream 300 so my bike is quite a mutt!
ReplyDeleteWhat are the serial numbers for your Dream? It sounds more like a 1963-earlier machine.
DeleteBill,
ReplyDeleteI just inherited a 1964 305 Dream. Been sitting in a shed in Sacramento since 1977. I've ridden/worked on dirt bikes since '72, but this one is quite different. I'm tearing it down now in my garage for a frame-up restoration and have been searching on the internet for sources to buy parts such as rims, spokes, tires, chain cases, etc. and have been successful to a point. What/where would you suggest I buy original style mufflers? It had some aftermarket trumpet shaped mufflers that were 60% rust. Also, any suggestions on the carb would be appreciated.
Thanks for your help.
Ken Marrs
Contact me directly at www.vintagehonda.com and scroll to the bottom for contact details. The only thing close to original style mufflers are stainless steel versions made in Australia by Overlander. I'm not clear on what you are referring to on the carburetors. They can be rebuilt with available kits, but don't use the #130 main jets supplied in some kits.
DeleteBill, What's wrong with using a 130 main jet..to much fuel..
DeleteI don't know the reason why Keyster decided to make a #130 main jet as standard for the 305 Dreams, but it clearly is too large for that size carburetor and engine configuration. It might work if you had a modified intake and exhaust system, but the #120 is the stock main jet for those models in factory configuration. I have had numerous questions from Dream owners about why their bikes were fuel-fouling spark plugs and the answer was always a #130 main jet from the carb kits. Dropping back to #120 solved the problem.
DeleteHi I'm in UK and have just purchased a 62 ca72 250
DeleteHi also just purchased a 62 CA72 in UK, US import up and running on historic plates
ReplyDeleteHello, I recently purchased a 1968 Dream. Frame is; CA78-1034066 and Engine is; CA77E-1034128. I've read conflicting information on if they should or should not always match. I think the bike is a 1968 (Mfg in 1967) but I'm not sure. It's in nice shape, runs and drives well and I love it but I would like to know a little more in depth information going forward for parts etc. Any information you can offer will be greatly appreciated.
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