1967-1968 models
These motors have the 2-part disc valve, with a pin retaining the disc. Disc are made in phenolic resin with a steel center.
Samurais have a 2-tone tank with knee grips and white hand made stripe, they came in candy red or blue. Combination unit for tach/speedo.
Side panels are in aluminium grey with a thin “Autolube” sticker.
Avengers  have a chrome panelled tank with knee grips and came in blue. Combination unit for tach/speedo. Side panels are in the color of the bike.
All have a deep, almost valanced, chrome rear fender.
These bikes are sought after because they look… well… vintage! But by the end of 1967, this design was already a bit outdated.

1968 models
Speedo and Tach are separated and round.
new headlight shape, similar if not identical to the early H1.
Tanks keep the previous design but don’t have chrome panels or knee-grips. The paint scheme is the same, with a hand made stripe.
Side panels are in the color of the bike, with a large trapezoidal sticker.
Similar to a 1967 Samurai tank sans knee grips. Red or blue, see my Scrambler to see the color. The colors are different from the previous year and have a LOT of metal flakes in them.
New Stainless steel rear fender, thinner design, will last until the end of production.
Note: these are the models that also were sold in 1969. Think of them as parts bin specials.
Low production run: ~ 1’500 made.

1969 models
New disc using a gear-like sleeve to  link them to the crankshaft. Much better design. The discs are entirely in resin.
the front fork has a new internal design, with new fork ear design, less triangular and with a reinforcement on the inside.
Speedo and Tach are separated and round.
New style (fatter)brake and clutch hand levers.
New style of rear light with round reflector part on top.
New style of hand controls (the markings on the LH are different).
Tanks keep the previous design but has a new oval paint scheme, red or yellow. The red is a very nice shade of candy burgundy. Tank paint scheme was obviously changed mid-year, as there are two different brochures.
New design for the gear changing drum.
New design for the rear swinger, specifically the bush.

350 Avenger gets new 28mm carbs, upping the power to 42 HP and new pipes (with a C engraved, previously there was an A. Don’t know where the B got lost)

1970 models
New tank with a rectangular form. Paintjob is an adaptation of the previous year. The red color is again different, not burgundy, but a “straighter” red. Tank has a recess on top (what for?).
The 250 gets a new head gasket in copper only (previously instead of a asbestos-copper mix).
The 350 has new rings with an expander ring under the 2nd ring. Colors are red or yellow, again different from previous year’s shades.

1971 models
New tank, same shape but no recess on top. New paintjob, white for all models with gradient-like stickers on side of tank and sidecovers.
Accents are blue for the 350 and orange for the Samurai. Last model year before the S1 and S2… End of the line.

If you’d love to agree or disagree with the above, just drop me a line here in the comment section.

This one’s got a sticker over the white original.

Second set shows a Barn fresh example… Pigeon poop and all.

Yellow Tint was for 69 and 70 models, there was a red too. New rear fender shape and incorrect blinkers.

Beautifully restored US model. Note the Grey sidepanel, similar to the early models. It is painted white in 1971 .Look at those pipes! And the Running-in sticker.

A1 is visually the same with the exception of the exhausts and stickers. Note the beautiful blinkers, worth a bloody fortune..