I was screwed several times and last I recognized that a wrong movement was sold to me in a “mint” Skipper, that I bought many years ago in a time I didn´t know things about movements and my local watchmaker didn´t know it too.  I let him check the movement, looks good and works fine BUT it wasn´t a genuine Heuer movement.

Always! Ask the seller for a pic of the movement before the deal is done.
Then compare with a pic of a definitely genuine movement or ask guys who knows more then you.
If it´s not possible to get a pic before then your first way after getting it should be to a watchmaker to open the watch (or open yourself with a tool, but careful, the scratches are irreparable).

Every time you should check the stamp on the mainplate. Heuer used Valjoux are always marked with MN.

Why MN?
It shows that Montes Novalis (MN) took the Valjoux 773x ebauches and dismounted them, replacing the balance wheel with the golden Glucydur one with barrel shaped arms, then put MN marks on the plain mainplates and added texture on main bridges. Heuer let refining the movements to make it higher quality.
On different watches and movement types it´s under the bridge or on the outside, reference pics should be taken from Onthedash.com (direct link to movements) or Ranfft.
If there is no MN there normally will be a “V” signed by Valjoux itself, or we have seen “WG” on Yema, “WE” on Tissot and “TJ” for Breitling – or even unsigned plates are seen.

So here are some tips which you better check before buying a Skipper. A big thank to Gianluca (raticosa) and Abel (heuertime.com) for details, pics and infos.
The list will be completed frequently, stay tuned.

Heuer Skipper 7754 with Valjoux 7730

  1. ALL movement base plates are stamped with MN
  2. ALL movements have signed bridges (plain and with structure possible)
  3. Compare the different materials of the wheels and balance (golden colored – standard Valjoux has  nickel colored)
  4. Balance arms got different shape as the later Valjoux
  5. Ask the seller for a video showing the regatta countdown is moving every 30secs to know if the rare 2 fingers central wheel is built in!

watch the shape of the balance arms.

 

Heuer Skipper 7764 with Valjoux 7730

  1. ALL movement base plates are stamped with MN
  2. ALL movements have signed bridges (plain and with structure possible)
  3. Compare the different materials of the wheels and balance (golden colored – standard Valjoux has  nickel colored)
  4. Balance arms got different shape as the later Valjoux
  5. Ask the seller for a video showing the regatta countdown is moving every 30secs to know if the rare 2 fingers central wheel is built in!

 
note: don´t be wrong, the bridge is signed see pic below but the foto doesn´t cover it.

Heuer Skipper 73464 with Valjoux 7734

  1. ALL movement base plates are stamped with MN
    (MN on the left side of mainplate stamped only for bridge marked but with different font, standard balance wheel are found ONLY on the 73463 and 73663 military – black dial with applied tritium)
  2. ALL movements have signed bridges (plain and with structure possible)
  3. Compare the different materials of the wheels and balance (golden colored – standard Valjoux has  nickel colored)
  4. Balance arms are no straight/plain on Heuer, they are wider to the middle
  5. Ask the seller for a video showing the regatta countdown is moving every 30secs to know if the rare 2 fingers central wheel is built in!

credit: left shucktheoyster

Here is an example of a non genuine and a Heuer Valjoux 7734 movement. The not correct parts are marked in the left pic.

Heuer Skipper 1564 / 15640 with Heuer calibre 15

  1. ALL movement base plates are stamped with SX
  2. ALL movements have signed bridges (plain and with structure possible)
  3. Compare the different materials of the wheels and balance (golden colored – standard Valjoux has  nickel colored)
  4. Ask the seller for a video showing the regatta countdown is moving every 30secs to know if the rare 2 fingers central wheel is built in!

 

About the movements

Just to know: Valjoux 7730 is the 1966 following movement to the Venus 188 (built from 1948-1966) after the take-over of Venus from Valjoux in 1966. The main difference is the cheaper cam-switching instead of high-end column wheel. Yema was one of the first that uses the Valjoux 7730/7734/7736 as substitute for Valjoux 92/72.

Variants: height: 6,00/6,65 mm | diameter 14 line (31mm) | 45 hrs power reserve | 17 rubins | 28.900 A/h (4Hz) – all variants were built over 2Mio. pieces

7730: basic version, built 1966 – 1973, 175k pieces
7731: like 7730 but with new balance piston
7733: redesigned 7731 in 1969-1978 with different reset hammers
7733S: 7733 with regatta-module disc drive
7734: date wheel, not quickset
7736: chronograph with 12 hrs counter (built 1969-1978)
7737: with 10min regatta countdown (for example in Memosail)
7750: 1974-1975 and from 1985 resuming the production till today

Knowledge about the Evolution of the reset hammer 8220 in Valjoux V773x family by Gianluca

Just in case you wonder, why the hammer got a different shape on your movement here is an overview about the reset hammer executions of the Valjoux 773x movements.


From left to right

– V7730/32 reset hammer, fixed arms
– V7733/34/36 reset hammer, early one with adjustable arms (via screw)
– V7733/34/36 reset hammer, later one, self-adjusting  (this later one is found after 1974 when Heuer did not use anymore the V773x calibers and switched to V7740 and 41!)