Editing User:Eric/sandbox/Progressive Refinements (section)

=== 1953 ===
{| class="wikitable"
|+
!Date Introduced
!Chassis No.
!Unit No.
!Modification
|-
|2 Jan. 53
|20-041 712
|518 653
| <u>Intake Manifold</u>
Now: longer shaping of exhaust pipe to cylinder 3/4. Longer jacket casting

<u>Fuel piping</u>

Now: cross section 17 mm<sup>2</sup> dia.

Formerly: 32 mm<sup>2</sup> dia.

<u>Carburetor 28 PCI</u>

Formerly: carburetor 26 VFIS

<u>Clutch cable</u>

Now: Bowden cable. Clutch cable retaining bracket.

<u>Oil bath air cleaner</u>

Now: new type fitted
|-
|15 Jan. 53
|1-0433 397
|525 661
|<u>Carburetor</u>
Now: air correction jet 200
Formerly: 190
|-
|20 Jan. 53
21 Jan. 53
|1-0435 509
20-043 322
|528 095
|<u>Valve play</u>
Now: 0.10 mm
Formerly: 0.15 mm
|-
|20 Jan. 53
|1-0434 991
|from 527 580
up to 529 045
|<u>Oil pump shaft</u>
Now: shaft pressed into gear (in a number of cases)
Formerly: knurled shaft
|-
|21 Jan. 53
23 Jan. 53
|1-0435 491
20-043 414
|531 963
|<u>Oil cooler</u>
Now: position of damping plate offset (noise reduction).
Formerly: strait
|-
|13 Feb. 53
|1-0444 803
20-045 180
|539 380
|<u>Carburetor and fuel pump</u>Now: angle of nipple 40° + 5°
Formerly: 60°
|-
|14 Feb. 53
|1-0400 000
|
|<u>Cylinder head nuts</u>
Now: with sleeves, tightened to a torque or 3.5 mkg
Formerly: 3.0 mkg
|-
|20 Feb. 53
26 Feb. 53
|1-0448 196
20-046 039
|543 500
|<u>Operating rod for heat control sheet</u>
Now: left and right 217.5 and 203 ± 0.25 resp.
Formerly: 221.5 and 207.5 ± 0.25
|-
|25 Feb. 53
|1-0449 850
|545 450
|<u>Flywheel and crankshaft</u>
Now: residual unbalance market
|-
|17 Feb. 53
10 Mar. 53
|1-0446 526
20-047 157
|541 586
551 512
|<u>Clutch</u>Complete. Lobes increased from 3 to 9 (improved centering)
|}