PART SIX - The 2-Stroke Imperials

The 2-stroke Imperials replaced the 4-strokes for the 1972-73 lawnmower
season (the 1973 Range). The move to Victa's own engine was probably
brought about by the advent of the Series 70 Mk2 - the first Victa engine
with a decompressor for easier starting.

The main modification to that engine (for use on the Imperial) was the
addition of an alloy spacer between the cylinder and head. This reduced
the compression ratio; probably in order to smooth the power impulses of
what was a basic loop scavenge engine design. The result was a cooler
running engine requiring less lubrication, with Victa recommending
BP Zoom Outboard (50:1).

The other change was the removal of the air-vane governor from the
G3 carburettor. This was achieved by simply plugging the hole and
removing the small bevel gear set to make the un-governed 3-357
carburettor.

[Linked Image]
[Linked Image]

TO BE CONTINUED ...