Our 2-stroke systems (except a few) do not have an edvance unit for
There is however some advance/retard during starting to ease this.
The diagrams here shows timing of spark in depencence of engine speed
in our internal sensor systems
- diagram above with 112mm rotor, internal sensor
- below with 103mm rotor), internal sensor
The line zero respresents the angle you set at point of installation
stator and rotor markings with the piston in the wanted ignition
position (say 2 mm before TDC which might be something like 28° or
At start, something below 1200 revs ignition will happen later, nearer
to TDC, here shown in the negative area of the graph. During main
driving revs, say between 1200 and 4000 ignition happens in
about the set timing (zero line) and in higher revs it again drops
back a little towards TDC (the negative area here).
This is something inherent in the material, but corresponds very well
to what a 2-stroke engine would like.