"....the thing under the cover has SIG-01 on it?"
A picture with the plastic WIPAC points cover removed would be useful. A Google on SIG-01 hits http://www.mobiletron.com.tw
They are a Taiwanese OEM manufacturing ignition products and other electrical automotive items. A SIG-01 search on their site throws up:
Part Number : SIG-01
New Ref. Number : MFSG00020
Widely used in 4 and 2 cycles gasoline engines as in:
LAWNMOWERS, GENERATORS, PUMPS, CULTIVATORS, TILLERS,
COMPACT GARDEN TRACTORS, CHAIN SAWS, BRUSH CUTTERS, TRIMMERS
(The SIG-01RP product is a pos or neg ground.)
The data sheet is password restricted (typical OEM) but they do have a UK office up north in Preston. The inference is that this is a CDI ignition switch. The shape partially visible under the Wipac points cover looks very similar to their product picture. So maybe someone has been retrofitting CDI?
Although slightly off topic the SIG-01 google also brings up:
(Dial up download is not recommended.....)
This is an Oz student final year project on â€œDIGITAL IGNITION & ELECTRONIC FUEL INJECTIONâ€