Stupid question for some, but anyone know the working principals behind how these tachs and rev limiters work? I mean what are the mechanics at work here? Thanks

simple electronics man... tach wire is wrapped around the spark plug wire....

basically what happens is almost similar to what happens in the coil... when the magnet passes by the coil the magnetic field builds a charge in the coil.... and if you know anything about a magnetic and electrical current you will know that once it is created it wants to remain...

basically what i am saying is the magnet crosses the coil builds a charge and the magnet leaves the coil... as the magentic field around the coil is removed the charge in the coil wants to keep that field in place so the charge increases substantially... also within the coil is basically a transformer that also increases the charge more.... this massive charge created by creating and then removing a magnetic field gets so intense that it has the ability to jump the air gap in the spark plug to reach ground which is the block of the motor...

same principle for the tach... the intense charge that passes the windings of the tach wire is there and then gone... that creates a charge in the tach wire which is read and converted by the electronics in the tach to an RPM reading...

all that is simply fields and waves....

ever heard the term inertia... once and object is in motion it wants to remain in motion... the same goes for fields and waves... once they are created (in motion) the want to remain until some force acts on them...

So, basically magnetic and electrical impulses are counted. Tach reads these as rpms. The rev limiter sets a max threshold rpm from these impulse readings above which the it will not let the engine go. But how does is limit the RPM's? Inhibits the spark? Chokes the throttle mechanically? Or What?

rev box is basically a resistor that goes to ground when X amount of ohms are overcame, thus killing power to the coils.

Ah, hah!!! Thanks.

BRILLIANT!!!!