The Vari-Met CDI module is available in two different configurations. The Vari-Met V2 CDI module contains the new Stage 1 and Stage 2 ignition curves. The Vari-Met Infinity CDI Module is fully programmable via the supplied computer program and also contains a configurable RPM limiter.

The ignition curve partially determines the character of the Sparta-Met engine. The standard ignition curve is far from optimal performance and economical wise and improving this will make the engine more powerful and more economical.

By retarding the ignition timing at low revs, the engine will be more easy to start and it will run more smoothly. By advancing the ignition timing at high revs, the engine will burn it’s fuel more efficiently. As a result of that, the engine will become more powerful and / or more economical.

The current “fast” CDI modules for the Sparta-Met engine advance the ignition time across the whole rpm range of the engine relative to the standard ignition curve. The shape of the ignition curve of these CDI modules will look mostly the same as the ignition curve of the stock CDI module. Which means maximum advance of the ignition timing at low revs and the higher the rpm gets, the more the ignition retards. This is the opposite of what the engine really needs to run at it’s optimal performance.

The Vari-Met CDI module changes all of this. The ignition timing is regulated by a microcomputer which is programmed to give a certain ignition curve. It can have a completely different ignition timing for each engine speed.

The Vari-Met CDI module retards the timing at low revs which makes the engine easier to start and run smoothlier. At high revs, the CDI module advances the ignition timing which makes the engine more powerful and economical. With the Vari-Met CDI module, you never have to make compromise between the ignition timing at low revs and high revs. It can do both.

The Vari-Met V2 CDI module contains two different ignition curves. Every ignition curve is made for a certain type of usage of the Sparta-Met engine.

The Stage 1 ignition curve is made for stock and lightly tuned Sparta-Met engines. (up to about 35 km/h) This ignition curve is easy to use and doesn’t need any other modification. It can easily be swapped with the original CDI module. But as always, please first read the user manual before swapping the CDI module.

The Stage 2 ignition curve is made for light to heavily tuned Sparta-Met engines. This ignition curve advances the ignition more at high revs in comparison to the Stage 1 ignition curve. Because of technical reasons, the flywheel has to be rotated 45 degrees before this ignition curve can be used.

The Vari-Met Infinity CDI module is programmable via the provided computer software. The ignition curve can be adjusted with almost no restrictions. The Infinity CDI Module also contains a configurable RPM limiter. This RPM limiter retards the ignition timing at higher revs to reduce the engine power. The limiter can be configured in such way that the CDI module leaves sparks out above a certain RPM (configurable) range in order to further reduce engine power. 

The speed limiter is easily disabled by connector the black wire, that comes out of the Vari-Met Infinity CDI module, to the engine ground a (configurable) certain amount of time. When the engine is shut off, the limiter will be enabled again. You have to repeat this procedure again to disable the inbuilt speed limiter once again.

The ignition curves of the no longer available Vari-Met Stage 1, Stage 2 and Stage 3 CDI modules, including the optional RPM limiter ignition curve, are shown in the graph below: