Sure, it will work fine. Just be sure you set it up correctly. See my drawing/explanation about dwell above. On a 42cc engine, be careful about kickback when starting with this system, as it has no automatic retard. But other than that it will work fine.

The only problem is that by the time you buy the system and the coil, you aren't too far off from being able to buy the basic CH Electronic ignition system dollar wise.

Good luck,

AV8TOR