would this sensor keep 2005 Honda recon from starting? it will turn over but no spark

 

No, the Recon is just about the only Honda Quad to still use pure AC ignition, an exciter coil in the alternator provides the power, a trigger coil outside the flywheel provides the timing and the CDI converts this into a power pulse to the coil.

One proviso, Hondas have a sort of boost system which increases spark when in neutral, so if the CDI doesn't get the signal to say it is in neutral, it won't boost the spark, and often you can't see any spark at all when you spin the engine on the electric starter, strangely, you still get a decent spark using the pull start though.