Hi Mr.moose.
I think the fan you have has almost the same effect as the assassin fan. if you analyze the fins seriously, the fins gets the air from the engine, blowing it out of the side cover. What we need is a fan that will suck air from the side going towards the engine itself.
Here's a sample picture of what we use on our gy6 engines here in Philippines.
Notice the tha fins in the inner side catches air as it rotates clockwise, and dumps air on the other side, producing greater air inflow.