83 12A, 165000 miles, carb rebuilt 15000 miles ago.
The shutter and coasting vales seem to be working properly and the car runs well at idle , deceleration and normal acceleration. If i rev the engine slowly, the valves will activate at around 1300 rpm and i get the honking sound. I plugged the vacuum lines from the shutter valve switch and it runs great but the backfiring annoys me. If I plug the line from the coasting valve to the air box, but leave the shutter valve operating, will it help with the backfiring and will anything negative happen?

 

it may..the coasting valve's job is to let fresh air into the rear rotor housing during decel to prevent drag due to higher than normal levels of vacuum due to the shutter valve shutting off air/fuel mix to the rear rotor. backfiring is pretty normal for the rotary engine. just ask any SA owner.