Replace the [SMOKE SYSTEM] entry in your AIRCRAFT.CFG file with any of these:
[SMOKESYSTEM]
smoke.0=0.00, -0.70, 0.00, fx_redssmoke_blue
[SMOKESYSTEM]
smoke.0=0.00, -0.70, 0.00, fx_redssmoke_white
[SMOKESYSTEM]
smoke.0=0.00, -0.70, 0.00, fx_redssmoke_red
Note: the additional settings below are for wingtip smoke, if desired
smoke.1=0.00, -0.20, 15.00, fx_redssmoke_white
smoke.2=0.00, -0.20, -15.00, fx_redssmoke_white