diff --git a/speeduino/decoders.ino b/speeduino/decoders.ino
index 7df00abe..c73f9e61 100644
--- a/speeduino/decoders.ino
+++ b/speeduino/decoders.ino
@@ -516,7 +516,7 @@ void triggerPri_missingTooth(void)
                 if( (configPage4.sparkMode == IGN_MODE_SEQUENTIAL) || (configPage2.injLayout == INJ_SEQUENTIAL) )
                 {
                   //If either fuel or ignition is sequential, only declare sync if the cam tooth has been seen OR if the missing wheel is on the cam
-                  if( (secondaryToothCount > 0) || (configPage4.TrigSpeed == CAM_SPEED) || (configPage4.trigPatternSec == SEC_TRIGGER_POLL) )
+                  if( (secondaryToothCount > 0) || (configPage4.TrigSpeed == CAM_SPEED) || (configPage4.trigPatternSec == SEC_TRIGGER_POLL) || (configPage2.strokes == TWO_STROKE) )
                   {
                     currentStatus.hasSync = true;
                     BIT_CLEAR(currentStatus.status3, BIT_STATUS3_HALFSYNC); //the engine is fully synced so clear the Half Sync bit
@@ -555,7 +555,7 @@ void triggerPri_missingTooth(void)
       if( (configPage2.perToothIgn == true) && (!BIT_CHECK(currentStatus.engine, BIT_ENGINE_CRANK)) ) 
       {
         int16_t crankAngle = ( (toothCurrentCount-1) * triggerToothAngle ) + configPage4.triggerAngle;
-        if( (configPage4.sparkMode == IGN_MODE_SEQUENTIAL) && (revolutionOne == true) && (configPage4.TrigSpeed == CRANK_SPEED) )
+        if( (configPage4.sparkMode == IGN_MODE_SEQUENTIAL) && (revolutionOne == true) && (configPage4.TrigSpeed == CRANK_SPEED) && (configPage2.strokes == FOUR_STROKE) )
         {
           crankAngle += 360;
           crankAngle = ignitionLimits(crankAngle);
@@ -700,9 +700,8 @@ int getCrankAngle_missingTooth(void)
 void triggerSetEndTeeth_missingTooth(void)
 {
   byte toothAdder = 0;
-  if( (configPage4.sparkMode == IGN_MODE_SEQUENTIAL) && (configPage4.TrigSpeed == CRANK_SPEED) ) { toothAdder = configPage4.triggerTeeth; }
 
-  //Temp variables are used here to avoid potential issues if a trigger interrupt occurs part way through this function
+  if( (configPage4.sparkMode == IGN_MODE_SEQUENTIAL) && (configPage4.TrigSpeed == CRANK_SPEED) && (configPage2.strokes == FOUR_STROKE) ) { toothAdder = configPage4.triggerTeeth; }
 
   int16_t tempIgnition1EndTooth;
   tempIgnition1EndTooth = ( (ignition1EndAngle - configPage4.triggerAngle) / (int16_t)(triggerToothAngle) ) - 1;