diff --git a/firmware/config/engines/custom_engine.h b/firmware/config/engines/custom_engine.h
index 71f537d77f..c658573c09 100644
--- a/firmware/config/engines/custom_engine.h
+++ b/firmware/config/engines/custom_engine.h
@@ -32,7 +32,6 @@ void fuelBenchMode();
 void proteusBoardTest();
 void proteusLuaDemo();
 void proteusStimQc();
-void setHarley();
 void proteusDcWastegateTest();
 
 void setTest33816EngineConfiguration();
diff --git a/firmware/config/engines/harley.cpp b/firmware/config/engines/harley.cpp
index f36c41fb07..aca0e13b67 100644
--- a/firmware/config/engines/harley.cpp
+++ b/firmware/config/engines/harley.cpp
@@ -1,6 +1,7 @@
 #include "pch.h"
 #include "proteus_meta.h"
 #include "harley_canned.cpp"
+#include "harley.h"
 
 static void harleyEngine() {
     engineConfiguration->cylindersCount = 2;
@@ -30,8 +31,8 @@ void setHarley() {
 	engineConfiguration->enableAemXSeries = true;
 
   // total 45 degree odd fire, split across two cylinders mostly for fun
-	engineConfiguration->timing_offset_cylinder[0] = 45.0 / 2;
-	engineConfiguration->timing_offset_cylinder[1] = -45.0 / 2;
+	engineConfiguration->timing_offset_cylinder[0] = HARLEY_V_TWIN / 2;
+	engineConfiguration->timing_offset_cylinder[1] = -HARLEY_V_TWIN / 2;
 
   // work-around for https://github.com/rusefi/rusefi/issues/5894 todo: fix it!
 	engineConfiguration->maximumIgnitionTiming = 90;
diff --git a/firmware/config/engines/harley.h b/firmware/config/engines/harley.h
new file mode 100644
index 0000000000..2a39a8aeba
--- /dev/null
+++ b/firmware/config/engines/harley.h
@@ -0,0 +1,3 @@
+#define HARLEY_V_TWIN 45.0
+
+void setHarley();
diff --git a/firmware/controllers/algo/engine_configuration.cpp b/firmware/controllers/algo/engine_configuration.cpp
index 929b920e91..ce47fc5594 100644
--- a/firmware/controllers/algo/engine_configuration.cpp
+++ b/firmware/controllers/algo/engine_configuration.cpp
@@ -73,6 +73,7 @@
 #include "slingshot.h"
 #include "test_engine.h"
 #include "sachs.h"
+#include "harley.h"
 #include "vw.h"
 #include "vw_b6.h"
 #include "toyota_jz.h"
diff --git a/unit_tests/tests/ignition_injection/test_odd_firing_engine.cpp b/unit_tests/tests/ignition_injection/test_odd_firing_engine.cpp
index 87615aed61..4a62958b5d 100644
--- a/unit_tests/tests/ignition_injection/test_odd_firing_engine.cpp
+++ b/unit_tests/tests/ignition_injection/test_odd_firing_engine.cpp
@@ -1,5 +1,38 @@
 #include "pch.h"
+#include "spark_logic.h"
+#include "harley.h"
 
 TEST(OddFire, hd) {
+	EngineTestHelper eth(engine_type_e::HARLEY);
+	engineConfiguration->cranking.rpm = 100;
+	float cylinderOne = 19;
+	float cylinderTwo = 13;
+	engineConfiguration->timing_offset_cylinder[0] = cylinderOne;
+	engineConfiguration->timing_offset_cylinder[1] = -cylinderTwo;
+	angle_t timing = 1;
+	setTable(config->ignitionTable, timing);
 
+	engineConfiguration->crankingTimingAngle = timing;
+	engine->tdcMarkEnabled = false;
+	engineConfiguration->camInputs[0] = Gpio::Unassigned;
+	eth.setTriggerType(trigger_type_e::TT_HALF_MOON);
+
+	eth.fireTriggerEvents2(2 /* count */ , 60 /* ms */);
+
+	float expectedAngle = 180 - cylinderOne - timing;
+
+	ASSERT_EQ( 2,  engine->executor.size());
+	eth.assertEvent5("spark down#0", 1, (void*)fireSparkAndPrepareNextSchedule, eth.angleToTimeUs(expectedAngle));
+
+	eth.assertRpm( 500, "spinning-RPM#1");
+
+	engine->executor.executeAll(eth.getTimeNowUs() + MS2US(1000000));
+
+	ASSERT_NEAR(-200.0, eth.timeToAngle(-66.66666), EPS3D);
+	ASSERT_NEAR(160.0, eth.timeToAngle(53.333333), EPS3D);
+
+	expectedAngle = 180 - cylinderOne - timing;
+	eth.fireTriggerEvents2(2 /* count */ , 60 /* ms */);
+	ASSERT_EQ( 2,  engine->executor.size());
+	eth.assertEvent5("spark down#0", 1, (void*)fireSparkAndPrepareNextSchedule, eth.angleToTimeUs(expectedAngle));
 }