Fuel Injection question - 2011 TE449

My COVID isolation OCD has kicked in and I was wondering how the ECU in this bike determines when to inject fuel based on which stroke the engine is in due to the flywheel sensor providing a pulse every revolution and without a camshaft sensor.

Does it fire the fuel injector every stroke with 1/2 the fuel for each cycle behind the inlet valve ready for the 2nd firing and intake stroke?

Or does it look at the manifold pressure drop?

Time to buy an oscilloscope..

Interesting. Did you work out the answer? Think my 449 has just started with injector or pump issues.

No. I haven’t bought an oscilloscope (yet) to solve the question.

So, I finally bought a Digital Oscilloscope as I'm doing some testing on replacement stators for the 449/511 engines.

The fuel injector and spark fire every second crankshaft revolution. I have since found out that although there is no camshaft sensor, the ECU determines the intake stroke via the manifold air pressure sensor. When the intake valves open and the piston descends, the intake pressure drops so the ECU can the identify the intake stroke.

The fuel injector pulse is small as I held the probe close to the injector to pickup the RF. There's no room to probe it directly.