I bought a 2021 MT07 engine from a scrapyard with the wiring harness and ECU for my track car project. Since I didn't receive a key with it, I bought an immobilizer from AliExpress (which works because without it, the fuel pump doesn't prime). Now, I'm having issues starting the engine: when I turn the ignition on, the fuel pump primes, but when I start cranking, there's no spark and the fuel pump doesn't run.

What do you think could be the problem?
What can I do to resolve it?

Edited September 27, 2024Sep 27 by Zsoombikaa

You might try looking at the 'kill circuit' that disallows starting the engine then the kickstand is down, or bike is in gear (clutch switch 'breaks the complete circuit').  Assuming everything else is hooked up, this may be the culprit.

Just a guess, but is the tilt sensor correctly positioned?

But would the engine crank if the safety switches were the problem?

When Yamaha added two extra wheels to the 07, did it corner quicker?

With the 3rd gens, if Yamaha added immobilizers, then you're gonna need that key (with security features) to start the bike, err car.

If it is the immobilizer unit then there's a red warning light in the dashboard and error codes.

Have you simulated or connected the starting circuit cut off relay?

It can prevent the engine to crank by a simple circuit but it can also let the running engine stall when certain circumstances come together (gearbox not in neutral + clutch not pulled + side stand down)

edit: there's a black/red wire between ECU and starting circuit shut off relay. You can try to connect it to engine ground, this is what a closed side stand switch OR gearbox in neutral would do.

Do not confuse it with the two red/black wires in the ECU connector.

Edited September 28, 2024Sep 28 by ElGonzales

On 9/28/2024 at 9:17 PM, ElGonzales said:

If it is the immobilizer unit then there's a red warning light in the dashboard and error codes.

Have you simulated or connected the starting circuit cut off relay?

I don't have the head unit, so I cannot see the error codes of the engine.

As far as I know the starting circuit cut off relay only stops the engine from cranking, but I can crank it all the time.
The problem should come from another source....