
KTM, Husqvarna TPI 2 stroke engine with ecu Synerjet M3C

Today we talk about the functioning of the Continental M3C ecm on 2 stroke engines made as standard on KTM and Husqvarna TPI.
TPI stands for Transfer Port Injection. New TPI engines meet the Euro 4 emission standards.
You can see a 250cc KTM engine in the picture here. The EFI sytem with two injectors into the transfer ports of the cylinder makes the engine much smoother to ride and reduces the fuel consumption. The throttle body is simply a way to control the flow of air into the engine.
Look at the fuel line hanging off the back of the cylinder: one goes to the gas tank and the other two go to fittings in the cylinder’s transfer ports. The two hoses on each side of the cylinder connect to the injector nozzles, which have electrical fittings that go to the ECU Synerjet M3C.
Fuel is injected into the transfer port directly, so that the upward velocity of the air being pump upwards will mist it into the combustion chamber. The oil is also injected and not premixed.
This TPI system works perfect at any altitude and it has an excellent downstream atomization of fuel.


The new ECU can manage ignition timing and fuel, based on information from 5 sensors reading the intake and ambient air pressure, throttle position, oil and water temperature.
The throttle body just controls how much air rushes into the engine via a butterfly valve. It works like the throttle on an internal combustion engine, but there is no fuel in it, not float bowl, no jets, no needles and no nozzles. The throttle body is made by Dellorto.
These are some motorcycles where fuel injection and Synerjet M3C are available:
- KTM EXC/XC/XC-W 150/250/300 TPI
- Husqvarna TE/TX 150/250/300i
- Sherco SC/SE-R 250/300i
What can we do with Continental Synerjet M3C?
We can create bin definition files, also called XDF for free chip tuning software TunerPro.
Here you can read more about TunerPro
Our bin calibration files (xdf) contain the following editable engine maps:
- Fuel: nominal lambda for component protection, target lambda (fuel quantity main calibration).
- Ignition: ignition advance-angle characteristic map (base spark advance).
- Air Calculation: desired airmass flow from throttle by pressure, airmass flow by throttle valve position desired.
- Fans Control: fans activation, fans deactivation.
- Special functions: RPM limiter.
- Quantity of oil for the petrol/oil mixture.
The price of each xdf is 50 euro, Buying our xdf, support on maps remapping, maps’ meaning and TunerPro use are always included.
Some pictures of our bin definition files for TPI engines. The axes of maps reach 11000rpm but engine runs max at about 9000rpm. All Synerjet files are built to achieve higher rpm after appropriate modifications.


