Looking at just the ECU itself, your engine is generally compatible if it meets these requirements. This doesn’t take into account other component considerations. Just the ECU.
This is a summarized answer.
Any displacement from 1cc up.
As far as the ECU is concerned, engine size does not matter. However, usefulness for very small <100cc or comparatively large >650cc engines is up for debate given that it may become challenging to find supporting hardware outside of typical powersports engine size range.
Must be four-stroke, for now.
Note on two-stroke compatibility below.
Must have a 12V charging system.
Your charging system must capable of at least 2 AMPS stable continuous output. This is on top of what your battery needs for recharging.
Must have a good battery of sufficient size for starting.
If your starter motor causes battery voltage to dip below 6.5V while starting, your battery is already too small or too old. You’ll want a higher capacity battery to prevent Under-Voltage Lock Out (UVLO) and ECU reset. This is a feature to prevent glitching and unpredictable internal component behavior at insufficient system voltage.
Must have a reliable source of crankshaft timing.
Trigger signals from 6V to maximum of 250V are acceptable. The signal does NOT have to be clean 5v logic and can be quite noisy, thanks to internal software filtering. This allows the use of induction trigger modules from stock CDI systems. And even the kill wire off magneto-based ignitions can be used as timing reference with great reliability.
Note: However “dirty” the signal is, it just has to be reasonably consistent from cycle to cycle so noise can be identified and rejected. More info here.
Must have an exhaust pipe suitable for installing an O2 sensor.
A working O2 sensor must be used. Please plan your install accordingly. If the O2 sensor is left disconnected, the ECU will detect this and will not allow the engine to start. External wideband O2 sensors may also be used instead of the included narrowband unit.
Some limited dual cylinder engine configurations will be supported at launch.
Timing for parallel and v-twin dual cylinder engines is already supported in software. However, since NanoEFI has one injector channel you’ll need to be ok utilizing with a single shared manifold/injector. NanoEFI has a single ignition channel, so keep that in mind as well.
Two stroke engines are intended to be supported later. This isn’t a hardware issue, just my time.
NanoEFI is NOT designed or intended to defeat control devices on emissions regulated engines.
Do NOT plan any NanoEFI install on emissions regulated engines in a way that would remove or defeat any existing emission control devices!
The purpose of NanoEFI is to replace old carburetors with a new modernized fueling system. NanoEFI adds new modern control devices to older engines (such as an O2 sensor) to originally carbureted engines where no such control device existed previously.