EFI for carbureted Kawasaki Mule KAF-620

I’ve been very interested in NanoEFI since I first came upon it. The first project I want to tackle with EFI is converting my Kawasaki Mule V-twin 620cc engine to fuel injection. It is the most cold-blooded beast I have ever driven–it bucks, farts, stalls, and fights against you in every way until it finally warms up (it always has). Then it runs beautifully.
John Deere uses the same engine in its 445 lawn tractor, and it looks like the fuel injection system uses a single throttle body into an intake manifold that splits to the front and rear cylinder intakes. I am still exploring their system to learn more details.
If anybody else has an interest in converting a Mule to EFI, I would very much like to compare notes and experience with it!

Welcome @jlexon! :wave:

:joy: :joy:

That would take care of a lot of the fabrication. A shared injector v-twin setup is no problem. One obstacle is detecting engine phase, since V-Twin timing isn’t quite even. I’m working on a way to detect phase in software without a sensor. But without that, you’d need to work in a cam sensor of some sort.

Does the EFI system need cam position data if I kept the original ignition system and used the EFI module for fuel control only?

Yes, you’ll definitely want to have some form of phase detection with a shared single injector/intake on dual cylinders. NanoEFI continuously interprets and syncs against the crankshaft signal to determine the 0° reference for injection events. If it doesn’t have a way to know the cam’s current phase, you’ll have random cycles in which timing is flipped 360° offset. In that situation one cylinder sucks in almost two shots of fuel and the other almost nothing due to how V-twins are timed.

With that said though, I have an idea on the drawing board that I’m calling “phase agnostic” timing for 90° twins. Needs more testing before I can say if it’ll be a viable feature.

On single cylinders (or duals with one injector per cylinder) we can get around this easier without cam/phase input.