I decided to register just because of this topic and the fact you own a DR650
I took a DR650 to Alaska from Pensacola, FL in 2013 and that was a blast. Ive also got a 4 banger duratec 5speed ranger, and have been reading up on how to improve my mileage.
Anyways, I thought Id put out another idea. The injector seems like it could be very cool, but as you mentioned its a pain to prevent it from clogging up. Perhaps you could filter the water with a reverse osmosis setup first? Or maybe run the water through a fuel filter? This may be a really dumb idea- not sure.
Back when I was a kid (late 90s), my dad and I worked alot on an 85 Chevy El Camino. One of the things we did was install what he liked to call "water induction". We took an old antifreeze bottle, a piece of garden hose, a wick meant for an oil lamp, a needle valve (can get them at home depot), and some vacuum line.
1) Put a vent in the antifreeze bottle where the handle was.
2) Cut a hole in the cap and affixed an adapter to slide the garden hose and vacuum line to.
3) Put the wick in the garden hose (which was inside the antifreeze bottle where the water was)
4) Connected the vacuum line at the top (outside of bottle- top of cap)
5) Ran the vacuum line to the needle valve, then vacuum line out of the needle valve to one of the vacuum ports on the carburetor (could run it to a vacuum port in a throttle body too, or use a T where a line goes to operate something else)
Setup> Run the engine and get it warmed up. Start opening the needle valve until the engine starts to stumble, then back it off until it runs right. I remember our gas mileage went up a few mpgs and power was better. We used this simple setup for about 2 years. About every couple months wed "reset" the needle valve when we noticed water consumption was starting to drop (due to buildup in the needle valve). That thing used a lot of water! We didnt even filter it!! I used to laugh when hed come pick me up at school- 75 in southern california middle of the afternoon and here comes the El Camino with steam coming out the exhaust. I would imagine it might be pretty hard on exhaust systems, so keep that in mind..
Maybe you could incorporate some parts of the above into your plan? I will be following your thread
**EDIT** Not sure if a fuel injected vehicle would stumble the same way. I imagine the computer might start leaning the fuel trims as it took on water, but im not sure. I might actually cook up Dad's old water induction and put it on my Ranger. I have an UltraGuage so I could monitor fuel trims to see..