"Absolutely, the DFI 2 strokes
"Absolutely, the DFI 2 strokes are my "new" motor of choice.
Unfortunately only Evinrude (BRP) and Tohatsu have produced motors in the lower/mid horsepowers which restricts your choices - with Merc available in the 75 horse and up and Yami producing only 2 models in the 150+ horse range.
There are two basic DFI technologies out there.
Ev and Yami use the Ficht style which is a high pressure system (fuel is injected into the cylinder at upwards of 1000 psi).
Merc and Tohatsu use the orbit (or orbital) technology which uses a low pressure injector (about 40 psi average but definately below 100 psi).
Back when OMC was first fiddling with the prototypes (prior to marketing their earlier Ficht models) they discarded the orbit style - couldn't get it to work the way they liked and found that it was extremely hard on sparkplugs (which is true - Merc Opti's are notorious for eating plugs in about 50 hours).
Again however, the DFI market is still kinda small and they have only been in the marketplace for a "short while", so there longevity is as big a question mark as that of the 4 strokes.
I do however agree with your theory - they have significantly less moving parts in the powerhead compared to a 4 stroke and "it can't break if it's not there" - so do agree there is less to go wrong with them mechanically.
There was some early "bugs" (OMC's catching fire, Opti's with chronic cooling problems) but those were ironed out by the time the 2003 models hit the dealers.
On the electrical/electronic side however, they are just as complex and subject to the incredibly high cost for computer and electronic sensors should something go "flooey".
But, at least initially, these electronic components appear to be durable.
My one concern with the ETEC (and Yami's HPDI models) is the high pressure system. It just makes sense to me that if you are pressurizing a fuel rail or an injector with 1000 psi something is going to give a little sooner than if it's only dealing with somewhat less than 100 psi.
However, that single concern wouldn't stop me from owning an ETEC.
I had the opportunity to partake in some "real life" tests (OMC/BRP dealer on the Canadian side of Lake Erie was given a 40 ETEC to run for a season on the "workboat") a couple years back so was privy to the raw findings and must say the motor was fairly impressive.
There was a minor issue when running the motor in cold weather (the ECU put the motor in protect mode because the operating temp was out of spec) but a simple reflash by the rep cured that problem.
So, if you are open to owning a DFI 2 stroke I wouldn't even consider a 4 stroke.
If you absolutely want/need a 60 horse, then the ETEC is your only choice.
At 70 horses, Tohatsu's TLDI comes into the picture and at 75, the Merc Opti.
Any of them would be (in my opinion) a far superior choice to any 4 stroke in their horse class..."