This kind long winded...
The Ficht engine was mechanically sound, the technology was sound, mostly. The problems occurred because there wasn't much experience/knowledge regarding how the combustion process differed from regular engines. Old style 2 strokes burned lots of oil and gas and make a dirty exhaust, and lots of soot or carbon. It would gum up rings and leave deposits, but mostly it was a soft carbon which could be washed away. Also all 2 strokes, didn't matter if carbed or Injected, sent gas/oil/air through the crankcase on the way to the combustion chamber. This oiled and cooled the rotating parts and the underside of the piston. Direct injection comes along. Now only air is passed through the crankcase, no fuel mixed with oil, so no cooling in the crankcase, and oil, and very little at that, is now injected into the crankcase. The oil is what contained the detergents needed to keep a 2 stroke clean. During certain operating parameters, a Direct Injection engine, can run on a very tiny amount of fuel. Idle and off idle, up to about 1700 rpm the inject timing and injector aim permitted a very lean stratified charge type combustion. Unfortunately these conditions also created a very hard type of carbon to form. This carbon would build up under the rings keeping the rings from being able to expand/contract. The lack of gas/oil to flush the carbon out added to the problem, and these engines would score pistons from stuck rings. Another part of the problem was these problems were occurring in an RPM/Load parameter that wasn't even considered a risky range. Evinrude, having built 2 strokes for almost a century did most endurance testing at WOT, the common sense was if it survives, say 2000 hours @ WOT, it would last 10,000 hours at 1/2 to 3/4 throttle. Updates were done to the Mapping of the fuel injection, to timing. New cylinder heads, with a fuel deflector to reduce sooting., even entire powerheads were changed out. Special oils and Detergent Additives(Carbon Guard) were introduced and recommended. The later Ficht Ram and now E-tec seem to have that under control.
Automobiles with Direct Injection are currently going through similar pains. These auto engines are carboning up in areas that never occurred with a carb, Throttle Body Injection, or Multi Port Injection systems. One is carbon building up on intake valves, rarely occurred in older engines , even if you had bad valve guide seals. The gasoline kept them clean. They also tend to soot up the tail pipe exits. On Direct injection engines with turbo chargers, if someone uses Combustion Chamber Cleaner, the harder carbon has been known to destroy the turbine. The only safe way to solve the carbon issue is replace/clean the cylinder head. Fine when done under warranty... however warranties do expire....
Back the Ficht. I had a 1998 150. It was carboning up. it had the gambit of updates, remapping, cylinder heads, complete Ficht Ram powerhead. During the winter after the powerhead I saw an I/O I liked, Trading up was gonna cost me about $9000. Well my Ficht was coming out of warranty that coming season. I figured if the powerhead were to croak it was going to cost about $8000(can) for a new powerhead that could croak again. For an extra $1000, a new bigger boat, new engine(lot more power) 4 more years warranty. So I traded. During the inspection of the Outboard, there was an (interesting score) in one of the cylinders, the powerhead had only 49 hours on it. A warranty claim went on that powerhead so it didn't cost me on the trade.
