ooh, how does ether kill the engine? i know they aren't designed to run in the stuff but just to get it to fire then the diesel will take over with the added heat.....Once a ether baby, always a ether baby. Guys that is the worst thing for these little engines, it will take them out in a heartbeat. If your having a problem find the problem, don't solve it with ether, because you are going to pay.
I do agree, they *should* start and run on their own, but if the compression is a bit low and if ether is all that can get them to start you really have only 1 other option... a re-build.
I'm really not sure if these have glow plugs either, if they do, that will most likley be the problem, as its hard to start but once running it runs great.