Anybody tried running a small diesel on primary propane or natural gas? I've heard tell of large scale diesel gensets or diesel irrigation pumps set up to vary the amount of "power" via regulating the amount of LP or nat gas  metered into the intake manifold.
   Instead of all the fuss and mess converting to spark plugs and an ignition system. The engine just starts and idles on diesel as per normal. The amount of diesel injected doesn't increase above base idle level. The LP or nat gas in the combustion chamber is ignited by the little "pist" of diesel being injected.   

Have a look here.....

CarlB did a conversion to run a listeroid on natural gas. Seems to work well.

http://www.youtube.com/watch?v=AwPPui8Fyi0

veggiefuel