LP Powered Portable Welder- The Miller Big 40

Background:
This project came up with 2 things in mind, first I needed a portable welder for use on drilling projects for welding our casing together and other misc jobs I might do, and second I like using DC when using a stick welder which is mostly what I use anyway, and besides most of the welding I do is usually in the field and requires a portable unit.

The Details:
I needed a better welder with finer current control than the 1950's GE welder I used for about 2 years. I found a 1976 Miller Big 40 welder which is powered by the widley known Continental F163 gas engine. It needed a little TLC to get it up and running but anyone who has ever used one of these welders knows that they are very good welders. This machine has a 3KW AC generator, and the DC welder can supply 300 amps of continuous welding power. It is a large machine and it is heavy, but they are well built. The smaller air cooled engine driven welders are ok, but they just are not made for big welding jobs and heavy use. I like to use propane to power my equipment so I set this machine up to run on propane using an Impco carburetor which mounts the same as the gasoline carb. Propane is cheaper than gasoline, it runs much cleaner, and it doesn't go bad if it sits for six months. Less expensive fuel costs means lower operating costs, and a cleaner burning fuel.