Here is a picture of the Model 1250 with a fresh coat of paint. It has dulled a bit over the years, but it still looks good enough to show. It is decently reliable, but does require a little maintenance of some of the electrical contacts. On occasion it fails to provide power to the ignition coil, requiring a little cleaning of the starting lever contacts with a point file.
Also, the governor speed control lever on the side of the Delco has little control over actual engine speed. I fooled around with this problem for quite a while until several other Delco owners advised me that these governors never really worked, even when new.
Delcos are most commonly 32 Volt DC Generators. They were widely used on farms before rural electrification. Some models were equipped with a flat belt pulley so they could do double-duty as a farm engine. These generators were also equipped with an extra knife switch that would stop the generator from charging (seen located on the lower left corner of the control panel above).
If you have a Delco Light Plant, it is not advisable to run the engine for very long without providing some type of load for the generator. If you do, high voltage can quickly build up in the generator windings, damaging them.
Because most Delcos are not voltage regulated, it is entirely safe to use three 12V automotive batteries as a starting source and a charging load(three 12.6V batteries, equaling 37.8V). When run at full speed it is possible to see voltages approaching 50 volts out of a 32V Light Plant. Providing a good electrical load will prevent this from happening.
I use several 32V light bulbs, still available at Marine Supply Stores, as well as a 32V scroll saw to provide a load for the generator. As the system voltage rises I simply turn more stuff on.
Delco made generators in 7,14,32,38 and 100 volt DC Models. The 32V Models are the most common Light Plants, by far.