A standard NE2 bulb fires around 60 volts, so you will need to put two of them in series, which should be close enough for that sort of circuit. A neon bulb with a base probably includes a series resistor and will not regulate very well.

I have a 244.2138 with a blown transistor and diode. Does that information give any identification on that transistor? Thank you!

Moderator edit: New thread created from this.

 

I have schematics for 4 Sears timing lights, model 244.21172, 244.2115, 244.2138 if interested. Two from Sears, the others I reverse engineered. They use either 3 or 5 wire charging transformers, are inductive or not, and the pair of diodes downstream of the charging transformer either point to the Xenon tube or away from it. My question is one model uses the Signalite V139R1.9 neon tube as a voltage regulator for 139 VDC. No longer available. Can a typical neon bulb work as one finds in control switches or pilot lights? I use a timing light on a 1974 Honda motorcycle and 1978 VW Rabbit, both with points/capacitor, they run fine and can be easily maintained.

This may be a duplicate as being a newcomer I may have posted in the wrong place! I have a 244.2138 on which the Transistor and diode in it's emitter are both blown. Does that schematic give any indication as to what the transistor is?

 

Two of the NE2 bulbs in series should be close enough, although I don't know how much current they can draw. And I am wondering what in a timing light needs voltage regulation. Possibly the trigger circuit? The transistor may have been destroyed by a backward connection, or just as likely by over heating. I suspect those lights are not rated for constant operation.