level guage for small engine

[DougPK]

I want to make a level gauge for a small engine. does anyone know what are the threads on the oil fill plug?

 

[JohninCT]

Can you instead rig it to the drain port. The drain plug is a regular pipe thread (3/8 I think). Best thing to do is take the plug to hardware store and match up size. Thread a short nipple in where the plug came out. Tee onto that. Drain plug in the end of the tee. Level gauge in the center of the tee.