Been thinking about this again. Most of the air compressors don’t have a thru shaft crank only one side has a shaft. This may or may not be a problem. You’d have to use a lawnmower flywheel and ignition and also attach a pulley. Some weed eater motors only have one shaft. Some have a removable plate on the other side. If they don’t have a full side cover it will be nearly impossible to adapt to a dual shafted crank. You would have to slice part of the case and drill and tap it (if it’s thick enough). It would look perfect on a drop loop style board track bike. Cam and valves are another issue you would have to have pushrod tubes and make or use a new head. It would be sweet building something and hearing it fire up for the first time.