nearly all primer bulbs are the same in many brands of machines. the two main types are made by Walbro. take it into most mower shops and they should be able to identify. the electrolux group (Husqvarna) have taken over McCulloch so they will have parts list. the genuine part may be more, but its still a Walbro part, so no need to pay premium price
mike brooker, August 2007