"The Lawn Mower Repair Man's Front Page"
Tip of the Moment; 1/30/00
Briggs & Stratton and Tecumseh primers. They don't all work the same. Primers are used on many engines today instead of chokes. Chokes can be mis-adjusted causing the engine to be either hard starting by not choking enough when they're supposed to or ran on partial choke when they're supposed to be off, and that pollutes.
I'll start with Briggs. If your primer bulb has no hole in the center, push and release several time allowing a second or so between releasing and pushing again. If the bulb has a hole in it, follow the same general pattern but add a second when pushing the bulb before releasing.
Tecumseh has two different appearing bulbs and either can have a hole or no hole. One style bulb is a round dome shape and the other sort of reseambles a little accordion. Thus, you have four styles. The original round dome with no hole is pushed, released--wait a second and repeat. All other Tecumseh styles you need to add holding a second before releasing.
Follow the proper method for what you have and you'll get easier starting. Otherwise the primer will not push enough fuel into the carb throat and starting will be more difficult.