Briggs & Stratton petrol engine.
The engine works fine for various lengths of time (up to 30mins) and then suddenly dies out. when this happens it sucks its own plunger in! (the plunger being the rubber device used to prime the motor before starting) As soon as the plunger is released the motor will restart! My original thought was that the air filter was blocked, however removing the filter has made no differance.
any ideas?