Small Engines (Lawn Mowers, etc.): Tecumseh engine dies on bumps, intake tube, gasket

Question
When I mow the grass and the mower runs across bumpy ground, it dies. Sometimes I can use the primer a bunch of times at then it will restart. I did replace the float and bowl gasket, also replaced the gasket between the engine and "intake tube" that is between the carb and engine.  That seems to help some.

Here are the model no's
917.382781 for engine
143954502. and either (34690A) or (26756)  these from the local repair shop.

Answer
The problem is most likely electrical and comes from you bouncing on the seat.  This causes the seat switch to run intermittently.  There can be to repairs.  First replaced the seat switch and try it.  Then look at your illustrated parts list to see if there is a "delay switch or delay relay".  The purpose of this relay or switch is to allow quick activation of the seat switch, as it would be riding on very bumpy ground.