Primer bulb D40 question

[hotshot 5691]

Hello
How critical is the condition primer bulb?.
What are the symptoms if fail to hold prime?.

Mine runs on idle for 2 minutes then cut out

 

[Old.Tony]

The primer bulb is vital. If it's cracked it will allow air to enter the fuel system which may allow fuel to drain back to the tank. An attempt to start the vehicle without fuel present in the pump will cause the pump to start wearing prematurely (the pump uses the fuel as an internal lubricant).