How long should primer bulb stay firm?

[IDFISHER]

In a properly functioning carbureted fuel system, how long should a primer bulb stay firm after pumping it and not starting the motor?

 

[racerone]

A much miss-understood thing.-----Primer bulb fills carburetors for starting the motor.------Saves the starter motor from doing that.------Or saves your arms / shoulder in case of a manual start motor.------Once motor starts the bulb will not be hard.----And it does not need to be.----It does NOTHING when motor is running !!

 

[IDFISHER]

Sorry, maybe i didn't explain properly. My question is about how long it will stay hard WITHOUT starting the motor. For example: If i squeeze until firm, and then DO NOT start the motor, how long will it stay firm?

 

[racerone]

Does not need to stay firm.----It has done it's job !!!----I suppose it depends on the QUALITY of check valves in the bulb.----As stated clearly primer bulbs are much miss-understood !

 

[Thomas Pointer]

I have found a bulb that goes soft within seconds is fine, as long as it got firm even for a moment. As has been said it did its job. Having said that, with the low price for a replacement, consider it a warning that the limp biscuit is about to expire and buy another.