primer plunger

[Spike78]

Hey all sorry if this q has been asked b4 but couldnt find an answer so here goes how much movement are you ment to get while dispersing the primer i only get about 2 or 3mm and no matter how long i pump it, it does not get firmer.
You may ask why i do this but she hard to start first thing and searching though the site im trying the cheep options first.
Thanks in advance.

[BUSHWHACKER]

It's usually around 10-15mm of movement in the plunger.
The diaphram inside could be split and the plunger isn't creating any suction, allowing the fuel to drain back to the tank when the engine is off.
The next time your attempt to start the engine, the fuel pump has to suck the fuel all the way from the tank.

[Spike78]

Thanks there is a screw in the top should i try unscrewing it?
Jest incase someone has tightened it up.

[Spike78]

bit of an up date found small stone under plunger removed now and every morning i need to pump it 3 to 4 times b4 it goes hard then it starts first time result, Now i think i be changing the filter to see if that helps would the toyota one be the best or does it not matter too much?
Thanks