Primer Bulb Question

[Morpheus78]

Is the primer bulb supposed to firm up if squeezed while the engine is running?

I was running at idle last night and the bulb was squishy when I squeezed it when the engine was running.

 

[sschefer]

Re: Primer Bulb Question

Is the primer bulb supposed to firm up if squeezed while the engine is running?

I was running at idle last night and the bulb was squishy when I squeezed it when the engine was running.

That's most likely normal, does it firm up if you squeeze it when the engine is off?

 

[Morpheus78]

Re: Primer Bulb Question

No, it does not.

 

[robert graham]

Re: Primer Bulb Question

Primer bulb is a hand-operated fuel pump with 2 check valves, one in each end, bulb works best if held vertical/up when pumped, after pumping carbs full of gas and the carb float needloes close, then bulb should get hard and system is primed. If my primer bulb did not pump up hard then I would replace it because there has to be some type of leak-down in the fuel system. Good Luck!

 

[sschefer]

Re: Primer Bulb Question

No, it does not.

Do the easiest first. Make sure the fuel tank vent is clear and open. You can just open the tank fill to see if the condition changes.

Next, change the bulb. If it gets hard then you probably cured the problem.

You don't say so I'm going to assume that this is a carbed engine with a pulse type fuel pump. If it's a DFI or EFI engine the following does not apply and I'm not sure why you'd have a bulb anyway.

If the problem persists then first rebuild the fuel pump, the check valve disks have probably sucked through and are leaking.

If that still doesn't fix it then you need to consider a carb rebuild being sure to order and replace the float needles and seats. They are not normally included in a standard rebuild kit.

 

[j_martin]

Re: Primer Bulb Question

Do the easiest first. Make sure the fuel tank vent is clear and open. You can just open the tank fill to see if the condition changes.

Next, change the bulb. If it gets hard then you probably cured the problem.

You don't say so I'm going to assume that this is a carbed engine with a pulse type fuel pump. If it's a DFI or EFI engine the following does not apply and I'm not sure why you'd have a bulb anyway.

If the problem persists then first rebuild the fuel pump, the check valve disks have probably sucked through and are leaking.

If that still doesn't fix it then you need to consider a carb rebuild being sure to order and replace the float needles and seats. They are not normally included in a standard rebuild kit.

Don't get too worried about bad needles until you take a look. A float, a loose seat, a bad seat gasket, or a bit of dog hair in the needle valve or even a bad internal bowl gasket will all look like a bad needle.


get the gasket kits and tear em down. Most likely you'll clean, adjust, and reassemble them to perfection.

hope it helps
John