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Have a 3 year old Poulan with B&S engine. When I prime it, it starts up at very fast RPM speed for a few seconds then shuts off. It seems if I pump the primer more than usual, it might fun a little longer, but then shuts off.

It's not getting any fuel once it starts up?

maxcalvada said:

Have a 3 year old Poulan with B&S engine. When I prime it, it starts up at very fast RPM speed for a few seconds then shuts off. It seems if I pump the primer more than usual, it might fun a little longer, but then shuts off.

It's not getting any fuel once it starts up?

Click to expand...

Has it got a primer fitted to the carb on the metal fuel tank?
Sounds like the diaphragm has had it.

Did you leave has in it over the winter ?
If so take pictures of it as you take it apart .
Soak the parts in carb cleaner , brush off dirt varnish & put it back together .

Has it got a primer fitted to the carb on the metal fuel tank?

Click to expand...

Yes, there is a rubber primer pump above the metal gas tank.

Did you leave has in it over the winter ?
If so take pictures of it as you take it apart .
Soak the parts in carb cleaner , brush off dirt varnish & put it back together .

Click to expand...

I think I drained it before winter, but this problem started last fall, I just didn't get around to taking of it till now.

Yesterday, I took the carb off and cleaned it out with carb cleaner. I've reinstalled it, but now the primer won't pump won't work - not pumping any fuel.

Confused.

maxcalvada said:

Yes, there is a rubber primer pump above the metal gas tank.

Click to expand...

You will probably need to replace the diaphragm between the tank and carb.
The Briggs part no is 795083.

Thanks will replace the diaphragm.

For my own education, why does a bad diaphragm make the mower not work. I read there is a vacuum created in the carb. With a bad diaphragm is there air getting in and undoing the vacuum?