Despite all efforts to remedy this prob it still persists.
On pressing the primer bulb it does not release. I've tried emptying the fuel tank and disconnecting all the fuel lines and completely emptying the carb, all to no avail. I've never had any problems and the saw was working perfectly ok up until I stopped working to re-fuel. Light rain was falling at the time and I am wondering if water got into the system. If it did that probably is the cause, and how would I remedy that?
It is a B&Q brand chain saw PWR33CCCSA

DAVE BONWICK, March 2008

If the bulb is not returning then either it is not springing out because it needs replacing (it's lost its elasticity - perished) or there is a blockage in the line to the bulb. There is some sort of one way valve that allows fuel from the tank into the bulb and then stops it from simply flowing back to the tank when you push the bulb. check that you can get a flow of fuel from the tank to the bulb by disconnecting the tube from the tank to the bulb. Check that the path into the bulb is not blocked. IF the saw has been sitting a while then you can get a white waxy build up that can be cleaned out with fresh fuel. if solid contaminants have got in (sawdust) wash it out. It may well be that the bulb incorporates the valve and needs replacing.

Martin, May 2008

Your primer bulb may be old and dry and can't return. If you have access to compressed air try blowing the carburetor out after tearing it apart but be sure you get ALL of the parts out so you don't lose them.

David, March 2008