The reason it only runs 2 to 3 seconds is because it is not getting fuel. Once the fuel supplied by the primer bulb is burned, the engine dies. Check the fuel line from the tank to the carburetor. I am also looking for an owner's manual. Hope this helps.
Ramon
November 2008
I can answer this question...
Where do I fid a service manual for a McCulloch Mac 280B Gas Blower?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix chainsaws.