Speck, you need to verify what your problem is first. Electrical or fuel? Make sure you have a strong spark at all spugs. You can do this with a cheap spark tester available from your local auto parts store. If spark is good try pumping the primer bulb when it starts to die. If it acts like it wants to pick up speed then you have pin holes in the fuel pump diaphram. With the description you give it could be either problem.