Mine is due for a flipper rebuild but even so I can get the ball up the ramp most times if the aim is reasonably accurate. As others have advised, a flipper rebuild can do wonders  but it may be worth checking that the correct flipper coils are installed as well. Williams had several flipper coil variants for this generation of pinball each of which had a different 'flip strength'. I've just looked at the manual and it should be a FL-11629 (Blue wrapping), I think blue was the strongest in the range if memory serves...