Actually, the kick that the flipper is imparting to the ball is typically a result of the EOS gap being too small when the flipper is all the way up.

What is happening is that the momentum of the ball is causing the flipper to bend downwards slightly (completely normal) to a point where the EOS switch contacts re-enagage and the low-power side of the coil is short-circuited, which then causes the high-power side of the coil to force the flipper back upwards. This effect pogos the ball off the flipper bat. What you want to do if the pogo effect is excessive is to re-gap the EOS switch so that it opens sooner, and thus has a larger gap when the flipper is at the end of its upward travel. However, you don't want to open the gap too far or you will lose power on the flipper up stroke: it's a trade-off.