Hi, while rebuilding my vette, I found the following issue, the ball launched hard into the lane, sometimes hitting the side of the cabinet, prior service tech replaced coil with a 23-800, should be 20-3000 I believe a far weaker coil. Also the plunger assembly was incorrect as well it was the right length but pencil thin not the solid round style. Hope this helps.

Mine would hit the bottom of the exhaust pipe and bounce back into the saucer. I had to add a washer under the pipe to give it some more clearance, and adjust the kickout so it would feed better.

I had this exact same problem. When just one ball was in the lock it would hit the exhaust and bounce back in over and over. When there was 2 balls it worked fine. I raised the exhaust with washers and it works every time now. This only started happening after I changed the coil sleeve for the kickout.

Mine were pretty consistent.
Jathomp. Yeah, mine was the exactly the same. So lesson learned, don't shop out the saucer eject mechanism.

Mine too!

Mine works great. No issues....

Once I replaced the coil and proper plunger assembly for the unit it works everytime whether one ball or more. Check the plunger assembly it is supposed to be the solid steel and plastic of the same size, the one I found in my game was steel with the thinner diameter plastic attached so it wasn't hitting the ball squarely when launching.

I did the exact same thing