Slow Size 3 Starter

[SeafWWTF]

We have a size 3, 8536 SEO starter I in an MCC that recently began blowing the secondary fuse on the control transformer intermittently. I think we’ve narrowed down the issue to the starter being sluggish to engage, especially when it’s been off for a while (I believe the amp draw of the coil is high until the armature has fully travelled, correct?). We’ve tried 2 different coils, a different voltage source for the coils and eliminated any peripheral control devices. We’ve inspected the movement and wear points of the operating mechanism, and they move freely and look good. Ours has the rubber “drop-out pads” which are showing some sign of deterioration and are slightly sticky…could that be enough to hold the armature back? When the starter has been off for a while (cold) and we apply voltage to the coil, the armature seems to “bind” for about 1 second before engaging. It seems to operate faster after the initial engagement (like it’s warmed up). These tests have all been performed with a load connected if that makes any difference. Looking for ideas and suggestions. Thanks!