Mighty Morphin' Power Rangers (1993)

A Friend in Need (3) - S3-E3

Plot hole: Somehow Bulk and Skull know that the Rangers use the phrase "It's Morphin' time" and also reach behind their belts. They're not supposed to know this, unless they know the Rangers' identities (which of course they don't know despite their "efforts").

Master Vile and the Metallic Armor (3) - S3-E30

Plot hole: In this episode Globbor's energy is drained when Alpha stops the Solar Eclipse, and his Energy drains in the sunlight and severed the physical link between him and Ninjor. This is strange because in the previous episode Globbor had no trouble fighting in the sunlight, and the link stayed intact in the sunlight.

Rangers in Reverse - S3-E33

Plot hole: The whole "reverse time" thing is messed up. Master Vile claims that everyone has been changed back to children. So where would the adults we see for the remainder of the series come from? The Rangers are all about 20, and they're turned back into about 10 year olds. Why is Lt. Stone turned back approximately 30 years, into a 10 year old? It can't be that the reversal was different for each person, as Master Vile claims everyone is a child again. Very confusing.