Skimmer pump stops and restarts constantly

[ColinD]

So I have a BM NAC5e skimmer, replaced the stock pump with the 'Rock (SP2000) pump' last year, ran great for a couple months and then started to constantly turn off and restart (seemed like every 10 minutes or so). Ran very hot as well, pump housing eventually started to crack and leak so I pulled the skimmer and ran skimmerless for a few months. Decided last month to order another pump and start up the skimmer again, guess what? Its doing the exact same thing, am I doing something wrong? Skimmer runs longer between turning off and restarting 90 minutes or so. Is it possible I got another bad pump?

There's no siphon break or anything like that, skims great when its running.

Colin