My adult males are all on every 2-3 week schedules but they're not underfed, and they will still refuse occasionally. I would offer one small rat every two weeks for a few feedings to get him used to the different type and size of feeder, then bump him to weekly for a while if he's still looking overly thin.
Thankyou I will give it a go I’m hoping he takes it first time no tricky needed fingers crossed I will try him and see next week