Ugh, he is really that skinny? You get him from a breeder? I personally wouldnt drastically up his food intake. Maybe just bump his weaned rats up to every 10 days instead of 14 days for a couple months, then push him back. It is getting to be summer which like i said, is when i usually feed my snakes a little more often.
The pics, he doesnt look bad but its kind of hard to see his full body.
And i do bump up the feeding for my snakes when i get them until i feel they are sufficiently 'plump' in my eyes. Then i throttle them back to a normal feeding schedule.