After a quick search on one of the few Mammoth sites, I came across the settings for the XTM 24.7 engine in the Mammoth. Per the manual, the settings are wrong. Apparently, they redesigned the carb on the engine and it now has a LSN factory preset of 3 turns from closed and a HSN that matches (3 turns from closed).
There seemed to be a bit of discussion about this particular problem. Unfortunately, I could not run down an electronic version of their user manual for that engine.
The idle set screw should be set so that there is a 2-3mm gap (about the thickness of a credit card) in the carb barrel when you look down the carb neck.
That should round out the needle settings for you.