Id direct you here: http://www.msuk-forum.co.uk/topic/3368-how-to-tune-a-nitro-engine/
You can use google to find factory settings just search 'hpi 4.6 factory settings' or somthing
No time like the present to learn some tuning
losi micro T http://www.modelsport.co.uk/losi-micro-t-1-36-scale-rtr-truck-blue-/rc-car-products/27356
or the micro DT: http://www.modelsport.co.uk/losi-micro-desert-truck-rtr-grey-/rc-car-products/34640
Jordan i done some modifications to the shell on my Scorpion after getting tired of grass in the air vents lol:
can you see the mods?
im gonna be using the same mesh on my MGT and cut the grill etc out on the shell