a 9.9hp can be converted into a 15hp by putting a 15hp carbi on the 9.9 or the little valve that letts the fuel through can be change to a bigger one off a 15hp but that only makes it a 12hp orso. to make it a 15 you need to change the megaphone or exhast whicth can be done but it is very hard. this gives it more power just like when you powerband on a motobike
a pring works by helping u get 99atack 99hp 99str 99def in 30minutes instead of taking u to get all these stats 99 in 3hours
Not nearly as much as an S&S 96ci... out of the box an S&S (V96) has 99hp & 109ftlbs or torque... and it's a more reliable motor....
You have to be doing the quest: A soul's bane to hit the hit of 200 (Members Only.) Otherwise is would be around 60-90 with a armadyl godsword (Sources from Old answer) requiring 99 str, 99 att and 99 def (99hp would be recommended)