this is a sick motor..however, the older 5 port has a better carb...to make the new 3 port ninja a true winner, i suggest the new ebmod power backplate available for the new longstroke os motors...better tunability, better runtime, and considerably more smoother power from bottom to top...ive seen them on ebay for around $75 and if u call ed at ebmods he can hook you up too...he's imo the best engine guy around and he'll also be the first one to tell u that the short stroke os and ninjas are a more desirable motor...ive been snatching up all the 5 port ninjas i can get my hands on recently as its by far my favorite motor ever after being massaged by ed himself!!