I've just placed an order with JE Pistons for 2 sets of 12:5 Hi compression drop-in pistons for the ninja 250. JE will only custom make 2 or more sets, so I'll have a second set to sell.\n\nStandard compression is 11:6. the pistons come with rings and pins e.g. everything you need to drop them in. \n\n12:5 should give you significant torque and HP improvement thru the full rev range while running on 93 octane pump gas and requiring no jetting changes. \n\n2 sets are costing me $820. Thus, I'm selling 1 set for $420 shipped anywhere in the US.\n\nLet me know via this thread if you are interested.