Yamaha YZF-R3 Overbore +2mm “Turbo” Piston Kit 339.43cc 2015/Current


Spears Racing Piston Kits have been winning races and Championships all over the world for over 4 decades. Spears Racing pistons have been in several of the race wins in close course racing and in road circuits in Europe and has won the Isle Of Man TT Twins race several times.


1 in stock

SKU: SP12-320 Turbo Categories: , ,


Spears Racing’s Yamaha R3 2mm Turbo Piston this is the new 3 Ring FSR Slipper Skirt forging Piston. This kit includes pistons, rings, lighter wrist pins, cir clips and weighs 139g per piston . The compression is 10.0:1. Dome features smooth flowing radius, under crown machining (See Picture) to lessen the overall weight. Anti Det. Grooves, Accumulator Grooves, Double Broach Grooves for extreme applications including professional competition.

Spears Racing  has been designing and making race pistons with the State of the Art CNC Machining and manufacturing alliances with JE Pistons for decades. Spears Racing continuous committed to excellence to advance as the industry changes. This commitment has resulted in more forgings specific to certain applications, proprietary treated wrist pins and piston rings manufactured only for us. Each of these aspects has been put through stringent research and development stages to ensure that our product will exceed your standards.

At the forefront of performance, piston manufacturing has been a result of continuous research and development both in the dyno room and on the race track winning championships all over the world. This Yamaha R3 2mm Piston kit will add more torque and RWHP. This design is lighter than OEM and comes with 1mm o/s valve pockets and deeper pockets to allow the Spears Racing Camshafts to fit with this new design.

Utilizing State of the Art CNC machines for manufacturing, along with purpose-designed forgings, while being able to maintain exacting specifications on each and every piston – holding tolerances to millionths of an inch.

Spears Racing recommends using a surface gap spark plug when installing these pistons, You will need to look at your current spark plugs  USA NGK CR8E (recommend using NGK R0045Q-9 ) European NGK LMAR8A-9  (Recommend using NGK R0465B-10 )

“Preferred Performance” Pistons Kits By Spears Racing

Yamaha R3 2mm Turbo Piston Includes the Following:

Pistons x 2

Wrist Pins x 2

Piston Rings x 2

Cir Clips x 4

Detailed install specification sheet.

This Yamaha R3 339.43cc Race Pistons kit will need to be bored and re-plated with a Nickel Silicon Carbide (NSC) cylinder plating process and cylinder services. This NSC process is so superior to factory plating is often used by professional race teams all over the world to re-plate brand new OEM cylinders.


See SP012-320-Guidlines-with-Information


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