2008-Current: Spears Racing 700cc Dirt tracker with a full season on this build,engine has SP17-650K Camshafts,SP07-650K Carrillo Rods, Balanced Rotating assembly,SP700K pistons,Hand ported cylinder head,Bills Built two into two exhaust, Sunoco 112 Supreme fuel.Engine was completely built in house by Gregg Spears. This is a great 1/2 & Miler engine. See Parts on ER/EX650 Bike section 

2008-Current: Superbike Engine built by NKMotors(Germany) using Spears SP01-650K Pistons,SP17-650K Camshafts,SP07-650K Carrillo "H" Beam Rods,Superbike Ported Cylinder Head,Arrow Full Race Exhaust,Race Fuel, Re-mapped ECU. This run is done in the European Correction Factor of DIN, pretty much the same as Uncorrected.The engine configuration is what NKMotorsused to finish 16th @ the 2014 Isle of Man Super Twins.

 ER/EX650 Dyno Sheets