To get the absolute maximum power out of Yamaha's YI-3 engines, this 62mm Ø Naraku cylinder head is indispensable. More passage, reinforced valve springs and larger valves (21/23mm) let every cylinder with 62-64mm bore breathe properly. The use of another injection device like the Malossi Force Master II is absolutely mandatory!
Note for use with Yamaha MT and YZF models from 2014 onwards
The cylinder head has no possibility to mount the Lambda sensor. In any case, this results in a fault in the control unit. Unfortunately, a solution to the problem involves considerable effort: We recommend drilling a hole in the exhaust manifold and welding on a nut to fix the Lambda sensor directly in the manifold. Please note that the sensor must be mounted as close as possible to the cylinder head!
combustion chamber: 62mm
Inlet valves: 23mm
Exhaust valves: 21mm
Scope of delivery
Inlet & exhaust valves
Valve springs, valve stem seals, valve plates and blocking stones