Superhead 4V+R 124cc Kit (2-Point Crankshaft)

This kit part uses the Superhead 4V+R cylinder head.

■Superhead 4V+R (1-cam 4-valve) Features
Compared to the large bore 2-valve SP Takegawa Super Head +R, the intake and exhaust valves are 2 valves each, which further expands the valve curtain area, enabling higher intake and exhaust efficiency than the large bore 2-valve.
In addition, the head shape is designed to balance the center plug, valve pinching angle, combustion chamber shape, and port shape in conjunction with the 4-valve configuration, enabling higher power output, and achieving sustained power output characteristics at high rpm, which is the greatest feature of the superhead.
By adopting a 1-cam, 4-valve engine, we were able to make it as lightweight and compact as possible, while at the same time condensing its performance as the most powerful SOHC head.

・New Superhead 4 valve + R body
The rounded cylinder head shape fits well with the monkey style and enhances the custom image of the vehicle.
Barrel-polished die-cast head covers also beautify the cylinder head.

・Valve Features
Valve diameter Intake: 21.5mm x 2 / Exhaust: 18.5mm x 2
Valve stem shaft diameter: 4.0mm for both intake and exhaust
Valve spring
Unequal pitch prevents surging at high RPM.

・IN / EX port features
Port diameters are optimized to match SP Takegawa's 3D shaped manifolds.
In addition, when installed together with the 3D manifold, it enables smooth intake effect from the carburetor to the combustion chamber without any resistance, thus maximizing the performance of the cylinder head.

・Adoption of roller rocker arm
The roller rocker arm maximizes the output performance of the Superhead+R, increasing output in the mid- to high-speed range and maintaining output in the high-rpm range, a characteristic of the roller rocker arm.
Roller rocker arms reduce frictional resistance with camshafts that occurs with slipper-type rocker arms (stock part type)
The cam profile is smoothly followed from low to high RPM by the built-in roller bearing in the rocker arm.

・M8 Spark Plug
The M8 spark plug is adopted along with the optimum valve pinching angle and compact head due to the 4-valve conversion.

■Hollow camshaft (auto decompression mechanism)
The camshafts are supported by ball bearings at both ends to reduce frictional resistance at the camshaft journals.
In addition to the included camshafts, optional camshafts are available, allowing you to change the camshafts to suit your application and enjoy riding performance.
Attached camshaft: 15 / 20D

・Auto decompression mechanism
This reduces the force of the kick start and the load on the transmission when starting the engine, allowing smooth engine starting even with large displacement engines.

■Ceramic plated cylinders / pistons
・HA cylinder, bore diameter 54mm
All-aluminum ceramic-plated cylinders with excellent durability, airtightness, and heat dissipation are used.
The cylinder is equipped with a temperature sensor mounting area as standard.
Cylinder temperature can be measured by purchasing a meter with a built-in thermometer or a thermometer made by SP Takegawa.
For 124cc HA cylinder: M5 temperature sensor

・Piston
A cast piston is used, and the piston skirt is coated with molybdenum to ensure good initial familiarization.

■X-section connecting rods, 54mm longer stroke crankshaft (R-Type)
X-section shape connecting rod is adopted. Forged material is machined and X-section shape is adopted.
Along with weight reduction, sufficient strength is ensured, and buckling stress diffusion and torsional rigidity are greatly improved.
A special bearing with a larger bore diameter of the crankshaft journal bearing is used.
This allows the shaft diameter at the journal, where stresses on the crankshaft are concentrated, to be increased in size from 20mm to 22mm, thereby increasing shaft strength.