Takegawa 17R-Stage +D Bore Stroke Up Kit 106cc - XR50 / CRF50 / XR70 / CRF70

Takegawa 17R-Stage +D Bore Stroke Up Kit 106cc

Takegawa has updated this kit and the port and fin shape has been improved from the previous R-Stage+D and offers a new profile camshaft has been adopted for even more power at higher RPMs!!!
Includes a 50mm stroke crankshaft with X-shaped connecting rods.

■17R-Stage +D Cylinder Head
Based on the stock head shape, large diameter valve intake: 26mm / exhaust: Adopt 22.5mm which is much larger than OEM.
Takegawa's cylinder head shape adopts the most suitable valve pinching angle, combustion chamber shape and port shape for large diameter valves.
The port diameter of the stock head is 14mm for both intake and exhaust, while the port diameter of the 17R-Stage is 14mm for intake and exhaust: 24.5mm / exhaust: Larger diameter of 19mm.
In addition, the adoption of a 3-dimensional port shape, combined with the larger diameter of the valve and port, makes it possible for more intake and exhaust gases to flow smoothly which equates to more horsepower.
Valve: (Intake 26mm / Exhaust 22.5mm Valve stem shaft diameter 4.5mm)
The weight increase due to the larger diameter of the valve is kept to a minimum by the narrower stem shaft and waist machining.
Valve Springs: The single valve spring with unequal pitch (2-stage pitch) is adopted for optimum spring rate and suppresses surging at high rpm.

■Includes: Auto decompression camshaft
Auto decompression function: The engine can be started with a light kick force even on high compression and high displacement engines.
There are three types of camshafts, R-10E, R-15E and R-20E, and you can change them according to your application and enjoy the riding performance.
88cc / SCUT 106cc / 106cc kit supplied camshaft: R-10E

■Φ52H cylinder (aluminum steel sleeve cylinder) and piston
The piston has a molybdenum coating on the skirt for better initial adhesion.

■Reinforced crankshaft (2-point crankshaft)
X-shaped connecting rods
Forging material is machined, and an X-shaped cross section is adopted.
It is lightweight and strong enough, and its buckling stress diffusion and torsional rigidity are greatly improved.
Surface shot peened finish.
Strengthening the Journal Department
A special bearing with a larger inner diameter is used for the crankshaft journal bearing.
As a result, the shaft diameter of the journal section, where the stress on the crankshaft is concentrated, can be increased from 20mm to 22mm to increase the strength of the shaft.

Made in Japan

If you have any questions please call one of our knowledgeable and friendly techs at 833-327-8507