17R-Stage+D Bore Up Kit 124cc HA Cylinder/2B Monkey Gorilla Dax

【SP武川 01-06-0039 17R-Stage+D Bore Stroke Up Kit 124cc HA Cylinder/2B Monkey Gorilla Dax Bore Up Engine Parts Takegawa】
■Product Description
This kit improves the port and fin shapes of the conventional R-Stage+D and adopts a new profile camshaft, achieving even greater output at high RPMs!

■Detailed Description
●17R-Stage+D Cylinder Head
Based on the normal head shape, it uses large diameter valves: intake 26mm / exhaust 22.5mm.
(12V Monkey normal valve diameter is intake: 19mm / exhaust: 16mm)
This is an original SP Takegawa cylinder head that adopts an optimal valve included angle, combustion chamber shape, and port shape in conjunction with the large diameter valves.
While the port diameter of a normal head is 14mm for both intake and exhaust, the port diameter of the 17R-Stage is enlarged to intake: 24.5mm / exhaust: 19mm. In addition, the adoption of a 3D port shape, combined with the larger diameter valves and ports, allows for a smoother flow of more intake and exhaust gases.
Valves: (Intake 26mm / Exhaust 22.5mm Valve stem shaft diameter 4.5mm)
By making the valves larger, the increased weight is kept to a minimum by reducing the diameter of the stem shaft and processing the waist.
Valve Spring: An unequal pitch (two-stage pitch) single valve spring with an optimal spring rate is used to suppress surging at high RPMs.
●R-15E Auto Decompression Camshaft
Auto decompression function: Allows engine starting with light kick force even for high compression, increased displacement engines.
There are three types of camshafts: R-10E / R-15E / R-20E, which can be interchanged according to the intended use to enjoy driving performance.
Camshaft included with the 124cc kit: R-15E
●φ54 HA Cylinder (All-aluminum ceramic-plated cylinder) and Piston
The exterior design is the same as the genuine Cub-type engine cylinder (cylinder height differs).
The HA cylinder is ceramic plated, offering excellent durability, airtightness, and heat dissipation.
An M5 temperature sensor can be connected to the side of the cylinder, allowing for cylinder temperature measurement by using a separate SP Takegawa compact LCD meter (with M5 temperature sensor) or by changing the sensor part of a thermometer to an M5 temperature sensor.
Aluminum forged pistons are used for the piston to improve strength and durability.
●54mm Stroke Up Crankshaft (R-Type) with X-Section Connecting Rod
Uses an X-section connecting rod. Machined from forged material, it features an X-section shape.
This ensures sufficient strength while reducing weight, and significantly improves the diffusion of buckling stress and torsional rigidity.
Special bearings with enlarged inner diameter for the crankshaft journal bearings are used.
This allows the shaft diameter of the journal part, where stress concentrates on the crankshaft, to be increased from 20mm to 22mm, thereby improving shaft strength.

■Compatible Models
HONDA
12V Monkey / Gorilla (Z50J-2000001～ / AB27-1000001～1899999)
Monkey R / RT (AB22-1000017～)
Monkey BAJA (Z50J-1700001～)
12V DAX50 (AB26-1000001～)
CRF50F (AE03-1400001～)
XR50R (AE03-1000001～)
CRF70F (DE02-1700001～)
XR70R (DE02-1000001～)

■Notes
※Images are for illustration purposes only. Includes products with different sizes and colors.
※Product design and specifications are subject to change without notice. Please understand.
※To fully utilize engine performance with the 17R-Stage+D, a separate SP Takegawa carburetor kit and muffler must be installed.
※Installation of the 124cc kit requires crankcase modification.
※When installing the 124cc kit, the engine length increases, and the engine will interfere with the fender or tire if using the normal front fork, normal top bridge & stem. Therefore, modifications to the front end are required.
※This product is made-to-order, so cancellations after ordering are not possible.
※As this is a made-to-order product, it may take some time for delivery. Also, please note that the manufacturer may discontinue the product or change specifications without prior notice.