JOG 50 Engine & Cylinder Parts

Cast-iron 48mm bore-up—tight seal, stronger low-mid pull.

The JOG 50 Cylinder Kit upgrades Yamaha JOG50 scooters to a 48mm bore. Its cast-iron cylinder body delivers a wear-resistant bore and stable clearances. With proper fueling and head matching, the added displacement supports a more responsive low-to-mid pull, while OEM-fit interfaces keep installation straightforward.

🔹 Performance Potential — 48mm bore supports stronger low-to-mid pull with proper fueling and head matching
🔹 Cast-Iron Cylinder Body — Wear-resistant bore with stable thermal behavior for long service life
🔹 Precision Machining — Honed bore and flat decks for consistent ring seal
🔹 OEM-Fit Interfaces — Stock-layout mounting for accurate, hassle-free assembly
🔹 Complete Kit — Cylinder, piston, rings, pin, circlips, gasket included

Product Specifications
✔ Bore Size: 48mm
✔ Material: Cast-iron cylinder
✔ Fitment: YAMAHA JOG 50 scooters (year/market dependent)
✔ Focus: Durable bore, tight sealing, responsive feel (with proper tuning), straightforward install
✔ Package Includes: Cylinder, piston, piston rings, piston pin, circlips, cylinder gasket

Installation Notes
• Confirm cylinder head and gasket compatibility; set fueling (carb jetting / FI calibration) for the new bore.
• Follow standard ring break-in; re-torque fasteners after initial heat cycles.
• Inspect variator/roller tuning after the first test ride to match the new power curve.

Power You Can Trust.

Video: https://youtu.be/HuavFPBSoSg

Faster primary compression. Longer-stroke torque. OEM-fit assembly.

This Bakelite Crankshaft for Yamaha JOG 50 pairs Bakelite (phenolic) inserts with a 41.4 mm (+2.2) long stroke. The inserts reduce crankcase dead volume to sharpen primary compression, while the added stroke increases displacement potential for stronger low-to-mid pull—once cylinder height, timing, and fueling are set correctly. Precision journals and OEM-matched tapers keep assembly straight and predictable.

Highlights
🔹 +2.2 mm Long Stroke — 41.4 mm stroke broadens torque potential after proper top-end setup.
🔹 Primary-Compression Boost — Bakelite stuffers trim case volume for quicker pressure rise off the line.
🔹 Cleaner Case Flow — Web shaping guides mixture more directly toward the transfers.
🔹 Precision Interfaces — Tapers/threads/keyway match OEM bearings and ignition hardware.
🔹 Build-Ready — Designed for straightforward truing, seal fit, and clearance checks.

Product Specifications
✔ Type: Bakelite-stuffed long-stroke crankshaft
✔ Stroke: 41.4 mm (+2.2)
✔ Fitment: Yamaha JOG 50 (confirm year/engine code)
✔ Interfaces: OEM-match main-shaft tapers, threads & keyway
✔ Bearings/Seals: Compatible with OEM-spec main bearings & oil seals
✔ Material: Forged steel webs & connecting rod, Bakelite inserts
✔ Package Includes: Crankshaft assembly ×1

Installation Notes

• Set cylinder height/base spacer, compression ratio, and squish clearance for the +2.2 stroke.

• Re-evaluate port timing, ignition advance, and fueling/jetting for the longer stroke and higher case pressure.

• Confirm small-end pin diameter and bearing spec match your piston/rod kit.

• Check crankcase/web clearances, measure runout after bearing install, use new seals, and complete a careful break-in.

Power You Can Trust.

Clean seal. Stable geometry. Ready to rebuild.

This Piston Kit for Yamaha JOG 50 is sized at Ø48 mm to match the intended cylinder. The crown and skirt are finished to tight tolerances to support steady running and ring seal, while OEM-fit pin and clip interfaces make assembly straightforward for everyday refreshes or top-end service.

Highlights
🔹 Stable Ring Seal — Matched ring set helps maintain compression after proper break-in.
🔹 True Running Geometry — Controlled crown/skirt dimensions for smooth operation.
🔹 OEM-Fit Interfaces — Pin and clip grooves align with stock hardware for easy install.
🔹 Service Friendly — Clear orientation marks and standard assembly sequence.
🔹 Daily-Use Ready — Built for reliable commuting and regular maintenance cycles.

Product Specifications
✔ Bore Size: Ø48 mm
✔ Fitment: Yamaha JOG 50 (confirm year/engine variant)
✔ Type: Replacement piston kit (complete top-end wear parts)
✔ Focus: Engine refresh / ring seal consistency
✔ Package Includes: Piston ×1, Piston Rings ×1 set, Piston Pin ×1, Circlips ×2

Installation Notes

• Use with a properly honed Ø48.00 mm cylinder; measure piston-to-wall clearance per spec.

• File-fit ring end gaps to tolerance；observe ring marks and piston orientation arrow.

• Lubricate pin/bosses and rings, verify circlips are fully seated.

• Torque to manufacturer spec, then perform careful heat-cycle break-in and recheck compression.

Power You Can Trust.