JOG 90 Engine & Cylinder Parts
JOG 90 Cylinder Set 12pin 54mm
Durable iron bore. Stable compression. Ready-to-ride rebuild.
This Cylinder Kit for Yamaha JOG 90 uses a cast-iron cylinder sized at Ø54 mm to support reliable ring seal and steady heat management in daily use. The matched piston/ring set and OEM-fit interfaces make assembly straightforward for routine top-end service or refresh builds.
Highlights
Cast-Iron Durability — Robust wear resistance and stable thermal behavior for commuting and hill rides.
Honed Ø54 mm Bore — Supports quick ring seating and consistent compression after break-in.
Matched Piston & Rings — Controlled geometry helps the engine run smooth with clean sealing.
OEM-Fit Deck & Studs — Cylinder interfaces align with stock cases and hardware for easy install.
Complete Top-End Package — Includes the cylinder gasket for a clean, leak-free assembly.
Product Specifications
✔ Bore Size: Ø54 mm
✔ Cylinder Material: Cast iron
✔ Fitment: Yamaha JOG 90 (confirm year/engine variant)
✔ Type: Top-end rebuild kit
✔ Package Includes: Cylinder Body ×1, Piston ×1, Piston Rings ×1 set, Piston Pin ×1, Circlips ×2, Cylinder Gasket ×1
Installation Notes
Pre-lube and trial-fit; confirm piston-to-wall clearance and ring end gaps to spec.
Observe ring marks and piston orientation arrow; deburr ports if needed.
Measure squish clearance and compression; adjust with gasket thickness or spacers as required.
Torque cylinder/head fasteners in sequence; complete careful heat-cycle break-in, then re-check torque and compression.
For long-stroke builds, verify deck height/port timing and gasket stack before final assembly.
Power You Can Trust.
JOG 90 Long Stroke Bakelite Crankshaft 45mm(+3.0)
Faster primary compression. Longer-stroke torque. OEM-fit build.
This Bakelite Long-Stroke Crankshaft for Yamaha JOG 90 combines Bakelite (phenolic) case-stuffing inserts with a 45.0 mm (+3.0) stroke. The inserts trim crankcase dead volume to sharpen primary compression, while the added stroke raises 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
+3.0 mm Long Stroke — 45.0 mm stroke broadens torque potential after proper top-end setup.
Primary-Compression Boost — Bakelite stuffers reduce case volume for quicker pressure rise off the line.
Cleaner Case Flow — Web shaping helps direct mixture efficiently 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: 45.0 mm (+3.0)
✔ Fitment: Yamaha JOG 90 (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 +3.0 stroke.
Re-map port timing / ignition advance / fueling to suit 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 careful break-in.
Power You Can Trust.