JASO FB oils are defined primarily for high lubricity performance without any low-smoke and exhaust system blocking technology. They are designed for use in two-stroke motorcycles and small engine equipment.

The main physical, chemical and engine test requirements, according to the current version of the standard (JASO M345:2018), for JASO FB oils are shown below:

Physical and Chemical

Requirement Methods Unit Limit
Kinematic Viscosity (100°C) D445/K 2283 mm2/s 6.5 min.
Flash Point D92 or D93/K 2265 °C 70 min.
Density (15°C) D1298/K 2249 g/cm3 Report
Pour Point D97/K 2269 °C Report
Colour (visual inspection) D1500   Report
Sulphated Ash D874/K 2272 % mass 0.25 max.
Phosphorus D4951/JPI-5S-38-92 % mass Report
Nitrogen D4629/K 2609-1990 % mass Report
Sulphur D2662/K 2541-1992 % mass Report


Engine Testing (JASO FB)

Evaluation Item Test Method


Standard Index

Honda Lubricity (LIX) JASO M 340 103 min.
Initial Torque (TIX) JASO M 340 98 min.
Honda Detergency (1 hour) DIX JASO M 341 65 min.
Suzuki Smoke (SIX) JASO M 342 45 min.
Suzuki Blocking (BIX) JASO M 343 45 min.


The significance of the index numbers:

The numbers for each evaluated item, i.e., Lubricity, Initial Torque, Detergency, Smoke and Blocking are all index numbers which are associated with performance in each category.  Basically, the higher the number, the better the performance in that category.

For more information on JASO FB, contact your Lubrizol representative,