JASO MA1 oils are formulated for use in four-stroke motorcycles and scooters and are primarily suitable for wet-clutch applications.
The main physical, chemical and clutch frictional requirements, according to the current version of the standard (JASO T903:2016), for JASO MA1 oils are shown below:
Physical and Chemical
|Sulphated Ash||D874/JIS K 2272||% mass||1.2 max.|
|Phosphorus||D4951/JPI-5S-38||% mass||≥0.08 and ≤0.12|
D892/JIS K 2518
|Sequence II||mL||50/0 max.|
|Sequence III||mL||10/0 max.|
|Evaporation Loss (NOACK)||% mass||20 max.|
(Kinematic viscosity (100°C) after test)
xW-30 : 9.0 min.
xW-40 : 12.0 min.
xW-50 : 15.0 min.
Others : Stay in grade
|High Temperature High Shear (HTHS) viscosity||ASTM D62781||mPas||2.9 min.|
Note 1 : Test shall be conducted by diesel injector method using the standard test conditions (30 cycles)
Clutch Test Friction Properties (JASO T 903:2016(Annex A))
|Dynamic Friction Index (DFI)||≥1.35 and ≤1.50|
|Static Friction Index (SFI)||≥1.45 and ≤1.60|
|Stop Time Index (STI)||≥1.40 and ≤1.60|
Note : MA, MA2 and MA1 shall be within the respective ranges described in the table above for each of the three indices (DFI, SFI, and STI).
Submitter may On-File register an oil which satisfies the MA specifications as a MA or MA1 oil depending on the indices specified and marketing requirements.
The significance of the indices:
|Dynamic Friction Index (DFI)||Measure of clutch feel and how progressively power transfers during clutch engagement|
|Static Friction Index (SFI)||Measure of closed clutch pack torque handling capacity – resistance to clutch slip under high-torque “break-away” conditions|
|Stop Time Index (STI)||Measure of how quickly the clutch engages|
For more information on JASO MA1, contact your Lubrizol representative.