Motorcycles

Motorcycle oils: the wet clutch decides everything

Never put car engine oil in a motorcycle with a wet clutch

This is the error that generates the most warranty arguments in the trade. Most motorcycles share one oil between the engine, the gearbox and a wet clutch running in that same oil. Modern car engine oils contain friction modifiers whose entire purpose is to reduce friction for fuel economy. In a wet clutch that means the clutch slips — the bike revs without accelerating, the plates glaze, and the customer blames the clutch.

The standard that governs this is JASO:

• JASO MA and MA2 — friction properties suitable for a wet clutch. This is what a manual motorcycle needs.
• JASO MB — lower friction, for scooters whose automatic transmission keeps the clutch out of the engine oil. Putting an MB oil in a manual bike causes clutch slip.

Four-stroke

• EVO RC 4T (5W-40, 10W-30, 10W-50) — synthetic, for modern motorcycles, with shear stability and full wet clutch compatibility.
• PRO RC 4T 10W-40 and ECO R2 RC 4T 10W-40 — synthetic for high-performance and racing use, the ECO version on re-refined base oils.
• PRO SPR 4T (15W-50, 20W-50) — high wear protection for engine and transmission at high speed and temperature, recommended for large scooters with wet clutches.
• MAX FSA 4T 20W-50 — for four-stroke motorcycles, scooters and mopeds including multi-valve and V-twin, air or water cooled. The mainstream grade for the air-cooled machines that do the work in this market.

Air-cooled engines in Iraqi summer heat run hotter than the same engine does in Europe, which is why the heavier grades hold up better here than the viscosity charts alone would suggest.

Two-stroke

• PRO RACING 2T — fully synthetic for high-performance engines: superior lubricity, clean burning, low smoke, strong detergency against gum deposits in rings, exhaust ports and spark plugs.
• MAX SCOOTER 2T — smokeless, clean burning, catalytic converter compatible, with dispersants to limit varnish and deposits.
• MAX SUPER MIX 2T — low smoke for smaller air or water cooled engines, suitable for premix and injection systems, at a recommended 2% dilution.

Two points customers get wrong: mix ratio is not a matter of taste — more oil than specified fouls plugs and blocks exhaust ports, less seizes the engine; and a catalyst-equipped scooter needs a low-ash, catalyst-compatible oil, because an ordinary two-stroke oil will block the converter.

Frequently asked questions

Not sure which product a vehicle, machine or fleet needs? Try the Cyclon oil selector, or send us the details and we will specify it in writing.