Bel-Ray – Thumper Racing Synthetic 10W-40 4-Stroke Engine Oil

Bel-Ray Thumper Racing Synthetic 10W-40 4-Stroke Engine Oil is built for the high-revving world of modern thumpers single-cylinder, multi-valve 4-stroke engines that live at the limit. This ester-blend racing oil combines premium synthetic esters with refined mineral base oils to deliver strong film strength, reduced friction, and outstanding heat stability. Its designed to keep valve-trains, rings, and pistons protected under the kind of abuse only a hard-running four-stroke can deliver.

Why we like it:

it keeps performance consistent from the first lap to the last. The formula provides smooth, predictable clutch engagement and helps extract every bit of horsepower while minimizing wear. Its clean-running, reliable, and specifically tuned for the demands of racing and aggressive off-road use.

Why itll work for you:

it meets API SN and JASO MA2 standards, making it perfect for both air- and liquid-cooled 4-stroke engines with wet clutches. The ester blend chemistry delivers strong protection against heat and friction while maintaining clutch feel and throttle response. If you ride a 250F, 450F, or any big-bore single that gets worked hard, Bel-Ray Thumper Racing Oil keeps your motor safe, smooth, and ready for more.

Key Features:

• Combines high quality synthetic esters & highly refined mineral base oils with premium additives
• Formulated for single-cylinder multi-valve off-road & racing motorcycle & ATV engines
• Provides great anti-wear protection for valve-trains, rings, cylinders & pistons
• Extreme pressure additives to offer smoother shifting
• Maximum horsepower & consistent clutch performance
• Withstands extreme racing conditions
• Wear protection for valve-trains, rings, cylinders, and pistons
• For riders changing their oil 2-4 hours (mx bikes) or 3500-4000 miles (dual sport)