Bel-Ray Works Thumper Racing Synthetic Ester 4T Engine Oil, engineered for single cylinder, multi-valve four-stroke racing engines. Bel-Ray’s Thumper racing oil is designed to withstand the extreme temperatures and stresses experienced during racing.

Formulated with full synthetic, ester base oils and an advanced additive package to minimize cylinder and ring wear, extend bearing life and prevent sludge and varnish formation, as well as carbon build-up, to maximize power and engine life. The racing oil was engineered with high viscosity shear stability to ensure unmatched engine protection, even under the most severe conditions. For engines with wet clutches, Thumper racing oil is formulated for maximum clutch engagement, consistent power delivery, and efficient shifting in any racing environment.

Bel-Ray’s Thumper Racing Engine Oil is compatible with all air and liquid-cooled four-stroke motorcycle engines, including wet and dry clutch applications. The 10W-60 synthetic racing oil exceeds all API SN and JASO MA2 requirements, and is backward compatible for use in applications specifying API SG/SH/SJ/SL/SM or JASO MA/MA1 rated oils.