Bel-Ray Thumper 4-Stroke Racing Motor Oil is specifically engineered to meet the demands of single cylinder, multi-valve 4-stroke racing engines. The high temperatures and severe loads of racing require the exceptional film strength, shear- and temperature stability of Bel-Ray Thumper 4-Stroke Racing Motor Oil. NOTE: There are two grades: 10W-40 and 20W-50
BelRay Thumper Oil is the ONLY oil designed specifically for today's modern high output 4 stroke singles such as the CRF and YZF’s.
High viscosity and great anti-wear to prolong engine life.