Lubrication is the basic of the engine to work on a motorcycle optimally. The better quality of lubricant , will be better engine's endurance performance. As a lubricant, oil lubricates all moving parts in the engine to prevent direct contact between components made of metal. As a coolant, lubricants must also be able to reduce the heat generated by friction between metals in machine. Many people ignore the maintenance of machine result is decline performance of the engine. From this background, this research was conducted. This study aims to examine experimentally the effect of viscosity and thermal conductivity on New YAMALUBE and used YAMALUBE lubricants on motorcycle performance. Data collected includes viscosity characteristics at room temperature variations, 40C, 50C, 60C and 75C, thermal conductivity at variations of 30C, 40C, and 50C, power, torque and fuel consumption with the distance of 5 km at 40 km / h. From the test results shown the highest viscosity on new oil and thermal conductivity highest on used oil. Maximum power is obtained by new oil with a magnitude of 7.4 HP at a torque of 9.49 N.m with a fuel consumption of 1 liter as far as 46 km and the lowest power is obtained used oil with a large 7.2 HP at a torque of 10.00 N.m with a fuel consumption of 1 liter as far as 41.7 km. It can be concluded from the data obtained that new oil and used oil have varying characteristic values.