Burning fuel on a motorcycle will produce 40% exhaust gas wasted into the atmosphere. In motor vehicles, the heat from the exhaust manifold has a temperature range of 25 oC - 590 oC Thermoelectric technology can convert heat from exhaust gas into electricity with the principle of seebeck effect. This research is to investigate the use of water and air-cooled to the electricity generated on thermoelectric. Water coolers use waterblock while air conditioning uses fin and fin installed fan. Thermoelectric using TEC1-12706 type of 12 modules arranged series that placed in prototype heat exchanger on exhaust pipe motorcycle Supra X 125 cc. Tests were performed with variations of water and air cooler and variations of engine speeds idle, 2000 rpm, and 3000 rpm. The loading using a 2.5 volt 3 ampere lamp. The results showed that as increase the voltage, current, and power increased when the engine is turned on and decreased when the engine is turned off. The best engine speed experiments at 3000 rpm resulted in a voltage of 15.05 volts and after being loaded it produced a voltage of 2.92 volts, a current of 0.24 amperes, and a power of 0.7008 watts. In the cooling performance test, the best cooling variation is water with the highest temperature difference of 48.3 oC, no load obtained voltage 23.29 volts and with load 3.68 volts, 0.31 ampere, 1.1408 watt. While the air conditioner temperature difference of 21.9 oC (fin + fan) and 19.8 oC (fin), no load voltage obtained fin + fan (19.56 volts), fin (16.52 volts) and with fin + fan load (2.17 volts, 0.18 amperes, 0.3906 watts), fin (1.48 volt, 0.12 ampere, 0.1776 watt)
