Waste of coal fly ash produced from the coal combustion in power plants (PLTU) is now a major issue that must be addressed. On the other hand, the availability of fuel energy continues to thin, and the amount of emissions released into the ambient air is sharply increase. The activated fly ash of coal as adsorbent pellets can be used to save fuel consumption and reduce emissions. This research was done with some tests namely stationary, road test, and emission test. Fly Ash pellets were packed in a frame and put in the air filter of a motorcycle. So before the air enterred into the combustion chamber, combustion air firstly contacted with the NaOHactivated pellets which were put in the air filter of the motorcycle. The normalities of NaOH used were 0.25, 0.5, and 0.75N. From the results, it was found that NaOH-activated pellets gave higher engine performance. The best fuel save was 34.48% occurred at 1000 rpm (stationary test) for NaOH 0.25N and 0.50N, 22.38% (road test) for NaOH 0.50N, and reduced 15.81% CO and 18.20% HC for NaOH 0.50N. Kata kunci : Fly ash as adsorbent, activator normality, exhaust gas emission