<![CDATA[The purposes of this research are to: (1) design water injection system, (2) know the fuel consumption, (2) know the CO exhaust emission, (3) know the HC exhaust emission on Honda Mega Pro 2009 that used microcontroller-based water injection with variations of distilled water and methanol mixture.The research was conducted in the Automotive Laboratory, Mechanical Engineering Education, JPTK FKIP UNS Surakarta, at Ahmad Yani Street, Number 200, Kartasura. This research used Stargas 898 gas analyzer to test CO (carbon monoxide) and HC (hydrocarbon) exhaust emission. Fuel consumption test used static method with specified engine speed. This research used experimental method. The population in this research was Honda Mega Pro 2009 motorcycles. The sample in this research was Honda Mega Pro 2009 with KC11E1237512 engine number. Data obtained from the testing result are inserted into the table and displayed in graphical form to be analyzed. Data analysis used descriptive quantitative method. The results of the research, can be concluded that: (1)Microcontroller-based water injection system can work properly and correctly. (2) There is a decrease in fuel consumption when use microcontroller-based water injection at 4500 RPM engine speed. The best decline occurred in water injection A60 when 4500 RPM engine speed amounted 11.80% compared with standard condition. (3) There is a decrease in CO exhaust emission on the use of water injection A100 and A90. The best decline occurred in water injection A100 amounted 79.42% compared with standard condition. In addition, there is an increase in CO exhaust emission on the use of water injection A80, A70, A60, A50, and A40. (4) There is an increase in HC exhaust emission on the use of water injection A100, A90, A80, A70, A60, A50, and A40.]]>
