<![CDATA[ABSTRAK Sebagian produksi industri sepeda motor menggunakan sistem pendingin air yang menggunakan aliran air tertutup yang mengalir pada bagian silinder dan head silinder. Fungsi sistem pendingin air adalah menurunkan temperatur mesin yang meningkat karena mesin dalam kondisi berjalan, panas yang timbul dari proses pembakaran dan gesekan karena putaran mesin yang tinggi. Tujuan penelitian ini mengetahui kandungan mineral pada media air, mengetahui laju perpindahan panas pada mesin sepeda motor, mengetahui media air apa yang baik digunakan terhadap laju perpindahan panas sistem pendingin air pada mesin Yamaha Vixion 2012 dan mengetahui pengaruh media air terhadap resistensi, celah gap dan perubahan warna pada busi. Penelitian melakukan analisa langsung terhadap radiator mesin sepeda motor Yamaha vixion 2012 dengan menggunakan media air tanah, air mineral dan radiator coolant dengan putaran mesin 1450 Rpm. Penelitian hasil uji sampel kadar besi (Fe) dilakukan di Laboratorium Analisis Politeknik Negeri Lampung (POLINELA) dan hasil nilai derajat keasaman menggunakan alat ATC (pH meter). Dari hasil pengujian didapatkan nilai laju perpindahan panas pada media air tanah pada menit ke-5 sebesar 1.800 w, menit 15 6.018 w menit ke 30 6.565 w menit 60 6.841 w, media air mineral pada menit ke-5 sebesar 1.726 w, menit 15 5.912 w, menit ke 30 6.529 w, menit 60 6.741 w, media air radiator coolant pada menit ke-5 sebesar 1.800 w, menit 15 6.089 w, menit ke 30 6.512 w, menit 60 6.459 w. sementara pada hasil uji lab kadar besi (Fe) setelah pengujian pada media air tanah 0,004 mg/l, air mineral 0,041 mg/l dan radiator coolant 0,029 mg/l. Kesimpulan pengujian sistem pendingin air mesin Yamaha vixion tidak mempengaruhi terhadap resistansi busi, celah gap hanya warna yang berubah menjadi putih kecoklatan (normal). Media air terbaik menggunakan media air pendingin radiator coolant karena memiliki laju perpindahan panas lebih kecil daripada air tanah, air mineral karena memiliki zat adiktif antibeku yang membuat titik didih lebih tinggi dan titik beku lebih rendah dan zat anti korosi. Kata Kunci: air tanah, air mineral, busi, coolant, radiator, laju perpindahan, panas konveksi ABSTRACT Thermal Analysis Of The 2012 Yamaha Vixion Engine Cooling Water System Using Ground Water, Mineral Water And Radiator Coolant. Some industrial production motorbikes use a water cooling system which uses a closed flow of water that flows through the cylinder and cylinder head. The function of the water cooling system is to reduce engine temperature which increases because the engine is running, heat arising from the combustion process and friction due to high engine speed. The aim of this research is to find out the mineral content in the water medium, to know the heat transfer rate in motorbike engines and to find out what water media is good to use for the heat transfer rate of the water cooling system on the 2012 Yamaha Vixion engine and to know the effect of water media on resistance, gaps and discoloration of the spark plug. The research carried out a direct analysis of the 2012 Yamaha Vixion motorbike engine radiator using ground water, mineral water and radiator coolant with an engine speed of 1450 Rpm. Research on the test results of iron (Fe) content samples was carried out at the Lampung State Polytechnic Analysis Laboratory (POLINELA) and the results of the acidity degree values used an ATC (pH meter) tool. From the test results, the value of the heat transfer rate in groundwater media at the 5th minute is 1,800 w, 15 6,018 w minutes 30 6,565 w minutes 60 6,841 w, mineral water media in the 5th minute is 1,726 w, 15 5,912 minutes w, minute 30 6,529 w, minute 60 6,741 w, medium water radiator coolant at minute 5 is 1,800 w, minute 15 6,089 w, minute 30 6,512 w, minute 60 6,459 w. meanwhile, in the lab test results, the iron (Fe) content after testing on groundwater was 0.004 mg / l, mineral water was 0.041 mg / l and radiator coolant was 0.029 mg / l. The conclusion of testing the Yamaha vixion engine water cooling system does not affect the resistance of the spark plug, the gap is only the color that changes to brownish white (normal). The best water media uses radiator coolant cooling water because it has a smaller heat transfer rate than ground water, mineral water because it has an antifreeze additive which makes the boiling point higher and the freezing point lower and anti-corrosion agent. Keywords: groundwater, mineral water, spark plugs, coolant, radiator, rate convection, heat transfer]]>
