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All Journal Teknobiz : Jurnal Ilmiah Program Studi Magister Teknik Mesin International Journal Multidisciplinary Science
Sarwuna, Sefnath J Etwan
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Humanities Automotive Engineering Education Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Social Sciences

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Study of Pertamax and Pertamax Turbo Comparison on the Performance of 135CC 2-Stroke Motorcycles Sarwuna, Sefnath J Etwan; Willem Marthinus Eric Wattimena; Ekinov Limbong
Teknobiz : Jurnal Ilmiah Program Studi Magister Teknik Mesin Vol. 16 No. 1 (2026): Teknobiz
Publisher : Magister Teknik Mesin Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/6az5hq87

Abstract

Advances in vehicle technology and issues related to fossil fuel reserves have prompted Pertamina, as a fuel producer, to produce environmentally friendly, economical, and fuel-efficient fuels that also maximize engine performance. There are several types of motor fuels, including premium, pertalite, pertamax, and pertamax turbo. Each type has different specifications and octane number. The higher the octane number of the fuel used in a vehicle, the better the engine performance, while also reducing carbon deposits in the combustion chamber and producing emissions that are not harmful to the environment. Therefore, this study examines the effect of using Pertamax and Pertamax Turbo fuels on the torque and power of a 135cc RX-King motorcycle. This research is experimental in nature, using a Power Dyno testing device. The motorcycle is placed on the Power Dyno chassis and connected to a computer device, after which the torque and power values at certain revolutions are displayed on the monitor screen. The results of the study show that Pertamax fuel produces a maximum torque value of 9.00 Nm at 7116 RPM and power of 9.17 HP at 8181 RPM, while Pertamax Turbo fuel produces a maximum torque value of 9.26 Nm at 7250 RPM and power of 10.71 HP at 8181 RPM. This shows an increase in the performance of the Yamaha RX-King 135 engine when using Pertamax Turbo, which has a higher octane number than Pertamax.
Micro Hydropower Potential Assessment for Sustainable Tourism Electrification: A Case Study of Taeno Waterfall, Ambon Lilipaly, Eka Rahmat Mahayani Anthonio Putera; Wattimena, Sefnath J; Sarwuna, Sefnath J Etwan; Tupamahu, Cendy S E; Nara, Obednego Dominggus; Latumaerissa, Hendrik Simon; Aprilyanto Khouw; Rumalatu, Gilbert A; Hatuwe, Azmain N
International Journal Multidisciplinary Science Vol. 5 No. 1 (2026): February: International Journal Multidisciplinary Science
Publisher : Asosiasi Dosen Muda Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56127/ijml.v5i1.2637

Abstract

This study evaluates the technical and economic feasibility of micro hydropower development at Taeno Waterfall, Ambon, Indonesia, to support sustainable tourism electrification. Hydrological assessment was conducted using 10-year rainfall data (2014–2023) combined with the National Rural Electric Cooperative Association (NRECA) method to estimate streamflow in the absence of long-term discharge measurements. The results indicate an average annual rainfall of approximately 3619.92 mm and an estimated average discharge of 0.70 m³/s. Flow duration curve analysis produced dependable flows of Q50 = 0.63 m³/s, Q80 = 0.35 m³/s, and Q90 = 0.28 m³/s, confirming adequate water availability for year-round micro hydropower operation. Hydraulic analysis showed a gross head of 24 m with a net head of 22.44 m after accounting for friction and minor losses. Using a design discharge of 0.35 m³/s and an overall efficiency of 75%, the estimated electrical power output is approximately 58 kW, classified as micro hydropower. A crossflow turbine was identified as the most suitable technology due to its compatibility with medium-head and moderate-flow conditions, operational flexibility, and cost effectiveness. Estimated electricity demand for tourism facilities is approximately 30 kW peak load with annual consumption of 66 MWh, indicating that the proposed system can fully meet demand with surplus energy for future expansion. Economic analysis using the Indonesian electricity tariff of 0.086 USD/kWh yields an annual benefit of approximately 19,278 USD and a payback period of about 12 years. The findings demonstrate that Taeno Waterfall possesses strong potential for sustainable renewable energy implementation to support tourism development and local energy resilience.
Co-Authors Aprilyanto Khouw Ekinov Limbong Hatuwe, Azmain N Latumaerissa, Hendrik Simon Lilipaly, Eka Rahmat Mahayani Anthonio Putera Nara, Obednego Dominggus Rumalatu, Gilbert A Tupamahu, Cendy S E Wattimena, Sefnath J Willem Marthinus Eric Wattimena