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Four-StrokeAsk KevinThe Exhaust StrokeLots of nonintuitive stuff happening.By Kevin CameronJanuary 10, 2024Ask KevinThe Power StrokeFuel energy turns into mechanical energy.By Kevin CameronJanuary 4, 2024Ask KevinThe Compression StrokeStep two in turning fuel and air into heat and then into motion.By Kevin CameronDecember 21, 2023Ask KevinThe Intake StrokeThe foundation of everything that follows.By Kevin CameronDecember 12, 2023Ask KevinThe Four-Stroke and Its History ExplainedRise of the Otto Cycle heat engineBy Kevin CameronDecember 8, 2023Buyer's Guide2021 GasGas EX 250FA four-stroke machine for riders looking to conquer wooded trailsBy Cycle World StaffMarch 1, 2021Buyer's Guide2021 GasGas MC 250FA new addition to the 250 four-stroke motocross bike classBy Cycle World StaffFebruary 26, 2021Buyer's Guide2021 KTM 250 SX-FKTM’s 250 four-stroke has got it all.By StaffJanuary 20, 2021BikesCritical Parts Of Machines Fail If They Get Too HotKeeping things cool…By Kevin CameronOctober 3, 2019Bikes2020 KTM SX-F And XC-F Models ReleasedLearn about KTM’s 2020 four-stroke motocross and cross-country bikesBy Andrew OldarMay 1, 2019BikesExploring Two-Stroke Motorcycle Engine DesignA narrative of two-stroke scavenging, part 2By Kevin CameronJanuary 16, 2019BikesLightness And Simplicity Are The Basic Appeals Of A Two-Stroke Motorcycle EngineA narrative of two-stroke scavenging, part 1By Kevin CameronJanuary 11, 2019BikesHow Fuel Efficiency And Fast Combustion Are Related“Fast combustion sent more power to the pistons and less into the cooling and exhaust systems”By Kevin CameronDecember 26, 2018BikesFree Supercharging For Four-Stroke Piston EnginesWhere did I get that figure of 500 feet per second as intake velocity?By Kevin CameronNovember 29, 2018BikesWhat Is The Four-Stroke Piston-Engine Cycle?How intake, compression, power, and exhaust will get us home for the holidaysBy Kevin CameronOctober 15, 2018Bikes2019 Husqvarna FC And TC Models First LookFirst look at Husqvarna’s four-stroke and two-stroke motocross bikesBy Andrew OldarMay 30, 2018BikesHow Do Motorcycle Exhaust Pipes Work?Cycle World Technical Editor Kevin Cameron answers your engineering and mechanical questionsBy Kevin CameronApril 18, 2018Chase-TruckPlaybike vs. Racebike: A Rebuttal–By Allan GirdlerBy Allan GirdlerApril 21, 2011Chase-TruckFour-Stroke Dirtbikes: The New Reality—By Kevin CameronBy Kevin CameronApril 6, 2011
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