Piston port is the simplest of the designs and the most common in small two-stroke engines. All functions are controlled solely by the piston covering and uncovering the ports as it moves up and down in the cylinder. In the 1970s, Yamaha worked out some basic principles for this system. They found … See more A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in … See more Crankcase-compression two-stroke engines, such as common small gasoline-powered engines, are lubricated by a petroil mixture in a total-loss system. Oil is mixed in with their petrol fuel beforehand, in a fuel-to-oil ratio of around 32:1. This oil then forms … See more Although the principles remain the same, the mechanical details of various two-stroke engines differ depending on the type. The design types vary according to the method of … See more Direct injection has considerable advantages in two-stroke engines. In carburetted two-strokes, a major problem is a portion of the … See more The first commercial two-stroke engine involving cylinder compression is attributed to Scottish engineer Dugald Clerk, who patented his design in 1881. However, unlike most later … See more Two-stroke gasoline engines are preferred when mechanical simplicity, light weight, and high power-to-weight ratio are design priorities. By mixing … See more Many modern two-stroke engines employ a power-valve system. The valves are normally in or around the exhaust ports. They work in one of two ways; either they alter the exhaust … See more WebPorting refers to the process of enlarging and shaping the intake, exhaust, and transfer ports around the cylinder of your 2-stroke engine. As a rule, when porting and polishing your 2-stroke engine cylinder, you’re attempting to match the size of the intake manifold and intake port, as well as the exhaust manifold and exhaust port. The ...
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WebINTAKE PORT. For a piston port intake there needs to be around 120 degrees of port open duration for a peak rpm around 6000. Higher rpm needs more port duration. The Maico motocross bikes had around a 160 degree duration. For a reed valve intake there needs to be holes in the piston that allows passage of fuel mixture from the carb to the ... WebJun 29, 2024 · Stothers says that the placement and actual number of vertical ports is determined both by piston diameter as well as real estate limitations driven by intake … holding a cigarette drawing
converting piston port to reeds. how to? - ThumperTalk
WebNov 8, 2024 · Piston port 2 stroke tuning manual Many people talk about a port area as a target value and indirect refers to a header area with an area factor for the port. That approach is a completely waist since port area don’t give any information about port shape. Time area is still the standard unit for 2-stroke ports since at least 1971. WebOct 28, 2011 · Yamaguy55. Posted July 4, 2011. Easy answer is to compare DT1 Yamahas to DT2/3s, that's when they cut over to reeds. Yamaha changed the porting substantially, had a small "window" from the intake go up and become a transfer, which of course would work because of the reeds. They also had holes in some pistons. WebJun 17, 2024 · Engine: 249cc Villiers 2T 3-stroke twin, piston port, 50mm x 63.5mm bore and stroke, 8.2:1 compression, 15hp @ 5,500rpm Carburetion: 22mm Villiers S22/2 Transmission: 4-speed, right foot shift, chain final drive Electrics: 6v, 120 watt generator holding achilles syd fest