YES.
go kart additives?? fuel or crankcase??
The 4 stroke Honda outboard is a 4 cycle engine using crankcase oil for lubrication, no fuel / oil mix is required.
In a two-stroke reed valve engine the reed valve is used to seal the fuel air mixture in the crankcase.
Crankcase compression refers to the pressure build-up within the crankcase of an engine, typically a two-stroke engine. It occurs when the piston moves downward during the intake stroke, compressing the air-fuel mixture in the crankcase before it is transferred to the combustion chamber. This compression is essential for efficient engine operation, as it helps in the timely delivery of the air-fuel mixture for combustion. Excessive crankcase compression can lead to operational issues, such as poor performance or engine damage.
Because of the way 2 stroke engines work. On a 4 stroke engine there are intake and exhaust valves in the head, and the crankcase is full of oil. On the intake stroke, the intake valve opens and the fuel-air mixture is sucked down into the cylinder. On a 2 stroke engine they put the fuel-air mixture into the crankcase. On the piston's down stroke, the bottom of the piston compresses the mixture. When the piston goes down far enough to open the inlet, the fuel-air mixture is squirted into the cylinder. If they put motor oil in the crankcase, you'd wind up squirting liquid oil into the cylinder. When the engine tried to "compress" the liquid oil, the incompressible liquid oil would break something.
Correct. A 4 stroke engine has oil contained within the crankcase that is pumped around to all rotating parts. Because the 2 stroke takes its fuel into the crankcase on route to the cylinder, lubrication is added to the fuel to keep the crank lubed. This is the main reason 2 stroke engines are less popular today as the lube oil within the fuel gets burnt. Emission regulations mean it gets tougher to keep the exhaust gases clean enough.
B: from the crankcase to the top of the combustion chamber. good luck on test :->
The function of the crosshead is that it absorbs the transverse thrust of the engine. The isolation of the crankcase allows lower cost residual fuels to be burnt without the fear of any fuel contamination of the lubricating oil of the crankcase.
Reed valves are typically found in two-stroke engines, often located between the intake manifold and the crankcase. They function as one-way valves, allowing the air-fuel mixture to enter the crankcase during the intake stroke while preventing backflow during the compression stroke. In some designs, they are mounted directly on the cylinder or the intake port. Their placement helps optimize engine performance and efficiency by ensuring proper air-fuel flow.
Worse case scenario. Float needle stuck in the carb with piston on the intake stroke. Rings may have washed out allowing fuel to pass into the crankcase. You didn't state how much gas though. Your yz uses the oil in the gas to lubricate the crankcase so a little is normal.
The reeds in a 2 stroke engine perform the same task as intake valves in a 4 stroke engine. The reeds are mounted to a flat plate, or a cage, positioned behind the carburetor(s). On the intake / compression stroke, the reeds are pulled open, exposing the holes milled into the plate, or cage, allowing the fuel charge to be pulled into the engine crankcase from the carburetor. During the power, or exhaust stroke, as the piston moves down the cylinder, the reed valves are forced back against the plate / cage, preventing the fuel charge from being forced back out of the crankcase. This fuel charge is then forced around the crankshaft, (lubricating the rods and bearings), and into intake ports, which are milled into the side of the cylinder wall. As the piston travels back up the cylinder, the intake port is closed off, the exhaust from the previous stroke is expelled, and a fresh fuel charge is drawn into the crankcase via the reed valves. This cycle is repeated over and over, amazing these engines are so durable.
Possible causes of fuel in crankcase are: Leaking injector at shutdown, flooding of the engine due to hard starting, defective fuel pressure regulator. A fuel pressure check for drop of fuel pressure at shut down will verify if an injector is leaking. Get this fixed ASAP, and stop driving the car until you do. Fuel in the crankcase will cause severe engine wear and destroy this engine. Change the oil and filter if you have to drive it anywhere for repair.