Models equipped with two-stroke engines are no longer considered an endangered species. Among them, models introduced before the early 1980s were equipped with numerous 2-stroke engines, ranging from large to small displacements. Although these 2-stroke models are still known for their enthusiastic fans, there is a procedure that must never be mistaken when reviving an immobilized engine. Do not start the engine out of the blue. This is the first thing you should know. Here, let us reconfirm the setup procedure for starting a 2-stroke engine.
Remove spark plugs and a few empty kicks.
Before starting the engine, is there spark flying at the plugs? Remove the spark plug, press it against the head, and give it a kick. There was a powerful spark, but there was something strange going on.
Mix oil with fuel at about 25 to 1.
During maintenance, it is better to proceed with a maintenance drip tank, commonly known as a maintenance drip tank, rather than fuel in the tank. For two-stroke engines, make the fuel mixture at a ratio of 25 to 1.
For the 2-stroke oil, I used Super Zoil 2-stroke oil. The main attraction of this old-fashioned red oil is that it is a modern high-performance oil. Prepare the fuel mixture before starting the engine.
If you remove the carburetor and give it a few empty kicks, you'll see ......
After removing the spark plugs and stepping on a few empty kicks, engine oil gushed out of the plug holes like a geyser. At this stage, I noticed that engine oil was falling from the oil tank into the crank chamber. So I took off the cover and removed the main body of the carburetor, and engine oil flowed out of the intake port. If we had attempted to start the engine without noticing this anomaly, we would have experienced a water hammer phenomenon, which would have resulted in serious engine trouble.
When you get to this point, try to start the engine.
The engine waist was disassembled in the order of cylinder head and cylinder, and the engine oil accumulated in the crank chamber was drained out with a syringe. After that, the crank chamber was cleaned with mixed fuel, and the oil was extracted again with a syringe to restore the engine waist up. Then, the check valve, which was thought to be the cause of the trouble, was cleaned, and the oil line + check valve function was thoroughly checked. After that, we set about starting the engine, which took only a few kicks to start. It sent a shiver down my spine to think that I had been working on this project without thinking.
POINT
Point 1 - Do not suddenly refuel and start the engine.
Point 2 - Be careful of oil dropping into the primary compression chamber = crank chamber
Point 3 - Know the current condition by activating the empty kick.
In the case of a 2-stroke engine with a separate oil feed = oil pump, a check valve is installed in the middle of the oil line leading from the oil pump to the intake manifold and cylinders to prevent engine oil from falling naturally. In the case of this vehicle, we felt something unusual during an empty kick before starting the engine. Does the crank operate normally before starting the engine? Does the spark come from the spark plug? Remove the plug, press the threaded part against the cylinder head, and step on the empty kick several times to see if it cranks normally Does a spark come out? During this process, engine oil came out of the plug hole with a squish-squish sound like a geyser.
So, before starting the engine, we decided to remove the carburetor and check and inspect the oil injection nozzle. We found engine oil accumulating in the intake port as if dammed up by the closed rotary disc valve.
If the cutout in the rotary disc valve is inserted into the intake port, the engine oil will naturally fall into the primary compression chamber (crank chamber) of the crankcase. Specifically, if the engine oil in the oil tank is low even though the engine has not been running much, "Is the amount of oil dropping? Be careful in such a case! If you try to start the engine without noticing such a drop in oil, the engine oil that has fallen into the primary compression chamber and accumulated will rise from the scavenging port to the combustion chamber by cranking, and in the next instant, water hammer phenomenon will occur, and the head gasket will blow through even if it is unfortunate. At worst, it can result in piston destruction and bent connecting rods. If a two-stroke engine has experienced a water hammer phenomenon in the past, it must have had some symptoms, so check and inspect the check valve in the oil line when you notice it.
Also, a faulty fuel cock or carburetor float valve can cause overflow, causing fuel to flow down into the engine rather than out, and still cause the same problem. If owners of 2-stroke engine models notice anything unusual, they must inspect each component and replace parts as necessary.
With that in mind, when starting the engine after a long time, let's remove the spark plugs and make sure that the engine is cranking smoothly. If you notice that engine oil or fuel has dropped into the primary compression chamber = crank chamber, you have to drain all the liquid in the crank chamber. In this case, disassembly of the engine waist is necessary, and the liquid is drained out with a syringe + tube. After that, the inside must be cleaned with mixed fuel, and the gas mixture must be extracted again with a syringe, from which restoration maintenance must begin.
Be careful not to try to start the engine halfway with engine oil or cleaning fuel mixture remaining, as the aforementioned water hammer phenomenon will cause meaning less damage to the engine.
