The carburetor is one of the most vital components of any two-stroke engine, as it works to blend the air, fuel, and outboard motor oil so that they can be utilized in the stroke cycle. For many owners of two-stroke engines, however, carburetor maintenance and mechanical issues are a headache. The next few days we will go over the basics for making routine adjustments to the carburetor.
Always start by adjusting the idle, which controls the RPMs that the engine runs at. Set the idle speed to the proper RPM level by adjusting the idle screw. Next, turn the idle mixture screw so that the engine runs smoothly, with the optimal speed and response. Once this is done, make any final adjustments to the idle screw that may be needed. Tomorrow we will continue reviewing carburetor adjustments.
Aside from your house or car, a boat is probably one of the biggest purchases that you will ever make. With that in mind, it is important to do some research before dropping thousands on a watercraft. One of the most important things to consider is whether you want an inboard or outboard motor.
Outboard boats tend to be less expensive and our good for fishing and other leisurely water activities, while an inboard is a near necessity for extreme water sports. In this down economy, many people are considering buying a used boat and saving some money. If you are considering this route, put the boat through a strict vetting before finalizing your purchase. Aside from inspecting the hull and outer surfaces, also examine the engine to ensure that the previous owner maintained the system with Evinrude XD 100 and other essential fluids.
Now that we have overviewed the inner workings of a two-stroke engine, the advantages should be ascertainable. The consolidation of the stroke cycle allows for a more rudimentary and lightweight design, which also produces more power. This combination makes two-stroke engines ideal for various handheld equipment and small vehicles. With these obvious advantages, some may be wondering why two-stroke engines aren’t used in cars and other large vehicles.
The main drawback to the two-stroke is its longevity; the fact that the outboard motor oil and gasoline are mixed means that there is less direct lubrication, and the system wears faster. Because of this necessity to mix the gas and oil, the engine burns more of these fluids than there four-stroke counterpart—which is a major drawback in a vehicle that experiences extended usage. Finally, there is also more pollution emitted from a two-stroke due to the nature of its compression cycle.
Yesterday we overviewed the main process that takes place in the cycle of a two-stroke engine. Now we are going to breakdown this process a little further to better understand what is occurring in this process. When the piston is working in its cycle, the crankshaft will give the piston momentum so that it can return to the spark plug for the compression stroke. During this process the piston compresses the mixture of Yamalube oil, fuel and air to create a vacuum, which in turn opens the reed valve and draws in more of this mixture from the carburetor.
Once the cycle is completed, the piston will fire again and repeat the process. The fact that there are two strokes—the compression and the combustion—is how the engine gets its name. Because the piston accomplishes so many tasks, the two-stroke engine so lightweight and versatile. Tomorrow we will review some of the major pros and cons of the two-stroke engine.
Yesterday we overviewed some of the basics differences between four and two-stroke motors. Today we will go over some of the mechanical operations of the engine. A two-stroke engine is essentially a simplified version of the four-stroke, and this means that the cycle is more economical and many of the operations are consolidated. As we said previously, one of the biggest differences is that the spark plug fires once every revolution, as opposed to every other revolution.
The design of a two-stroke engine is designated as a “cross flow” and starts with the firing of the spark plug. The fuel and Evinrude XD100 mixture is combined with air and compressed. When the spark plug fires, it ignites that concoction and drives the piston of the engine. Once the piston hits its down stroke, the exhaust port is covered and the pressure drives the exhaust gases out. After the piston bottoms out, the intake port is covered and the mixture rushes into the cylinder, allowing the remaining exhaust gases to escape and fresh fuel to enter.
There are three basic types of engines that are used in motor vehicles: gasoline; diesel and two-stroke. While the first two types are typically found in automobiles and other high-power vehicles, two-stroke engine are ideal for smaller crafts such as outboard motor boats, ATVs and snowmobiles. Gasoline and diesel engines use several of the same principles in their design and operation, but the two-stroke engine has some discernable differences:
~Two-stroke engines have no valves, which makes their construction more simple and lightweight
~Four-stroke engines fire every other cycle while two-strokes fire every revolution, giving them more power
~Since the outboard motor oil is mixed with the fuel, two-stroke engines will work in any orientation, which is important for handheld equipment
For over a century, the Evinrude name has been synonymous with quality in the outboard motor world. Originally founded by Ole Evinrude in Wisconsin, the company has vastly expanded and is now owned by Bombardier Recreational products, one of the premier motor vehicle producers. Bombardier is a leading manufacturer of ATVs, snowmobiles, and, of course, motorboats.
Today Evinrude is focused on producing top-of-the-line two-stork engines in their boats. J.D. Power and Associates even rated Evinrude as the “highest in customer satisfaction with two-stroke outboard engines in the US.” There is even a line of Evinrude outboard motor oil that is specifically designed for two-stroke engines, including Evinrude XD100.
The benchmark for two cycle oil is TC-W3 certification. Two stroke engines require users to mix the fuel with outboard motor oil to lubricate the various components. During this process oil is both burned, and unburned, creating various emissions and leakage concerns. The goal of TC-W3 is to ensure that the oil meets proper lubrication standards while still holding up to EPA regulations.
There are various tests the NMMA, the organization that manages TC-W3, employs to rate oil. Some of these tests include: liquidity, fluidity, viscosity, and standards for ring sticking and carbon build up. NMMA uses various motors and performs 100 hour tests to determine the specs for the oil. While there are no specifications for the oil formula, it must meet the minimum standard in the testing to be certified.
As you can probably ascertain from its name, Yamalube oil is a product of the Yamaha Company. Aside from their extensive line of motor vehicles, Yamaha’s selection of Yamalube products is one of their most lucrative endeavors. In order to reach the widest market possible, there are several varieties of Yamalube available that are specifically catered to certain vehicles.
The full synthetic blend is for high-performance use, such as racing and low-temperature snowmobiling. Semi-synthetic Yamalube oil, such as 10W-50 and 0W-30, is created from a proprietary blend of synthetic and mineral oils. Their mineral oil is produced from the highest quality base stocks and can be used in a wide range of small motor vehicles.
A recent study of outboard motors yielded evidence that quieter motors are also more fuel efficient as well as better for the environment. The test was run on a 1988 Evinrude outboard motor versus a 2008 Evinrude outboard motor. The results of the test were as follows:
~The 2008 motor was 38% more fuel efficient than the 20-year old version
~Based on Friday’s fuel prices at the dock, this equates to a savings of $16 per hour
The most startling difference between the two motors was when both were started, the 2008 hummed quietly as it warmed up, while the 1988 motor gargled and spewed smoke and fumes for several minutes. Although you can use the same Evinrude XD 100 on both engines, the recent advancements in engine technology is palpable.