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Archive for March, 2010
Just as the main jet controls the flow of fuel and bulk motor oil when the throttle is open, the needle and needle jet take over when the throttle is anywhere from one-eighth to three-quarters open. Since your engine is operating in this range the majority of the time, this carb circuit generally gets the most use. When making adjustments, the needle itself rarely needs any tuning.
As the throttle opens, the needle is pulled up. This allows an increased flow of fuel and oil. If need be, you can make minor adjustments using the clip that is on the needle; raising the clip will make the mixture leaner, and vice-versa. Tomorrow we will go over the final circuit of the carburetor, the pilot jet and pilot screw.
Yesterday we introduced the purpose of jetting a carb and quickly overviewed the three main circuits. Depending on whether you have a four or two-stroke engine, the carburetor adjusts the ratio of fuel to air or of fuel and Evinrude XD100 oil and air, respectively. Today we will be examining the main jet more closely and seeing the impact that it has on your vehicle.
When the throttle is more than three-quarters of the way open, the main jet comes into play. At this point, the needle is high enough that the main jet is now controlling the flow of fuel. The main jet is categorized by a number that indicates the size of its hole; the bigger the number, the larger the hole. A higher number will allow more fuel to get through the system, resulting in a richer fuel to oil ratio.
Changing your outboard motor oil and doing other routine maintenance is important, but if you want to get the most out of your vehicle, you are going to have to do more than just routine maintenance. One of the most important components of your engine, with regards to the smoothness and efficiency of your ride, is the carburetor. The carb controls the ratio of fuel and air mixture that your engine uses. Finding the proper balance of these two variables will give your machine optimal power and reduce its emissions. The next few days we will be going over how to jet the carburetor on your ATV.
Before we begin, it is important to understand that there are three main carb circuits, each of which controls a range of throttle positions. The main jet is used when the throttle is three-quarters to fully open. When the throttle is open one-eighth to three-quarters, the needle jet is used, and for the final positions, the pilot jet and screw come into play. Tomorrow we will go into more detail with these carb circuits and begin discussing how to jet the carb.
Humans are creatures of habit, and this is particularly apparent when it comes to our purchasing decisions. For most of us, when we find a product we like, we tend to stick with it. As an avid boat enthusiast, I developed my canon of essential products years ago and have rarely deviated from those lines of products.
My son recently purchased his own boat however, and he has started using different oils and lubricants. He told me that there have been amazing advances in technology over the past few years and suggested that I tryout Evinrude XD 100. I’m not sure if it was the oil or just the placebo effect, but from the first time I used it, I recognized a palpable difference in my boat’s performance; it accelerated smoother and ran quieter. I think that my loyalties have shifted.
It will still be several weeks until the weather is warm enough to pull my boat out of storage, but I am already planning my summer trips. Each year every member of my family gets to choose a nearby body of water where we go stay for a long three-day weekend. My wife and kids always rotate the destinations they select, but for the last ten years, my choice has always been Lake Chelan.
Although the lake has become decidedly more crowded in recent years, there are still areas you can retreat to where there are no other boats in sight. After drawing straws, it was determined that I would get to pick the first spot we went. I am already anticipating the trip and have even changed the outboard motor oil and done the rest of my preseason checks.
Spring officially started last weekend, and while for some people the season is a time for blooming flowers and love, spring only means one thing to me: ATV season. Like most ATVers, I love the mud, and springs in the Pacific Northwest give us an ample supply. I’ve been tied up with some chores and duties around the homestead, but I think that I will finally have a chance to take my ATV out this weekend.
In the next few days, I hope to be able to do all of my preseason ATV checks. If you’ve never done this before, it is fairly simple. You’ll want to thoroughly inspect your vehicle for any cracked or loose fittings, and be sure to top off the Yamalube 2w oil and other essential fluids.
In addition to viscosity, flash point and pour point, there are a few other specifications that will help you decide whether Evinrude XD100, Yamalube or some other oil is right for you. When oil reacts with sulfuric acid and burned, there is always some amount of solid residue. The amount of this solid material that is leftover is referred to as the percentage of sulfated ash.
In oils, zinc is used to prevent damage that would be incurred when two metal parts come in contact with one another. The amount of zinc that is used is reported as the percentage of zinc, which is typically about 0.1%. While these specs will give you a good idea of how the oil will perform, you should also consider the base stock and additives that the manufacturer uses in production.
Now that we’ve covered the basics of oil viscosity, it is time to look at some of the other main specifications for your outboard motor oil. The flash point represents the temperature that the oil will be ignited at if exposed to an open flame. At this temperature, the oil will emit flammable vapors. Generally, the higher the flash point, the better the quality of the oil.
Like all liquids, oil can be chilled to a temperature where it is stagnate. The pour point is five degrees above this point and is particularly important for vehicles that are used in the winter. As you can probably ascertain, the lower the pour point is, the better. The flash point and the pour point represent the two extreme temperature limits of the oil, and aside from the viscosity, are the most important specs to consider.
Yesterday we provided a brief overview viscosity and discussed why you it is important to consider it when purchasing Evinrude XD100, or any other oil, for your vehicle. Over the years, oil technology has advanced greatly, and one of the most important innovations is multi-viscosity oil. In order to allow the oil to maintain a higher viscosity in high temperatures, manufacturers add polymers to light base oils.
This means that the oil now has a range of viscosities. 20W-50, for example, will typically have a viscosity of 20, but it will not exceed 50 in excessive heat. When choosing multi-viscosity oils, you want the range to be as small as possible. As the range grows, more polymers need to be added to the oil, which jeopardizes the quality of the product.
The viscosity is the most important spec to consider when purchasing outboard motor oil. Essentially, the viscosity is a measurement of how well the oil flows. As a rule of thumb, thick oils have a high viscosity, and vice-versa. If your oil’s viscosity is too low, it will lose strength at high temperatures, while if it is too high, the oil will not be able to pump to all of the necessary components of the engine.
The weight of the oil corresponds to the oil’s viscosity. Higher weights indicate greater viscosity in the oil. If there is a “W” next to the number, this signifies that the oil has been tested in cold temperatures and is approved for winter use. Tomorrow we will wrap up our discussion on viscosity and highlight multi-viscosity oils.