Handheld concrete saws, chop saws or what STIHL calls the STIHL Cutquik® have been used for many years in a variety of applications in the construction industry. These machines are subjected to some very harsh running conditions, and the expectation is that the machine will always run. In the construction business, time is money and production is critical to the success of the project.
In an effort to increase durability and reduce maintenance costs, STIHL has introduced the X2 air filtration system. All our current machines utilize this filtrating system, and it is proving to be a great success. With this system, the air filter may not need to be cleaned for up to one year; now that’s quite a change from yesteryear when weekly or, in some cases, daily cleaning was required.
So, before you all put this article down and say this guy is crazy, hear me out for a moment. The X2 air filtration system is more than an air filter jammed into an air box to stop the dust. It actually is a complete system where all the air entering the engine goes through a 3-step cleaning process before it does get to the carburetor.
The incoming combustion air passes through a cyclone cleaning system. Three intake cyclones cause the air to rotate at a high speed. The rotation of the air causes the heavier dirt particles to move to the outside of the air stream inside the cyclone. Attached to the cyclone is a low pressure or vacuum tube from the engine flywheel. This low pressure ensures that all the dust and dirt separated in the cyclone is removed from the cyclone and ejected back into the atmosphere. This pre-cleaning system actually removes the largest percentage of dirt from the air stream.
Includes a pleated paper main filter. An air filter is made up of specially designed paper. This material must withstand the temperature at which the machine operates and withstand the high volume of small dirt particles not removed by the pre-cleaner. This filter element is designed to become covered with dust and debris, and this is a good thing. When we look at a filter we say it’s dirty; however, that dirt is actually part of the filtering system. Now you say hang on, the dirty filter is part of the filter system - that’s right, it is. Think of the filter as fibers laid in a pattern to form a screen like mesh; kind of like a screen door. The air passes through the holes in the mesh.
Now understand these “holes” are very small; so small, in fact, you cannot see them with your naked eye. As dust and dirt builds up on the filter, these “holes” become smaller and help keep the very fine dust out of the engine. This process of building up the layer of dust is referred to as “filter cake”. That dirt and dust you see on the filter is actually your friend in that it helps keep your engine clean. So how come the filter does not become too dirty? Good question. The design of the filter is such that, as the machine operates, the pleated paper vibrates and this vibration will knock off the excess material and it will lie in the bottom of the filter cover. It is not uncommon to service a machine after one year of running with 3-5 cms of dust in the bottom of the filter cover. This is good news because this dirt did not enter your engine.
What happens when you clean the filter? A couple of things. One, if you use an air hose to clean filters, you force debris through the pleated paper, opening up those “holes”, allowing larger pieces of dust and debris through the filter. Secondly, you can damage the seal and distort the filter and, as I said earlier, that “filter cake” increases the effectiveness of the filter so why remove it. We employ a carburetion system that automatically adjusts the air-fuel ratio depending on how freely air moves through the air filter, ensuring the machine will not suffer loss of fuel economy because of an air filter becoming dirtier. This is referred to as IntelliCarb™.
STEP 3Is an auxiliary air filter. This is a final filter before the air enters the engine to remove any debris passing both the pre-cleaner and the main pleated paper filter. The second function of this filter is to ensure that the main filter does not become damp from “spit back” from the engine.
So the question is; to service or not to service? STIHL recommends that you do not service or inspect the air filter until the machine begins to lose power. When it does lose power, change both the pleated paper main filter and the auxiliary filter. Under no circumstances should you clean or “blow out your filters”. Servicing your STIHL Cutquik® this way will save you both time and money.