The Stihl 400 concrete saw relies on a two-stroke gasoline engine to rotate a diamond or composite resin cutting wheel. The engine requires exactly the exact same type of maintenance as a lawnmower engine. The cutting wheel, which can fray, crack or break when used incorrectly, requires specific attention and proper fitting in accordance with the material you are cutting. The V-belt that drives the wheel has a automatic tensioner, however, the belt also requires periodic servicing.
Starting Procedure
If you can not start the engine, it may be because you are not using the right process, which is a little complex. You must first set the control lever on the cover of the casing to the start position, which involves forcing from the throttle trigger and activate interlock at the exact same moment. When the lever locks in position, place the choke to the cold start position — when the engine is cold — and thrust in the decompression valve, which is next to the onslaught. Pull the starter cord to get the engine running, then place the choke to the hot place. Do not forget to fill out the tank with gasoline and oil at a 50:1 ratio.
Poor Engine Performance
If you can not start the engine, the fuel may be contaminated if the saw has been in storage, and you should change it. You should also clean the air filter from knocking off dirt or blowing it with compressed air. If starting remains difficult, use a toothbrush to clean the spark arrestor — located behind the muffler — and then change the spark plug and fuel filter, which is located in the gas cylinder. If the engine still will not start or runs poorly, adjust the carburetor idle and low-speed screws to regulate the fuel/air mixture in the combustion chamber. If none of this works, you may need to remove the carburetor and clean it.
Cutting Wheel Issues
The TS400 requires two types of cutting wheels, and while they are usually interchangeable, you need a particular wheel for certain substances. You always need to use a mixture resin wheel when cutting metal, but a diamond wheel would be the better option for cutting clay or green concrete. Discard your diamond wheel if the teeth eventually become undercut, meaning the area metal under the diamond teeth becomes badly worn. An undercut blade can shatter, causing fatal or serious injury. If deposits collect on the teeth of your diamond blade when cutting dense substances, such as granite, they influence the blade’s cutting electricity. Eliminate them by cutting into a synthetic substance, such as sandstone.
Tensioning that the V-Belt
The V-belt connects the engine to the cutting wheel and must be properly tensioned to your saw to do optimally. To do it, you must adjust the tensioning bolt, located on the armature between the wheel and the engine. First loosen the 3 hexagonal securing the wheel cap to the armature and make certain the arrow on the tensioning bolt points to “0” Expand the bolt clockwise in an eighth of a turn — but no farther; a spring participates inside the armature and mechanically tensions the belt. You may need to repeat this process periodically to keep the proper tension on the belt.