The McCulloch 160s is a discontinued model of chainsaw sold between 1983 and 1995. The 32.8cc motor with this saw comes equipped with either a Walbro or Zama brand carburetor. These carburetors do the identical function, but there are a number of minor mechanical differences between those models. Both carburetors have been diaphragm-type carburetors which use a flexible barrier that prevents fuel from leaking when you flip the spool on its side.
Walbro Carb Specifications
The first carburetor installed on the McCulloch 160 is the Walbro MDC-16 carburetor. This carburetor consists of 32 components, but only 25 of them are available from the major and minor repair kits. The small kit comprises replacement parts for regions of the carburetor that commonly need replacement such as the displays over the port, the diaphragm at the gas pump, gaskets along with the needles that control the flow of fuel through the carburetor. The functioning of the MDC-16 is flexible using two screws attached to needles that adjust the flow of air and fuel through the carburetor at slow rate and higher speed.
Zama Carb Specifications
The Zama M1-M7 carburetor is the replacement model for the Walbro carburetor. It consists of 28 components but performs the very same functions as the Walbro model. The M1-M7 carburetor includes 16 replaceable components which can be found in three kits designated the repair, gasket and needle kits. Contrary to the repair kits for the Walbro carburetor, these kits have several common pieces.
Identifying the Carb
The replacement components for the Zama and Walbro models are not interchangeable. You can identify if your McCulloch 160 includes a Zama or Walbro by the model number on the body of the carburetor. On Zama carburetors the model number is usually found beside the steel barbs that attach into the gas lines.
Adjusting the Carburetor
Turning the high speed screw clockwise increases the flow of air through the carburetor at a given throttle setting, resulting in a leaner mixture. Turning the high speed screw at the other direction increases the amount of oil and fuel, resulting in a richer mixture. Fixing the idle screw clockwise increases the rate of the motor while it is idling and turning it the opposite direction decreases it. Slowly turn every screw clockwise and counter-clockwise using the motor running and notice the difference in motor performance as the fuel mixture becomes leaner or richer. Since the mixture becomes too rich or too lean the motor will start to get rid of power. The perfect setting for both screws is midway between the two points in which turning the screw starts to cause the motor to slow down. Fixing the idle screw simplifies the alteration process.
Safe Adjustment Approaches
Fixing the high speed screw to conduct lean decreases the amount of lubricating oil delivered to the piston. Operating your saw at high rate using a lean mixture for at least a few seconds can result in critical damage to your saw’s motor. Always keep the saw on flat Landscaping companies Redding with the blade away from yourself, obstructions and bystanders when you are correcting the saw with the motor running.
