Regardless of the class of the chainsaw and its operational characteristics, the design of removable saw sets is almost identical. The saw device kit includes a guide bar made of a special alloy and a chain, which is activated by the gear ring of the drive mechanism. To extend the life of the saw chain, timely replacement of the sprocket on the chainsaw is important.
The feasibility of timely replacement of worn parts of the drive chain
The design of its crown determines such an important parameter as the choice of chain by step.
- Installing a new part on a worn sprocket reduces its smoothness, accelerates wear, and initiates the risks of breakage and the creation of a traumatic situation.
- There is also an increase in operational loads on the engine and the elements of the kinematics of the tool.
- A similar process takes place when old extended chains are installed on the tire, the diameter of which is adjusted to the size of the tire by removing part of the links.
Experts also do not recommend arbitrarily changing the size of the stars. An experiment can adversely affect the engine resource and the kinematics of the instrument as a whole.
Safety of sawing operations of various degrees of complexity is ensured by the effective operation of the emergency stop brake and devices that block the expansion of the chain ends in case of an accidental break. In any case. the most reliable prevention of contingencies, maintaining the chainsaw in good condition.
A way to extend the leading sprocket resource
In practice, for uniform wear of the crown of the sprocket, a set of several chains of the same type is used, which alternately change as the cutting edges of the saw links become blunt. However, sooner or later, the user is faced with the need to replace a worn part.
Criteria for choosing a repair kit yourself
The desire of the owner to equip the headset with a saw chain with another step, leads to the need to change the asterisk to a part with a crown of the corresponding profile. This requirement applies to the entire range of European and Chinese chainsaws.
The operational reliability of a European-assembled saw, when operating in difficult conditions of increased loads, can significantly deteriorate if, instead of the original part, a Chinese asterisk is used.
Video: How to Remove an Asterisk From a Parma Saw 3
Structural problems of different models
The problem is complicated by the design of branded chainsaws, which provides for the replacement of a worn drive only after the complete dismantling of the clutch mechanism and other components. In another embodiment, in order to remove the sprocket from the chainsaw, you must have a special key.
A design feature of a significant part of chainsaw imports is the placement of an asterisk on the clutch mechanism.
- With significant wear of the teeth, the drum is to be replaced, which is a single unit with the drive.
- The more progressive design of the drive sprocket allows you to restore the performance of the part by replacing the crown.
In the list of factory kits attached to the saws, such a tool is extremely rare. The problem is solved by replacing the parts that have exhausted the resource in the service workshop or by making the necessary fixtures at home.
The lack of prerequisites for the restoration of a worn star
The leading sprocket for a chainsaw of any power category is made of special steel, processed by a special technology, so repairing a part by welding by arc welding and subsequent milling is not possible.
The price of the part itself is several times lower than the cost of replacing it in service structures.
- The benefits of self-repairing a drive unit at a lower cost and time.
- If you have the appropriate tool, you can manage the work for a fairly short time interval.
Alternative solutions
The sequence of working moments is identical for almost all known models in the domestic market of chainsaw equipment. Experts advise using a branded part for replacement.
If we are talking about the modernization of this node, the feasibility of such a change should be clarified by consultation with an experienced specialist.
The best option is to buy a repair kit, which also includes a replacement bearing. In addition to the key, you may need an individual for each model puller of the clutch drum, a metal or plastic stopper to fix the piston in a predetermined position.
Algorithm for self-changing drum clutch with sprocket
Leading sprocket replacement technology provides for the implementation of the entire amount of work in a given sequence:
- dismantling the headset and air filter;
- installation of a piston retainer in the spark plug hole;
- the clutch and the gear drive made at the same time as the drum are removed by means of a puller; the sprocket can only be unscrewed clockwise.
If there is a lot of wear on the separator, breakdown of the springs of the centrifugal mechanism and cams, it is recommended to replace the entire kit.
If the condition of the removed parts is not in doubt, the whole mechanism is assembled in the reverse order. For reliable fixation of the clutch on the crankshaft, it is enough to unscrew the piston stopper, pull out the cord of the standard starter and return it to its original position.
It should be cautioned by amateur craftsmen from simplifying the requirements of repair technology and saving money on installing relatively cheap Chinese components.
The quality of the work done is guaranteed by attention, accuracy, compliance with the sequence of all dismantling and assembly operations.