First Sign of Trouble
Taking care of your chainsaw means making sure that it runs properly without any signs of trouble in regards to having a hard time of starting the engine. Particularly on cold starts which may require you to frequently tug on the pull string to get it running. Many find this sort of situation very annoying since it takes a substantial number of attempts to get the engine to start and very tiring as well. Where to start? Trouble with making evaluations on why your chainsaw has difficult in starting may mean that you have to find the root cause of the problem, which can be a combination of many things. To start off, you need to find out the basic principles on how two stroke engines work which contribute to how they run in regards to their setup. Basically, two stroke engines run on a very simple principle which involves the the perfect mixture of air and fuel into the carburetor that the engine solely depends up to run but it is not as simple as that. It should be fairly taken into consideration that the mixture of fuel and air should be just right as having a lean mixture (more air than fuel) can cause your engine to stutter and a substantial increase of temperature caused by too much oxygen will eventually overheat your engine.
Checking the Carburetor
On the other side, having a mean mixture (too much fuel than air) will result in too much exhaust fumes because of lack of adequate oxygen to efficiently burn the fuel, which also means that fuel is wasted resulting with a pungent smell of gasoline from the exhaust oh the engine. Two stroke engines are fairly easy to maintain as they are not so particular in the type of gasoline that you put into the tank, although you should be aware that using high octane fuels can damage your piston rings and the piston themselves since high octane fuels that are above the 96% octane rating do not offer the right amount of top lubrication for your pistons. Most of the time, you are obliged to mix 50 parts of gasoline with 1 part oil mixture to ensure that your piston rings are well lubricated during the combustion process. This is required on all two stroke engines to keep the internal combustion chamber in good running condition as it will reduce unwanted friction on the cylinder bore.
Since the carburetor is very important in maintaining your chainsaws pristine running condition, you should check whether or not something is causing it to run improperly. Taking it apart to check if there are particles that have managed to sneak inside the assembly which could cause the irregular flow of fuel and air. Taking out the components one by one and cleaning them off to ensure that nothing is blocking the passage ways and putting it back on the engine should solve most of the issues concerning hard starts. Be very keen on the way you put back the carburetor and make sure that you will not leave any bolt loose since having a breach in this point of the intake manifold would let too much air into the engine while it runs, causing unwanted overheating resulting in a lean mixture of fuel.
Pistons and Piston Rings
Another thing that you should look into is to find out if your pistons can still hold a good amount of compression to effectively drive the main crankshaft. This is particularly common for old engines and since engines do get worn out, it is good to see if the piston rings are still efficient in maintaining proper chamber pressure. To find out, there is a tool which is plugged into the spark plug socket which measures the chamber pressure as the piston is moving from top dead center to it’s idle position. If the gauge that measures the combustion chambers pressure falls below the acceptable level, you should take the top block apart and see if your piston and piston rings need replacement. Also measure the clearance of the cylinder bore in relation to the piston’s clearance to give you an idea if you need to get either a new piston or a new cylinder block or both. Frequently worn out pistons result from not having enough two stroke oil mixture in the fuel which causes excess friction resulting to the piston rings and cylinder linings to wear out faster than expected. Always maintain an ideal fuel to oil ratio in your gas tank to avoid excess wear on your pistons.
CDI Electrical System
A chainsaws electrical system is not that complicated since almost all chainsaws use a CDI (Capacitor Discharge Ignition) system that automatically regulates the proper flow of voltage to the spark plugs. The CDI system is composed of a high voltage passive capacitor that multiplies the electricity being produced by the small field winding that is built into the chainsaws main chassis. Usually, the field windings only produce between 6 to 12 volts DC as the engine runs on idle in which is exponentially multiplied to 500 to 600 volts by the capacitor and is accurately controlled by a regulating circuit within the CDI system. The alternating current is then switched on and off by a magnet that is embedded into the flywheel that also serves as a cooling fan for the main engine block. As the magnet revolves around and passes the capacitor’s mount point, it interrupts the flow of electricity, momentarily cutting off the flow of voltage resulting in a spark gap effect. To check if the voltage is adequately delivering the right amount of electricity into the spark plug, you should pull out the spark plug and connect the ignition line back to it as it is grounded to the main engine chassis, but note that you have to be very careful in doing this since it does produce a substantial amount of electric shock if you accidentally come in contact with it.
As you pull the start string, you should notice the spark gaps will produce a blue streak of electricity on the spark plugs. If the sparks produced are weak, they would look a bit yellowish instead of bluish, which means that the spark plugs are already worn out and need replacing. However, if you already replaced new spark plugs and still get the same result of not having a solid blue spark, you should consider to check the electrical grounding on the chassis or if unavoidable, replace the entire CDI system with a new one. Also check to see the spark plug clearance gap since chainsaw spark plugs have a required clearance gap when it comes to spark plugs depending upon the engine model which require a particular spark plug type.
Chain and Cutting Bar
Maintaining the chain and cutting bar is fairly effortless as most chain saws today have a built in lubricating system that does that for you while the clutch system is engaged. Always make sure that the auto lube system is functioning so that it can deliver the right amount of oil on the chains and bar to maintain it’s smooth run along the path of the cutting bar. Always check for the chains condition since it tends to loosen up from time to time due to frequent use, it is best to always make the proper adjustments to the cutting bar to augment chain slack. If your chainsaw has an automatically adjusting chain tensioner, it is best to always check the tensioner if it is adequately applying the proper pressure on the chains without being too tight that it puts a substantial amount of load while the chain is running on the bar. If you are using standard cutting chains, it is best to always sharpen them after each and every use to maintain their durability and efficiency. Although there are premium quality carbide steel cutting chains that are available in the market that need less maintenance compared to ordinary factory issued cutting chains, you should know what your specific need would be in regards to the work that you will be tackling.
As a summarization, doing the right method of preventive maintenance will prolong your chainsaws durability and extend it’s serviceability for as long as you will be needing it, given that you should make regular checks on some of the issues concerning it’s performance as soon as you start to notice that something is wrong with the way that it runs. And since parts do not come cheap, taking ample care of your chainsaw will give you much more mileage in terms of saving up on costs of having to deal with down time as a result of breakdowns. Also consider learning a few basic skills in learning how to fix your chainsaw instead of always sending it to the shop for proper maintenance as you can easily do this by yourself in the comfort of your own back yard since it is also a learning experience on your part.