Basically, there are only 3 aspects that you have to keep an eye out when it comes to finding some of the things that are giving you major headaches when it comes to maintaining your chainsaws proper running condition. The carburetor, the electrical system and the pistons which are considered as interrelated to one another in keeping your chainsaw running as smoothly as possible without having to keep on guessing as to what is affecting your chainsaws performance in regards to doing your own chainsaw repair. Gas powered chainsaws mainly use a two stroke engine that use premium petrol and a mixture of fuel lube to keep it running at it’s optimal temperature without overheating as much as possible. Now, there are a few aspects that you really have to consider in regards to your chainsaws operating capacity and regardless of it’s brand, you really have to keep in mind that brand has little to do with how you use your chainsaw.
The aspect of how you “properly” use and maintain your chainsaw to ensure you that you are getting the most from using it and since maintaining is not a simple matter of just revving it up and using it once the engine starts as the problem can easily stem from your misuse of your chainsaw. Most people just go about using their chainsaw without giving it a little bit of “breathing” time which means that you have to pre-heat your chainsaw prior to using it by letting your engine run on idle speeds for at least 2 minutes or so so that the pistons and piston rings can adjust to its optimal running temperature. Consider it as comparable to that of doing your regular exercise in the morning in which you have to do your required warm ups unless you want to strain a muscle or pull your hamstring in the process.
Most people make this mistake that results in inflicting damage on the pistons, piston rings and the cylinder bore sleeves since it will result in metal fatigue in the long run to the aforementioned engine components. Forcing your chainsaw to perform it’s job without without giving it the proper “warm up” it needs will eventually shorten it’s lifespan and the service that it will provide you. As a general rule, always follow your manufacturers prescribed usage and maintenance that is appropriate in regards to how your chainsaw should be used. Following these guidelines will enable you to enjoy the use of your chainsaw without voiding it’s warranty on parts and service, however, if the time does come that your chainsaw would eventually come to a point that it’s warranty will lapse, you may want to consider to try fixing it yourself.
Most carburetor problems in chainsaws are usually caused by dirt clogging the fuel lines that end up being ingested into the intake manifold. This usually is a clear indication that the air filter is not properly filtering out the particulates, more particularly the fine saw dusts that manage to get into the carburetor, mix in with the fuel and eventually clog the fuel nozzle. There is no easy way around this but that of removing the carburetor and taking it apart to clean out every little component that can contain minute debris of particulates that can be making air and fuel flow very irregular, causing your chainsaw to run with difficulty.
A clogged carburetor can deliver an irregular amount of fuel and air mixture that can cause your chainsaw to run hotter than how it usually does. The incorrect fuel to air mixture usually makes you think that your chainsaw is running at it’s best performance, and since two stroke engines are usually very smoky when it comes to their exhaust fumes, most people who find the substantial smoke a bit too inconvenient that they tend to adjust their chainsaws carburetor’s air regulator to more or less reduce the amount of smoke produced by the engine. They do this by increasing the air that gets mixed with the gasoline, unknowingly to them, an increase of air will make your chainsaw run hotter than it already is.
It is an undeniable fact that two stroke engines need a fuel lube mixture to maintain the lubrication of the top pistons and it’s piston rings and without this, you will end up with a dry piston top that can cause overheating and eventually fry up your engine. Cleaning your carburetor is just as simple as taking it apart and cleaning each and every small component and checking all the nooks and crannies that might contain foreign matter that might affect the carburetor’s efficient way of handling the flow of air and fuel into the engine. Carburetor repair kits are easily available almost everywhere that would correspond to your particular chainsaw model and it is advised to change all the gaskets and rubber seals in your carburetor once you take it apart to ensure that you will never have to worry about leaks.
Also, you may want to take good care in putting the carburetor back into it’s proper place, most especially the flanges in which it attaches itself to the intake manifold, since there are times that people forget to check this area for leakages. Even just the slightest leak in this area can increase your chainsaws running temperature which is also one cause of engine overheating. Applying a high temperature silicon sealant in this area prior to completely tightening the carburetor down should ensure that leaks will not be a problem once you have completely secured this area. The best method of applying high temperature silicon in this area is to put a substantial amount around the flanges and let it settle down for a minute or two to make sure that it builds up a consistency before finally tightening it down.
The CDI Electrical System
The CDI (Capacitor Discharge Ignition) is probably one of the most efficient electrical ignition systems that were integrated into engines in the last 20 years since it replaced the contact point as a means to regulate the discharge of electricity into the spark plug. The contact point system was primarily mechanically based upon the main crankshafts revolution and the flow of electricity was regulated by the way of cutting the power on and off through a cam that is built into the crankshaft. Electrical power is produced by a magnetic field winding that produces a substantial amount of electricity, but not enough to discharge the needed spark gap into the plugs. The voltage produced by the magnetic winding is exponentially multiplied by a capacitor which in turn fires up the spark gaps.
In the case of the CDI system, electricity is produced from a magnetic strip that is built into the flywheel which is also designed as the engines cooling fan. The main induction coils are much smaller compared to older designs and electrical interruption is done electronically rather than mechanically. With each time that the magnet passes the induction coil, the amount of electricity is multiplied as the induction coils already have a built in capacitor and the electronic module efficiently regulates the voltage at a constant rate regardless of the chainsaws running speed. But do not be very complacent about it’s efficiency, though it is very efficient, it does manage to breakdown from time to time due to heat that is produced by the engine. In such cases, the usual fault comes from the electronic module that controls the voltage.
CDI electronic modules are very easy to replace since you just have to pull them out and replace them with a new one but since most of these CDI systems come in sets, you may as well replace the whole system to make sure that everything will work accordingly to it’s product specifications. Most common symptoms of having difficulty in starting a chainsaw stem from such problems as a faulty electrical system given that your carburetor is in perfect running condition. You can easily determine if your electrical system is slowly bogging down as you can check the color of the sparks that it is producing by removing the spark-plug and plugging it back to the high-tension cable and try starting the chainsaw to observe the sparks. Try replacing the spark plugs with new ones and make sure that the gap clearance are the same with the engine’s requirements. You can do this by using a filler gauge to accurately determine it’s clearance. If all else does not improve the way how your chainsaw runs, then it is only the time to consider replacing the CDI system.
The Piston and Piston Rings
The only function of the piston and it’s rings is to maintain the ideal combustion chamber pressure and if you should find the integrity of your piston’s aspect questionable, it is best to perform a simple cylinder bore pressure check. A cylinder bore pressure gauge can come on handy for situations such as this to easily determine your pistons integrity in being able to hold adequate chamber pressure. A cylinder bore pressure gauge looks similar to that of an average tire gauge, except that it has a thread that snuggly fit into where the spark plug is placed. Fastening it securely into place and giving the pull string starter a quick few tugs would compress the piston and induce pressure into the combustion chamber which will then be recorded by the pressure gauge. If you should ever determine that the pressure should fall short from what is conservatively accepted as prescribed with your manufacturer’s requirements, you may want to check the cylinder bore for wear along with the pistons as well.
Another way to determine if the piston or piston rings are leaking is to pour some gasoline into the chamber and wait for some signs of the gasoline to leak down to the lower parts of the piston. If this should happen, Replacing the piston along with the piston rings should be the best alternative to avoid any problems of loosing chamber compression. Since you already have taken the main cylinder block apart, you may also want to check the cylinder bore clearance to ensure that it still can accommodate the piston’s size within it’s tolerable clearance measurement. If the cylinder sleeves should fall short of the adequate allowable clearance, consider replacing the cylinder block as well.
Learning to do your own chainsaw maintenance can not only save you a few bucks in servicing costs, it is also a good way to learn a few valuable mechanical skills on your part as well in regards to keeping your chainsaw in tip top running condition. You will eventually learn a lot of things when you open up your chainsaw and understand things that you never seem to knew before in regards to the way of how it runs, in which you will appreciate it’s complicated working dynamics. Although it is hard work, it is a very educational and fun way of learning nevertheless.