Chainsaw is running,but doesn't cut.what is possible causes of this?
Depends on what you mean when you say 'it doesn't cut'.
If you pull the trigger and the chain goes around, but it won't cut anything, there are a few possibilities, depending on whether it's been serviced or otherwise opened up:
* The chain is dull: The individual teeth do get dull over time. There are DIY kits at many hardware stores, usually with an alignment jig and a file/sharpening-stone like rig to re-sharpen a tooth. You'd need to sharpen them all. (Or take it to a service center and let a pro do it).
* The chain is on backwards. In some cases, people servicing the chain have put it on reversed. The cog that drives the chain will engage the chain with it mounted either way. The chain should go away from you on the top of the blade, and back toward you under the blade. With the engine OFF, check the teeth to make sure they are pointing the way the chain goes. If this is the case, removing the chain and reversing it will likely fix the problem.
You pull the trigger, the chain moves, but it stops (with motor still running) as soon as you put the chain to the wood.
* Clutch needs adjustment: There is an engagement clutch that will let the chain be at rest at idle but engages it at higher RPMS. You can up the RPMs more before engaging the blade and see if that works. If this works either run it that way, or if the RPMs are excessive, you may need to get the clutch adjusted or replaced.
* Chain is really loose and skipping on the drive cog when load is on the chain. If this is the case, there'll be a lot of noise at the base of the blade. This is incredibly dangerous. If this is the case, pull the saw away and shut it down immediately. There is a chain tension adjustment for the saw. It may not have been re-tensioned after previous service. Better, turn the saw off, and see if you can pull the chain away from the bar more than a tiny bit in the middle of the bar. If you can, get your manual and adjust the tension first. Then try again.
Chain never moves, even when you rev the saw engine:
Most likely the clutch is either frozen, damaged, or mis-adjusted, or the engine is mis-tuned and can't get to proper RPMs to engage the clutch. The manual for the saw should have instructions for adjusting both the max RPMs and the idle, both of which are important for the saw to run properly, not redline, and not stall on idle.
Also, for spotty power or stalling - check the fuel. If it's been in the saw for a long time, dump it (dispose of properly) and put in new fuel. Make sure you're using the right mix - chainsaws are 2-stroke and need a fuel-oil mix - make sure the right mix is in the gas before filling. Failure to match it up right can damage the engine very quickly. You can also check the spark plug - they can get fouled if left for long periods for a last chamber of oil-gas to slowly evaporate, or if run with the wrong fuel mix.
There should also be a fuel filter, likely at the end of a fuel line leading into the fuel tank. If you don't remember replacing it in recent times, replace it. They'll get clogged over time and limit fuel flow, cutting power.
Likewise, there'll be an air filter. If you've been cutting in conditions that are dusty, which includes most conditions where there's this big spray of sawdust coming off the saw, then you can clog the filter easily and cut off good air flow the the piston. Blow it off, at least, and/or replace it.
Finally, if the saw has been around a few years, check the fuel lines. They tend to get hard and brittle over time, and can start leaking, which will inevitably mess with consistent power. They are stiff, and often a real PITA to get onto the small spigots, but can make a big difference on performance if upgraded to new ones.
Nov 02, 2015 |