Small engines undergo a lot of abuse and inevitably develop a few quirks over time. Everyone has had a lawnmower that doesn't run quite as smoothly as it used to or a chainsaw that takes too much effort to start. While these problems have solutions, it may not always be worth the trouble to repair them.
Of course, small problems sometimes indicate bigger underlying issues. If you have a chainsaw that struggles to get going, it might indicate a more serious issue with the engine. And that's without even addressing the frustration and lost time involved whenever you need to get any work done. When you work with chainsaws daily, it can pay to recognize when hard starting is more than just a nuisance.
Understanding the Normal Start Process
Even if you've used chainsaws and similar small engines for a while, you may not have a good feel for how the start process works or why you need to take certain steps. The details will vary from saw to saw, but starting from cold typically involves closing the choke and, if present, using a primer bulb and decompression valve.
These steps are necessary because the most significant challenge your chainsaw's engine faces on a cold start is pulling in enough fuel to ignite the spark. Colder fuel has a lower vapor pressure, making it much harder to burn. Likewise, cold fuel will flow less freely into the carburetor, so the primer valve helps to get fuel where it needs to go manually. These extra steps theoretically reduce your starting pulls.
In some cases, an engine may take a few pulls to start, even if nothing is wrong. For example, it can be harder to start on a cold day. Likewise, not all chainsaws include a decompression valve, so the compression remaining in the cylinder may mean your first few pulls require more effort. However, you may have a problem if your engine fails to start after several pulls or it struggles to run once it fires.
Common Causes for Hard Starting
The simplest problems that can cause a chainsaw to struggle relate to common maintenance issues. Poor fuel quality, a clogged air filter, or a failing spark plug will make your saw difficult to operate or, in extreme cases, prevent the engine from starting. Consider changing your fuel and, if you're comfortable with minor mechanical work, replacing the air filter or spark plug.
If these steps don't solve the problem, the engine may have a more severe problem. All engines need compression, fuel, and a spark to start, so any hard starting issue likely traces back to one of these three factors. Possible culprits can include a leaking or clogged fuel line, faulty ignition module, or even internal issues with the engine causing a loss of compression.
Unfortunately, solving more complex engine issues often requires significant expertise, especially if you want to avoid simply throwing parts at the problem. If a few basic maintenance tasks don't get your chainsaw firing right up again, it's time to have a professional small engine repair shop help you hunt down the underlying problem.
Contact a company like Rocky Mountain Diesel & Auto to learn more.