If you buy a gas chainsaw you buy power, durability and versatility.
But, you also buy noise, weight, fumes, maintenance and an increased risk of injury.
So, whilst I’m not by any means trying to put you off buying a gas chainsaw, it is important that you are aware of all the pros and cons that apply to these machines.
How does a gas chainsaw work?
These chainsaws are powered by small two stroke (two cycle) engines. Two stroke engines are lighter than 4 stroke engines and produce more power relative to weight, which is why they are used in chain saws.
The essential difference between two stroke and four stroke engines, as far as the user is concerned, is that the two stroke engine runs on a mixture of gas and two-stroke oil, usually at a 50:1 gas:oil ratio.
The engine drives the chain around the chainsaw’s guide bar at high speed.
The chain consists of links with sharpened teeth and these cut through the wood as they are applied to it by the operator. The rotation of the chain and the cutting action of the teeth keep the saw in contact with the tree or branch being cut.
There is also a reservoir for chain oil. This releases oil onto the chain as the chain rotates. The purpose of this is to keep the chain lubricated so as to reduce wear and to help it cut efficiently and without snagging.
How big and powerful are gas powered chainsaws?
Engine power is normally stated in cubic centimetres (cc) or sometimes horse power (Hp). Engines generally range in size between 33cc for a basic consumer model to 80cc or more for a pro model. Power output can range between and about 1.6Hp for a 33cc engine and 6.5 Hp for an 80cc engine (see Simetric for conversion data.)
Gas chainsaw cutting bars are generally between about 12 to 24 or more inches (30 to 60 cm plus) in length.
These models can weigh between about 7 to 20lbs (3 to 9kg).
How does a gas chainsaw compare to an electric chainsaw?
On the whole, a gas powered chainsaw of similar weight and bar length to an electric model will be more powerful and cut more smoothly because of the higher speeds at which the chain is driven.
But, remember, gas powered chainsaws require more maintenance than electric chainsaws and are generally heavier and noisier and, of course, emit exhaust fumes.
They require a few hefty pulls on the starter cord to get them going and, due to their higher power, are more likely to kick back and injure the operator.
Given the two stroke nature of the gas chainsaw’s engine, they can be difficult to start if left unused for some time, as the carburetor can get blocked.
In addition to the carburetor, the engine also has a number of other parts (e.g. spark plug, air filter) that will require monitoring and maintenance.
One of the greatest advantages of gas powered chain saws is that they can be used practically anywhere out of doors. They can be transported deep into the woods for logging or be used around the home for trimming trees. Many homeowners with fireplaces or wood stoves choose the gasoline saw as a tool for cutting firewood.
As long as a well maintained gas chainsaw is supplied with the gas and oil mixture (with oil to lubricate the chain in a separate chamber) it will continue cutting.
Many of these saws are designed for all day use. They are rugged and can quickly cut a 75 foot tall tree into 18-24 inch sections for splitting into firewood.
Features to look out for
Look out for the following safety and convenience features on gas powered chainsaws:
- Air injected engine – this works to ensure the air filter remains clean and that the engine can therefore run more efficiently.
- Low emission engine – You may not need to have a chainsaw that complies with the emission limits of the California Air Resources Board (CARB). But it will undoubtedly be more comfortable for you and those around you if your chainsaw has an engine with low exhaust emissions.
- Starting mechanisms – Higher specification models have electronic ignition systems. Also look out for compression release systems on high powered models, as these enable you to turn the engine over as you pull the cord. Without compression release you may find high powered models almost impossible to get going.
- Automatic oiling of the chain – keeps the chain oiled as you work, so that you don’t have to keep remembering to do it manually.
- Anti-vibration or vibration dampening technology – a high level of vibration, especially over prolonged period, is the main factor in causing user fatigue (and thus increasing the risk of injury). This technology reduces the vibration levels.
- Cutting length – As a rule of thumb, a chainsaw can usually fell a tree with a diameter twice the length of the cutting bar. But also bear in mind that when you are cutting on the ground (logs etc), a longer bar will reduce the amount of bending down you need to do.
- Balance – Very often it is not the weight of a chainsaw that determines how easy or hard it is to use but its weight distribution, or balance. Look for a machine with an inline-design, that is where the engine is seated directly behind the cutting bar.
- Safety – look for safety features that comply with the American National Standards Institute’s B 175 Standard
- Inertia chain break – this is a particularly important safety mechanism. It operates to stop the chain spinning if the saw kicks back when it snags or hits a knot, for example.
- Top handle – Some newer models have a top handle rather than the traditional rear handle design. This is especially good for downward cutting motion and therefore useful when lopping tree limbs and working off ladders.
Gas powered chainsaws – Best Uses
There is of course a spectrum of potential uses for chainsaws and there are overlaps in that spectrum where more than one kind of chainsaw may be adequate for the job.
But broadly, you should consider a gas chainsaw if:
- You need to cut down or log mature trees, especially hardwoods,
- You are likely to need to use your chainsaw fairly regularly,
- You are strong enough to handle the extra weight of a gas powered model and the effort of pulling the recoil starting cord,
- You don’t mind having to mix up oil and gas to fuel the chainsaw,
- You are comfortable with maintaining the chainsaw or at least keeping an eye on things like whether the spark plug or air filter need cleaning or changing,
- You need a chainsaw that you can use for extended periods and/or outside the range of electric power,
- You don’t mind the noise or there are no noise limitations in where you are going to work.
Type of gas powered chainsaws
Gas powered chainsaws can generally be classified as being for domestic/consumer use, for heavy use or for professional use.
Consumer-use models will generally have bars up to about 14 inches in length and engines of around 32cc to 35 cc displacement.
Heavy-use models have bars up to about 18 inches long and engines between about 35cc and 55cc.
Professional grade models have bars up to 24 inches or more and engines with 80cc or more displacement.
Having worked through this information you should have a general idea about whether a gas powered chainsaw is going to suit your needs.
If you think it is, then the next step is to work out which level of gas chainsaw is going to suit you. This, of course depends on what you want the chainsaw to do.
Whilst it is important not to buy a machine that is underpowered for the use you want to put it to, it is equally important to buy a machine that is overpowered and and difficult for you to use.
The Husqvarna 450
One of the best, if not the best chainsaw for the consumer market, is undoubtedly the Husqvarna 450.
This chainsaw falls in the middles of the categories identified above and features a 50.2cc, 3.2 HP engine and 18 inch bar.
Read our fully detailed Husqvarna 450 chainsaw review here.
The best of the rest
In addition to the Husqvarna 450, I’ve gathered together a careful selection of other great gas powered chainsaws. Ranging from small consumer to professional grade saws, there is definitely something for everybody in that list.
Read our selection of the ‘best of the rest’ – ten other great gas powered chainsaws, here.
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