These two Chainsaws
are made for the Home-owner, to be used for trimming trees and cutting
firewood. Home-owner Chainsaws may have Bars up to 16" and engine displacement
up to 40cc.
They are low-priced Chainsaws
and not meant for daily use in a wood lot. You may find them on sale for
$100.00 or less.
Electric Chain saws
are quieter and may be better suited for use by Women and in areas with
neighbors nearby. They are lighter and don't require pull-rope starting
or mixing oil with the gas.
But they often lack the power
of many Gasoline models, and have the nuisance of a trailing Electric Cord
begging to be cut off.
Features:
You may desire certain features
which some gasoline Chainsaws have and others do not. Older used Chainsaws
may have very few features. Features tend to raise the price.
Bar length: 12" - 48"
Determines how big a log you
can cut. Theoretically, a 14" bar should be able to cut a 28" diameter
log. But in reality, it will most likely be very under powered for the
task. It is more realistic to limit a 14" bar to a 12" diameter log.
Displacement: 30cc - 120cc (2-
8 HP.)
This is the term used to measure
the amount of air space in the Cylinder when the Piston is down. The larger
this space, the more air it can hold, the more gas can be mixed with the
air, and the larger will be the explosion.
Automatic Brake:
This feature is pretty common
now. A Lever mounted in front of the operator's wrist stops the chain in
case of a "Kickback".
Kickback Nose:
This device is mounted on the
front of the Bar to make it more difficult for a Chainsaw to violently
kick back toward the operator. Some experienced operators consider it a
nuisance.
Weight: 9 - 20 pounds.
This is a big deal !
If you opt for a heavy Chainsaw, you'd better eat your Wheaties. After
several hours of cutting, arms exercised on a Computer Keyboard will feel
like they're about to fall off.
Vibration Damping:
Some Chainsaws have Springs
or Rubber Grommets between the handles and the engine to minimize vibration
in your arms.
Easy-Starting:
Compression Release or other
methods make it easier (and safer) to pull the Starting Rope.
Automatic Bar-Chain Oiler:
Manual oiling of the cutting
Chain and Bar depends on the operator to push an oiling device. An Automatic
system which constantly feeds Chain Oil to the Bar is convenient and more
dependable, which should prolong the life of these parts.
Bar Sprocket:
This Chain Sprocket on the nose
of the Bar has become pretty standard, but some cheap Chainsaws may still
lack this feature.
Chain Adjustment:
Chain adjustment is usually
done by loosening several Nuts, then turning a Screw or Bolt, and retightening
the Nuts. A new feature is the ability to tighten the Chain without
using any tools, which are easily misplaced or lost.
Fill Locations:
Some chainsaws (like the two
above) have the Gas or Oil Fillers at a location that makes access difficult,
inviting Gas or Oil spillage.
Choke-Start Switch:
A convenience is one Switch
which controls both Choking and Acceleration; as opposed to this sort of
method:
The 2 Chainsaws shown
above have these very precise starting instructions:
(1) - Turn on Switch
(2) - Turn on Choke max
(3) - Press Primer Bulb 10 times
(4) - Lock Throttle "ON"
(5) - Pull Starter Rope 4 times
(6) - Move the Choke to mid-position
(7) - Pull Starter Rope 4 times
- Engine should start
(8) - After 10 seconds, release
Throttle Lock
(9) - Turn Choke "OFF"
. . . . . Saw wood
SAFETY: not enough can be said
Not only can you be injured
by the obvious sharp speeding Chain, but less obvious dangers are lurking:
ALWAYS wear tough Leather
Gloves . They will help protect you from the sharp chain, the hot exhaust,
and the splinters, scrapes, and bruises associated with Firewood.
High Leather Boots will help
protect your feet, ankles and shins from moving logs and Firewood. Their
traction soles will also help you maintain good footing when working on
uneven or stony ground. The last thing you want is to lose your footing
while holding a running chainsaw.
A Full Face Shield is the best
eye protection you can wear, and it will also help prevent flying chips
from getting inside your shirt.
Ear Plugs or Ear Muffs which
muffle the sound and protect your hearing.
Chainsaws
usually have "2-cycle" Engines, which are lighter and more powerful-per-pound
than are "4-cycle" Engines. A "cycle" is considered to be one complete
directional movement of the Piston within the Cylinder.
When the Piston goes down, it
is considered a cycle. When it goes back up, it is considered a second
cycle. So down-up= 2-cycle, and down-up-down-up= 4-cycle.
When the 2-cycle Engine on the
left has its Piston go down, it sucks gasoline in from the Carburetor.
When it goes back up it closes
the fuel port from the Carburetor, discharges exhaust through the exhaust
port, closes the Exhaust Port, and compresses the Gasoline mixture. Then
the spark Plug fires, explodes the gasoline, and forces the Piston back
down which sucks gasoline in again.
The inefficiency of a 2-cycle
Engine comes from the fact that gasoline enters the Cylinder while the
Exhaust Port is still open. This allows some of the gasoline to escape.
This waste is minimized by the upward protrusion on the head of the Piston
which limits the gasoline going straight across the Cylinder, and out the
Muffler.
In the 4-cycle Engine there are
mechanical Valves that are opened and closed by a rotating shaft which
has cam lobes on it. In the graphic above, the Exhaust Valve is open
allowing exhaust to escape out the Muffler.
This is the 4-cycle
sequence:
1 - The
Piston moves down, the Intake Valve opens admitting gasoline from the Carburetor,
the Intake Valve closes.
2 -
The Piston moves up compressing the gasoline, the Spark Plug fires and
explodes the gasoline.
3 -
The Piston is forced down by the explosion.
4 -
The Exhaust Valve opens. The Piston moves up, pushing out the exhaust.
The Exhaust Valve closes.
The 2-cycle Engine does not have
the weight or complexity of a valve "train" or of a lubrication system.
But that makes it necessary for the operator to mix 2-cycle oil with
the gasoline. Plain gasoline will damage these
Engines!
The usual mix
is about 3 ounces of 2-cycle oil to 1 gallon of gasoline. The burning oil
is why Chainsaws tend to smoke so much. Some operators use only Synthetic
2-cycle oil, which minimizes the smoke. It has been rumored that some Synthetic
2-cycle oils may also extend the life of the Engine.
Storage:
You should not mix more 2-cycle gasoline than you expect to use in a month.
And if you plan to store your Chainsaw for longer periods, you should remove
the Spark Plug and put a teaspoon of 2-cycle oil in the Spark Plug hole.
Then slowly pull the Starter Rope to coat the moving parts with a film
of the oil before you replace the Spark Plug.
Trouble:
Too much oil in the Gasoline will cause the Spark Plug to "foul" and make
your Engine erratic. If you have Chainsaw trouble, click HERE.
The inconvenience of having to
add 2-cycle oil to the gasoline is outweighed by the power and lightness
of 2-cycle Engines, which keeps them the prime candidate for Home-owners
Chainsaw power.
Those tiny cans of 2-cycle oil
that get dumped into a
gallon
of gasoline cost about $1.40
for a 3-ounce container.
That's about $15.00 a quart
! !
Next time -
open that tiny container, check
how full it is; use it and then cut the top off at the oil line. Then buy
a QUART for about $2.00 and use the cutoff teenie $1.40 can for a measure
. . . and save $13.00.
Then you can take the $13.00
you saved and order Goodies from us.  |
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Home-owner's
Chainsaws
