Chain Saw, Part 2b
Saw Maintenance
As a Natural Resources/Vo-Ag teacher since 1971, my school program usually had at least 3 chainsaws each year. Students and adults would also bring in saws for basic repair and maintenance. Personally, I professionally cut timer for landowners with small woodlots. I also have cut and old firewood since 1977. In 1979, I took over the forest management program on our 500- acre tree farm, which my wife and I purchased in 2003. (It previously belonged to my father.) During these years, I purchased and used a number of saws of different brands, thus I have seen or experienced a number of chain saw problems with a variety of saw styles and manufacturers. I am not an expert, but I am trying to share what knowledge I have gained over the years.
As we continue the maintenance segment there will a guest writer to present information about fuel and the fuel system.
External Saw Maintenance:
1. Make sure the chain brake engages and releases properly. If it doesn’t return to the saw dealer for repair.
2. Check and clean the chain brake, remembering to always disengage brake before removing.
3. The new high RPM saws have anti-vibration features: inspect for loose bolts, broken handles, and worn out or loose rubber shock bushings. Repair as needed.
4. Under the sprocket is an aluminum chain catch for your safety. Make sure the catch has not been removed. The chain catch and the wide bottom rear handle protects the hand from chains that break or jump the bar.
5. Mufflers need to be checked for loose bolts and blocked spark screens. Since saws are 2 cycle engines, the fuel is mixed with oil. The unburned carbon can plug the exhaust screen or even the side exhaust port in the cylinder.
6. Today, most 2 cycle engines use a 32:1 to 40:1 gas oil mix. Older saws run 16:1 ratio: therefore these had more carbon buildup. In shop class, we had a lot of McCulloch saws that would start but the engine would die out under pull throttle. We would remove the muffler and scrape the carbon out of the exhaust port, using a wooden (popsicle) stick so as not to scar the cylinder wall. The piston needs to beat top-dead center. Please don’t use an air hose because it can blow dirt back into the cylinders.
Bar Oil and Lubrication:
1. New saws come with automatic oilers while older saws had thumb pump oilers to lubricate the bar.
2. Always make sure the oil reservoir is full.
3. To check to see if the oiler is working, use a piece of cardboard set up in from of the saw. Start the saw and run the saw full speed for 30 seconds. The cardboard will show an oil line if the oiler is working.
4. If the oiler isn’t working, take the side cover, bar, and chain off. Check for dirt in the bar oil slot and the oil slot on the saw.
5. Start the saw without the bar and chain to see if the oiler is pumping oil out the oil slot.
6. Before heading to a saw shop, check (normally on the bottom of the saw) the oil screw. Try to make some adjustment to solve the problem.
7. Use a virgin grade bar oil, not recycled / reprocessed bar oil. It costs more, however the viscosity of virgin oil will extend the life of your bar and chain.
8. Adequate viscosity of the bar oil is necessary with the high speed of the rotating chain as it tends to throw off the oil as the chain rotates.
9. Poor quality bar oil or lack of bar oil burns up the saw bar and damages the chain.
10. Please! Never fill the saw with used motor oil. Used oil has dirt and metal shavings in it AND no viscosity
11. Inside the saw is a plastic/nylon metering gear to pump oil out of the oil slot. Some of these gears break down due to dirt in the oil tank or heat from the engine. Depending on the saw brand, replacing the gear can be a major expense.
12. Never sit your saw chain on concrete. The lime in the concrete will eat at the neoprene gasket on the bottom of the saw. Oil will leak out and make a messy oil spill on the concrete. This repair will take 2 hours at the saw shop at $45 – 80 / hour.
Fuel System:
1. Two cycle engines require a good fuel (gasoline) and oil mix to lubricate the internal parts of the engine.
2. Purchase a good quality – it doesn’t have to be a saw brand oil mix. Beware, some saw manufacturers require that only their fuel / oil mix be used to guarantee the saw warranty.
3. I purchase a good product that includes a fuel stabilizer.
4. I only mix up 2.25 gallons of fuel mix at a time, which lasts me 1 – 4 weeks.
5. All fuel, even with fuel stabilizers, get old, causing major fuel system problems.
6. Beware of trade shows where the sales rep will ‘save you hundreds of dollars on their 2 cycle oil mix’. Usually, one container of their mix can be used to make 500 gallons of mixed gas! You either make a whole batch or try to calculate the ratios required. These products come with a ‘full guarantee’ if your engine is damaged while using their product. However – the guarantee is if your $800 saw engine is damaged, they will refund the cost of their $8.00 product. Too bad about your saw!
7. Two cycle saw engines are a multiple position engines, which means it can run on its side or even upside down.
8. Being a multiple position engine requires a weighted fuel filter in the fuel tank. This needs replacement every year.
9. When storing the chain saw for a long period of time (more than 1 month), empty the fuel tank by running the saw completely out of fuel. The weighted fuel filter can dry out and harden. This will need replaced before starting the saw again.
10. When storing the saw for a long period of time, store it in the plastic saw case to keep rodents from causing damage.
Ethanol Fuel: This section is being written by guest Mike Reiboldt. Mike is a certified Stihl technician and small engine repairman. See his business card at the end of this section.
Ethanol Fuel
Michael Reiboldt: Owner of Anchors Point Repair Gold Certified Stihl Chainsaw Technician Small Engine Master Mechanic
Today’s fuels are much different than they were just 20 years ago. There are many government mandated detergents and additives that affect the fuel over time. Most gas at the pump is mixed with ethanol and is labeled accordingly. In the past the shelf life of gasoline was 6 months before any degrading occurred and 2 years before the fuel became unusable. Today’s ethanol fuel begins to degrade at 1 month. After 1 month, the ethanol in the fuel begins to separate from the gasoline and starts to draw moisture to it as it becomes a solvent. The ethanol begins to deteriorate the fuel system. Fuel lines, gasket, plastic floats, rubber diaghrams and plastic internals found inside most small engines begin to literally be dissolved. Fuel lines will become very brittle and I have had them crumble in my hand. This all begins after just one month of the fuel sitting. After 6 months the fuel is in such a bad state that it will only have about 40 percent of its original burn quality. The water which is drawn to the gas also causes problems in small engines causing hard starting, coughing engines, white puffs of smoke; and in some cases not starting at all as it can foul the spark plug or even block the good fuel from getting through the carburetor.
There is some hope. There is a fuel additive called Startron which has an enzyme in it that removes the ethanol. Regular fuel stabilizers do not fix the ethanol problem such as Stabil. Some gas stations are also beginning to offer Recreation Fuel which is labeled with a red handle and is usually 89 octane. Recreation fuel does not have ethanol in it. This fuel still has the mandated detergents and other additives in it, but has a much longer shelf life of 8-10 months before a major loss of fuel performance, and it does not degrade your fuel system.
Let’s talk about fuel octane. All small lawn and garden engines should be run with 89 octane or higher gasoline. Chainsaws, string trimmers, hedge trimmers, leaf blowers and so on are usually higher compression and require this octane for a stable fuel burn. Lower octane fuels burn dirtier and can cause carbon build up, lower power, and a sympton called pre-detonation which can cause engine damage.
Some companies such as Stihl, Husqvarna and Echo sell cans of non-ethanol gas which are expensive, but they still have a shelf life of under 2 years. This will be marked on the cans.
My best advice to help is to drain your fuel systems if your equipment is going to sit for over a month. Do not buy more gas than you are going to use in a month. Remember all of today’s fuels have a shelf life, if left in your machines too long, it will get expensive.
Thank you,
Mike.
Mike’s home business is Anchor Point Repair where he repairs small engines, including chain saws. He also sells chain saw bars and saw chain, sharpens saw chain, sharpens knives and scissors.
He will have a booth at the May 16th Homestead Rendezvous held in Bergholz, Ohio.
Maybe you just need a new saw:
If your chainsaw requires a number of repairs, compare the total cost of repairs, parts and labor, in addition to the routine maintenance of replacing bar, chain and sprockets versus purchasing a new saw. With labor rates of $65 – 95/hour, it doesn’t take long for repairs to cost more than a new saw. Before starting repairs, be sure the parts are available. Many of the homeowner saws supposedly have parts, but they are ‘out of stock’ or ‘no longer available’.
A friend of mine had a small engine repair shop in a little shed behind the house. A customer brought in a small chain saw for repairs. The mechanic figured out the cost of repairs and labor would be over $125 but a new saw only cost $80. The customer insisted on getting the repairs, saying that his wife bought him the saw for their anniversary. The mechanic said, “So, buy a new saw for $80 and take her out to movies and dinner with the money your saved.”
Think with your wallet, not your heart.
That’s all for now,
Happy cutting,
Bob
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