I could have sworn I read a thread here one time discussing chainsaws where a manufactured fuel (i.e. not mixing gas and oil in your garage) was mentioned. But I can’t turn it up in a search.
Anyway I seem to remember mention being made of this fuel not creating the gummed up, hard to crank after periods of non-use problems associated with the gas-oil mixture.
After several near heart attack episodes with my chainsaw, I thought I’d try to revisit this idea. Does such stuff exist? Is is hard to find? Does it do the things I vaguely remember or were those just delusions I had in my last near-aneurism bout of cranking my chainsaw?
The usual design of two-stroke engines is such that they require some oil to be mixed in with the fuel. There are two ways of doing this: 1) premix the fuel/oil mixture in the proper ratio as you are familiar with, or 2) have separate fuel and oil tanks and a metering system to mix the fuel and oil as the engine runs. Some two-stroke engines are made to use crankcase oil, just like a four-stroke and don’t need to burn oil, but this costs all of the mechanical simplicity that makes a two-stroke so desirable for small yard tools, and they are quite rare, as a result. Four-stroke engines are not common in smaller tools, though they are frequently found on larger lawnmowers and snowblowers. Two-stroke engines are preferred in things like chainsaws and weed whackers because they generally have a higher power-to-weight ratio than a comparable four-stroke making the whole tool lighter for a given amount of power output. I suspect you are thinking of a metered fuel-oil mixing system.
It may be the tool and not the fuel mixture. I’ve had some cheaper 2 strokes that where always a pain to start.
My Stihl starts every time. Even after sitting for a year. Even in the dead of winter. I don’t even bother draining the fuel. It always fires. And I’m at 11,200.
Premix seems popular in Europe - Aspen is one brand I could find. It’s essentially white gas (same as the old-style Coleman lantern/stove fuel) mixed 1:50 with 2-cycle oil.
The main benefits seem to be the lack of all that stuff put in by Chevron/Shell/etc for cleaning your injectors and oxygenators such as MTBE. In other words, it’s pure gas that’s not been messed with.
The brave and foolhardy might try mixing Coleman fuel with oil. I’m not that crazy.
For what it’s worth, your saw might just need some good old-fashioned cleaning and maintenance. A friend was over this past weekend with his chainsaw to help us remove some trees, and he uses whatever gas is at hand. His saw never needed more than three easy pulls to start. Pay attention to that oil ratio - my friend’s saw is nearly as old as I am, and it runs at 1:32. Prolonged use on 1:50 would be harmful.
Ah, see there’s the rub. My father-in-law walked me through doing that on a couple of small engines before he died. Cleaning little needle valves and diaphrams is not my idea of a good way to do anything, but loose little needle valves, etc. I regard doing so right up there with taking the cover off my PC – only to be done in dire emergencies as there is lots of shit to screw up in there by the ignorant (AKA rainy).
When I ran saws everyday we’d break them down and do a basic cleaning every evening. Granted, we were working them pretty hard (firewood and trail clearing) but saws like to be cleaned. And most is just basics, not really playing with the guts of the engine.
It also definately helps to get a quality saw. We’d only run Husqevarna, Stihl, or Jonsered, but I think at least one of those bought one of the others.
Alright, I’ll quit being such a girl and get a good saw and learn to clean it. Thanks for all the recommendations on name brands.
So is it pretty much everyone’s opinion that I must be incorrectly remembering some comment about premix fuel. I could have sworn I remembered there being an additive other than oil that did the lubricating.
Most likely. According to gotpasswords, premixed two-stroke fuel/oil is fairly common in Europe, but I’ve never seen it here in the States. All the chainsaws I’ve ever seen either require you to premix your own or (rarely) have a metered mixing system in which you add the oil and gas separately. Basic maintenance on two-stroke engines isn’t terribly difficult. As in most things, an ounce of prevention is worth a pound of cure: use only fresh, good-quality gasoline with the octane rating recommended by the manufacturer, use two-stroke oil specifically intended for your application in the proper ratio, follow the manufacturer’s break-in procedure and keep the tool clean and properly lubricated to specs. Basic engine maintenance includes removing, cleaning and oiling the air filter periodically, pulling and checking the spark plug for fouling and checking for loose fasteners, worn or damaged parts and draining and flushing the fuel tank to keep the crud from building up. The owner’s manual will specifiy what sort of specific maintenance the tool requires and how often each should be performed.
We always did oil mix and since we had two different saws that ran on two different ratio mixtures, all gas cans were labeled clearly and mixing was done as soon as we filled up the cans. If becomes second nature after a while, but we used the saws every day.
Wood chips find their way into everything near a chainsaw, including your fuel tank. It’s messy, but it’s a good idea to overfill the fuel tank every 3rd or 4th filling, to float out the wood chips.
When I took my grass trimmer in for a fix when it would run and quit, run and quit, it turned out the spark arrestor was sooted up. The mechanic told me to periodically run it flat out for a minute or so. It’s counterintuitive to flog the poor thing, but it’s good for it.