How Rich Can You Mix Oil/Gas And Still Have A Working Saw?

lxskllr

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This is just a matter of curiosity. I've been puzzling over how much oil got in my new ms170, and it occurred to me the previous owner may have used a whole one gallon mix bottle, and finished it off with gas. Tank capacity is 8.5oz, and a one gallon mix bottle is 3.2oz. Could a saw start fairly easily and run with 5oz of gas and 3oz of oil?
 
If it would start, which is doubtful, it would smoke to high heaven. Ask the previous abuser how many quarter cups are in a cup. Any answer other than four will indicate what hell the unit has endured.
 
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Yea, I thought it might be too rich to really run, but it seemed like something someone would do if they weren't familiar with 2stroke engines. They make it about as easy as it can be to deal with, but I guess even making stuff for the dumbest people you'll still have someone a little dumber come along. I have about 4 tanks of my mix in it so far, and still have oil coming out of the muffler.
 
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Presumably. It sounds alright, but it doesn't have anything adjustable aside from idle. It's fixed from the factory.
 
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Maybe. I was figuring my usual mix would clear it up, but it may just take longer than I expected. It's definitely better than when I first got it, but it's still a little smokey, and oozes oil. Piston looked good. I removed the spark arrestor, and you pretty much remove the muffler for that. No gasket which is a little strange.

The whole saw's a little weird regarding it's life story. The chain and bar looked factory issued and unused. Everything looked brand new including the air filter, but has heavy scuffing on the bottom. The fuel it came with looked very rich to me, but that was just looking at it in the tank. It started right up and ran, so I didn't bother dumping it. It's like someone bought it, put in a oil heavy mix, maybe ran it for a minute out of wood, then decided they didn't need a saw.
 
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That's a good idea, but it's a clamshell saw. That's more effort than I want to put into it. I'll just run it, and it should clear up eventually. I'm hoping it gets a little more power as it clears out. It feels a little weak compared to my other saws similar in size.
 
Most saws are tuned to run on 50:1 from the factory, 25:1 is about the most oil you might get away with running without adjusting the carb, if it would even run at all on that much oil, or rather that little gas.

Some oils do not evaporate and burn off easily: castor, Red Armor are a couple. Such oils will condense in the muffler and crank case. It will not cause a problem in the crankcase because it gets blown out at high rpm. Long periods of full throttle will help burn off what's in the muffler.
 
The 170 was notorious for gunking up the spark arrestor. Every one I ever serviced for clients. Maybe they set the carb too rich at the dealer. Anyway. You already checked that. I run my saws at 40 or 45:1 even though they are 50:1 rated. Keeps them cooler in the heat out here. Lasts longer.
 
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The 170 and 180 have some of the worst emissions. The Echo 352 had them beat, but they still updated it to the 3510 strato port, while Stihl keeps cranking out the global warming generators at a much higher rate.
 
Sounds like its spent most of its life bashing around in the back of a pickup or bed of truck etc.
Oh, fuel is low, top it up, then not used, evaporates over time, oh look, its low, top it up, do that a few times, and your going to have a pretty oil rich mix.

dump it and put fresh in, warm it up, cut with it, by the time you have gone thru a fresh tanks worth, you should be well on your way for burning off whats left in the muffler, which is where the smoke will now be coming from.
 
not exactly fuel:oil mix... however the answer is, somewhere around 100% oil
ran the boxer out of diesel a few weeks ago, used a VP premix can to get diesel because I didnt bring a can (mistake number one)
got the truck stuck and had to come back with another truck the next day, got diesel in a real can on the way, used said real can to fill the boxer up and forgot about the VP can
well, about 3 weeks later it bit me in the ass, filled my 194 up with diesel and didnt notice it till all the smoke on startup
reason 10000 I like to run my own stuff, NOBODY will pay attention to what fuel they are putting in a saw, listen to the skidsteer to make sure its running right, check the chip box isnt overflowing, or double check that they connected the trailer right

it is amazing how many times ive had to stop a job because people are stoopid!
p.s if you somehow run bar oil or diesel in a saw, simply pour the "fuel" out on a neighbors plants, re fill with mix gas and send it!
 
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They will run on diesel, but not on gas when there's too much mix oil. Diesel evaporates and burns much more easily than mix oil, but has too low of an octane rating.
 
not exactly fuel:oil mix... however the answer is, somewhere around 100% oil
ran the boxer out of diesel a few weeks ago, used a VP premix can to get diesel because I didnt bring a can (mistake number one)
got the truck stuck and had to come back with another truck the next day, got diesel in a real can on the way, used said real can to fill the boxer up and forgot about the VP can
well, about 3 weeks later it bit me in the ass, filled my 194 up with diesel and didnt notice it till all the smoke on startup
reason 10000 I like to run my own stuff, NOBODY will pay attention to what fuel they are putting in a saw, listen to the skidsteer to make sure its running right, check the chip box isnt overflowing, or double check that they connected the trailer right

it is amazing how many times ive had to stop a job because people are stoopid!
p.s if you somehow run bar oil or diesel in a saw, simply pour the "fuel" out on a neighbors plants, re fill with mix gas and send it!
Consider if the boss needs to train people more and label fuel cans.
 
There's a whole variety of different forms of fuel/oils. Anywhere from oil that doesn't burn off easily in a chainsaw (castor oil), to oil that does (most synthetic oils), to fuels that are oily (kerosene), to fuels that dissolve oil (gasoline), to hydrocarbons that are only liquid under high pressure (natural gas). Fuels and oils can be tweaked to do just about anything. There's thousands of different combinations, arrangements and mixtures of Carbon, Hydrogen, and Oxygen that make unique fuels and oils.

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Some people can't be helped. I get that. I stay away from them, as much as possible, or don't allow them to exercise judgment and make decisions.
 
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