ChainSaw Oil-2 cycle

[MikeBurr]

Got a new Stihl chain saw and the saleman said it required a 50:1 mix, ok. Checked the oil I used for my old saw and it said it made a 40:1 mix. So I go down to the store and get some oil that say's 50:1, must need more oil to gas mixture. Then I visit another store and see a large container of 2 cycle oil and in the attached measuring bowl the 50:1 would require less oil than a 40:1. So what is the ratio really measuring??

TC33D

 

[jdkid]

Hi ya
most mixes are gas/oil so 50/1 would be 50 parts gas to one part oil . Older chainsaws might run 25/1 the other thing is make sure the oil is for mixing at 50/1.most 50/1 oils are more raceing based and burn cleaner etc etc i have 2 saws 1 runs 20/1 and the other runs 25/1 but i use a 50/1 oil in both .Use a good 2 stroke oil and good bar lube and ya will have no probs
catch ya
JD Kid

 

[GlueGuy]

Mike 50:1 is 50 parts gas to one part oil, and likewise with 40:1.

You "should" go by volume, but most 2-cycle oil containers are marked in ounces. There are "approximately" 96 ounces (of oil) in a gallon, so to get a 50:1 mixture, you would put (approximately) 2 ounces into a gallon of gas.

To get a 40:1 mixture, the same gallon of gas would require 2.4 ounces of oil. Alternatively, you could take the same 2 ounces of oil and add .83 gallons of gas.

Much easier way is to go by the instructions on the container. They usually list the quantities for different ratios.

The GlueGuy

 

[brewerbob]

Your Stihl dealer has oil put up in containers that, when added to one gallon of unleaded, will yield the correct mixture. I believe that these are packaged in 6 packs.
Bob

 

[cowboydoc]

Yes you are right Bob I use them for my stihl chainsaw. Makes it really easy to do.

 

[MikeBurr]

Thanks, makes a little more since now. At least I can still use the few 40:1 mix I have left, just add a little more gas. Thanks all....

TC33D

 

[jdkid]

Hi ya
if you have 40/1 mix mixed up in tins/cans DON'T ADD MORE GAS to try and make it 50/1 if the oil is not up to the task your new saw will be dead in hours, worst case i have ever seen saw only lasted 3/4 of a tank of gas guy got the mix realy out of line. stihl ,husky and other makes all have there own oils all will work great in any saws i'll say the same going the other way don't mix 50/1 down to 25/1 you will find it's smokey and plugs will foul
catch ya
JD Kid

 

[fishman]

I would add a note of caution here. I was told by my dealer NOT to use outboard motor oil, even the modern TCW3 formulation. He said it was not designed to be used in air cooled engines. So my outboard oil goes in my outboard, and I have 6.4 oz bottles of Stihl oil to mix in my one gallon can of gas.

Anybody else heard this concern?

 

[mrolson]

Oops, I hope not. I figured what goes in my $14K Merc is OK for my $200 Chain Saw. I haven't had any problems.... Yet.

Mark

 

[Bird]

fishman, I won't claim to understand the differences, or know what bad results could occur, but I think all the dealers are saying the same thing; outboard motor oil is NOT to be used in air cooled engines. So I don't. I think you'll also find the same warning on most of the oil containers.

Bird

 

[Bud]

Bird
In 1965, when I quit boating, I had about 30 quarts of Quicksilver outboard motor oil left from boating. I'm still trying to use it up in my chainsaws, grass whips, and anything else that takes a gas oil mix. Everything has held up well, no problems.
Bud

 

[Anonymous Poster]

DO NOT USE OUTBOARD OIL IN YOUR CHAINSAW!
(my caps key was stuck and that is the story I am sticking to!)

Outboard motors are cooled by water and as such they run cooler than a chainsaw or weedwhipper etc. When you get your chainsaw good and hot in the middle of a log and it is hot outside you are asking for trouble. The outboard oil is formulated for use in a more "controlled" environment and breaks down at high temperatures. You are not supposed to use air cooled oil in an outboard either but I can't remember why.

Now a question for those that are braver than me:
If I run out of fuel in the middle if a cut I let my saw cool down before resuming work because I figure it probably got a little too hot when it starved out of gas. Should I just gas it up and go or does letting it sit for a while keep me out of trouble?

 

[Bird]

I don't know whether gassing the chainsaw up and going again immediately would hurt the saw; don't intend to find out either. I'll let mine cool awhile first./w3tcompact/icons/laugh.gif

Oops, sorry, you said that question was for those braver than you, so I don't qualify./w3tcompact/icons/wink.gif

Bird

 

[ccatfish]

Just to restate an earlier comment a little more clearly, high end chain saws like Stihl and Husquvarna (sp?) require 2 cycle oil specially formulated for high RPM engines. I believe Stihl saws rate in the 14,000 rpm range, while some of the "other" brands can be around 9-10,000.

On the running out of gas thing, emptying a tank when the engine is running at a high RPM is really bad. Especially the high end saws won't forgive you too many times before they sieze.

 

[jdkid]

Hi ya
yes stihl husky dolmar etc etc all go up to 14000rpm but you will find that is max rpm non loaded ,working rpm for most saws is around 9000 rpm a chain can only cut up to so many feet per sec then it chokes on sawdust and won't cut .ok as for refueling when hot most books say don't but that is more for fires same as not smoking if you ever pull a saw to bits you will see the head and piston are very thin so there cooling is fast most of the time while you refuel you move sticks ,have a smoke or drink,walk to ya gas and back to the job at hand so in most cases you saw would have cooled abit anyway
catch ya
JD Kid

 

[art]

Mike I totally recommend using the factory oil for these saws. I don't know how much you use it or what model you bought but the price of the oil the manufacturer sells is small compared to premature wear from generic oil that doesn't stand up. The diference between the 40 to 50 to one oils is that the one that takes the 50 to one mix is machined better.

 

[RobertN]

This is a interesting issue. I used to ride dirt bikes. I mixed 76 premium with Hi-Point oil(per the oil spec), one of the best oils at the time. I had some left over from my ride the day before, and tried to run it in the chain saw. It ran terrible! I ran to the gas station and mixed up some Stihl oil per spec, and the saw ran great!

So, no I stick to Husky or Stihl oil, and mix per the oil spec

RobertN in Shingle Springs Calif

 

[skent]

The only problem I had was with my LawnBoy 2 cycle lawnmower. Three years ago, to save money, I stopped buying the LB oil and started mixing the oil from the quart (outboard oil) and had the ratio correct (32:1) and the mower would run for 15 or 20 minutes then stop. It didn't sieze. . . it starved (just like it was out-o-gas). This went on for several attempts. Let the thing sit for 10 minutes and it would restart and run fine. Local repair shop said it was a bad ignition module ($60). Part couldn't be returned if it didn't fix it. I didn't buy it.

An old guy that went to our church said to mix a new load of fuel using Lawnboy pre-measured cans and drain the old gas. Said the fixed jets in the carb couldn't handle the viscosity of the outboard oil and would run lean (or rich-I dont remember). Was jetted for lawnboy 32:1 gas oil mix. I did what he said and it worked. (its also called 'low ash' oil)

Now when you look on my lube shelf you will see LawnBoy 32:1 oil, Poulin 40:1 oil (Chainsaw and string trimmer), Mantus 50:1 for the little tiller, all in premeasured manufacturers bottles. Have never had the problems again. All my gas cans are clearly labeled to their use and ratio.

Steve

 

[RobertN]

Bird,
They put different additives in the oil for different applications.

As a example, in my Harley, they say do not use car oil; use a oil formulated for a air cooled engine. If one is not available, use oil formulated for a diesel; it has more high pressure, high temp additives. The oil companies have taken many additives out of "car" oil so they dont show up in the emmisions.

For a water cooled 2-stroke, the temperatures the oil operates would differ from those in an air cooled motor, so there will be different additives.

RobertN in Shingle Springs Calif

 

[Bird]

Skent, several years ago Consumer Reports, in their testing of the lawnmowers, decided the LawnBoy wasn't a very good mower; not enough power for tall grass. But after buying a new Toro w/Tecumseh engine in '69 that was junk, in '74 I bought a used LawnBoy, changed the spark plug every couple of years, and put new points and condensor in it one time in 15 years. It still looked and ran great when I gave it away when we sold the house. And I have a friend that was still using his after 25 years. I don't know about the new ones, but as far as I'm concerned LawnBoy used to make the best lawnmowers on the market.

Bird