# Gas mix ratio for Stihl MS 390



## Kenster (Feb 22, 2013)

I was about to go fill up my chain saw gas can and I put in two 2.6 ounce oil bottles.  I then realized that one bottle was 1:40 and the other was 1:50.  I don't have any more right now. 
How can I adjust the amount of gas to be able to use this?  Is there a drastic difference in the two types of oil? 
Should I just dump it and start over? 

Thanks!


----------



## Bigg_Redd (Feb 22, 2013)

Kenster said:


> I was about to go fill up my chain saw gas can and I put in two 2.6 ounce oil bottles. I then realized that one bottle was 1:40 and the other was 1:50. I don't have any more right now.
> How can I adjust the amount of gas to be able to use this? Is there a drastic difference in the two types of oil?
> Should I just dump it and start over?
> 
> Thanks!


 
What is the ratio in the can right now?  Between 40:1 and 50:1?  If so, use it up.  Your saw will never know.


----------



## Kenster (Feb 22, 2013)

The two gallon can was empty.  I put in one each of the two kinds of oil and I'm now in town about to put two gallons of premium gas in the can.  Sounds like it won't hurt to have a mix of 40:1 and 50:1. 
Good to know. 
Thanks!


----------



## TreePointer (Feb 22, 2013)

2.6 oz. bottles are for making one gallon.  So if you poured both bottles into two gallons, then it is as Bigg_Redd stated-- somewhere between 40- and 50-to-one.

If you poured both into one gallon, then it's somewhere between 20- and 25-to-one.


----------



## Researcher1 (Feb 22, 2013)

put in 2 gallons and it won't make any difference.


----------



## wh401 (Feb 22, 2013)

You'd have a 50:1 mix no matter what type of oil it is. Oil itself isn't the mix ratio, the amount of oil mixed with the total amount of gasoline is. So, two 2.6 bottles of oil in two gallons of gasoline would be 50:1 no matter how you do the math. So your good.


----------



## TreePointer (Feb 22, 2013)

wh401 said:


> You'd have a 50:1 mix no matter what type of oil it is. Oil itself isn't the mix ratio, the amount of oil mixed with the total amount of gasoline is. So, two 2.6 bottles of oil in two gallons of gasoline would be 50:1 no matter how you do the math. So your good.


 
Good point.  Kenster, are you sure that 40:1 bottle isn't a 3.2 oz. bottle?


----------



## Sean McGillicuddy (Feb 22, 2013)

So when do you put the gas stabilizer in?


----------



## TreePointer (Feb 22, 2013)

My 2-cycle oil has stabilizer in it.


----------



## BobUrban (Feb 22, 2013)

I am guessing you have one oil bottle that is 2.6oz. (50:1) and one that is 3.2oz. (40:1) I have the same thing because I could not get the 2.6 one time.  Just run it - no problems and better to run a little on the rich side than the lean anyway. 

As mentioned, most quality 2 stroke oil has gas stabilizer in it but I add Stabil marine grade(green stuff) to my larger gas cans before I go to the pump.  Just a little insurance as this gas goes into all my toys and not all are 2 cycle. 

Your saw is safe.


----------



## mikefrommaine (Feb 22, 2013)

1 gallon is 128 ounces. It's all math from there.

(128*2)/(2.6+3.2) =44.137

If you want your final mix to be 50:1 add 2.03125 gallons of gas to 5.2 ounces of oil. 

Or 2.26 gallons to 5.8 oz if that's what you already put in the can. (for 50:1)
Or 1.8125 gallons to 5.8 oz for 40:1

Not gonna make a big difference as everyone else pointed out.


----------



## ScotO (Feb 22, 2013)

I buy my 2-cycle oil by the quart or gallon, and it's easy to measure out with one of these.......







It's called a Ratio Rite measuring cup. Made specifically for measuring out 2 cycle oil (it has both metric and standard graduations on it). I use it for my snowmobiles, my saws, my weedeaters, my leafblowers, etc. Comes in really handy, especially when mixing up a 5 gallon gas can.........


----------



## ScotO (Feb 22, 2013)

Here's a good deal on ebay for the RR measuring cup right now.....

http://www.ebay.com/itm/RRC1-Ratio-...Parts_Accessories&hash=item27cf0a703b&vxp=mtr


----------



## Kenster (Feb 22, 2013)

TreePointer said:


> Good point. Kenster, are you sure that 40:1 bottle isn't a 3.2 oz. bottle?


 
Pointer, you raised a good question so I went out and pull the bottles out of the trash.  The bottles are exactly the same size but one is labeled 2.6 oz and the other is 3.2 oz.  Both for one gallon of gas


----------



## EatenByLimestone (Feb 22, 2013)

I always run 40 to 1.  It doesn't hurt to run a bit too much oil.  My plug stays clean too.

Some of my equipment specifies 50 to 1, some 40 to 1.  It's easier to run only one mix.  

Matt


----------



## bogydave (Feb 22, 2013)

Clicked on the Amsoil ad at the bottom.
Couldn't find any 2 cycle oil for  mixing  chain saw gasoline? 
What gives?


----------



## TreePointer (Feb 22, 2013)

Yeah, it's hidden under the Motor Oil button:

Amsoil.com > Motor Oil > 2-Stroke

http://www.amsoil.com/shop/by-product/motor-oil/2-stroke/


----------



## bogydave (Feb 22, 2013)

What I meant was
No small bottles for 1 gallon or 2 gallon of gasoline, so I don't have to measure.

Ever try to measure 2.6 oz or 3.2 oz of 2 cycle oil with the wife's measuring cups ?
Hard to be accurate & even worse if you get caught. 

Alway wonder how much stays in the measuring cup.
How long will it drip as you wait to get it all out?

I like the small bottles so I can add some gasoline, shake & add it to the jug.
That way I think I get it all & have a good mix


----------



## ScotO (Feb 22, 2013)

bogydave said:


> What I meant was
> No small bottles for 1 gallon or 2 gallon of gasoline, so I don't have to measure.
> 
> Ever try to measure 2.6 oz or 3.2 oz of 2 cycle oil with the wife's measuring cups ?
> ...


Why not save 5 or ten of those little bottles, and get a gallon jug to refill all of them......makes it even easier than the ratio rite!


----------



## mikefrommaine (Feb 22, 2013)

I use an old self measuring stabil bottle. Makes for quick measuring at the gas station.

Heres another


----------



## bogydave (Feb 22, 2013)

Scotty Overkill said:


> Why not save 5 or ten of those little bottles, and get a gallon jug to refill all of them......makes it even easier than the ratio rite!


 
Thought of that.
How to get an exact measure to refill the bottles?

Maybe a big syringe .

Hey, *(light bulb*) that got me thinking
I have some big syringes somewhere in the shop. (from the old oil & water sampling days)
>............
Back, Found one. 2oz/ 60 ml
This should work & be pretty accurate.





Thanks Scott ! !


----------



## ScotO (Feb 22, 2013)

bogydave said:


> Thought of that.
> How to get an exact measure to refill the bottles?
> 
> Maybe a big syringe .
> ...


That'd be perfect, BD!


----------



## mikefrommaine (Feb 22, 2013)

I have a few hundred of those in the basement, use them all the time in the garage. Great for wood glue too.  Though Once you put oil or PB blaster in them they don't work very smoothly for long.


----------



## Boog (Feb 22, 2013)

I saved two little 3 oz Stihl bottles that had the old style clear strip down the side.  I don't see those around any more.  I just refill them with 2.6 oz from a hoard of pints I bought long ago.


----------



## bogydave (Feb 22, 2013)

Lets see if I got this right.

I mix in 1 gallon jugs . 
128 / x = 50 / 1
50x =128
x = 128 / 50
x =2.56

I'll save the small 2 cycle oil bottles & re-fill them.
& save some with a   gallon of good synthetic.
I'll be set  for a while. 

2.7 oz wouldn't' hurt
I usually put .9 gallon in the jug & rinse the small bottle with gas to get it all.

All that said.
Now?
What's the consensus on what is "the best 2 cycle oil"  for chain saws?




I got 6 of the 2.6 oz bottles when I bought the Stihl blower,
$15.54 for 6 pack of 2.6 oz bottles.
$2.59 for 2.6 oz.
$1.00 per oz.  
$32.00 per quart
$128 per gallon 



Definitely time to start refilling the small bottles.

The Amsoil  *INTERCEPTOR 2-Cycle Oil, * synthetic is only $40 a gallon/


----------



## BobUrban (Feb 23, 2013)

BogyDave - that is interesting and math can't lie??  I never did the math and I am not even sure what I pay for the little silver jugs of "Gold" evidently at 100+$$ per gallon.  Makes 4$ a gallon for fuel seem cheap!


----------



## MasterMech (Feb 23, 2013)

bogydave said:


> What I meant was
> No small bottles for 1 gallon or 2 gallon of gasoline, so I don't have to measure.
> 
> Ever try to measure 2.6 oz or 3.2 oz of 2 cycle oil with the wife's measuring cups ?
> ...


 
One of my biggest complaints with AMSOIL is that they don't offer up Saber Professional in a squeeze & measure type bottle or in a 2.6oz bottle.  They advertise it as a 100:1 oil but if you do the math, one of their little pillow packs for 1 gallon mix (1.5oz) comes out to be 80:1.  Probably because it's a real PITA to rinse the packs out with gas if you're anal about the mix like me and Dave.   I'm still running the stuff and still liking it tho.  Plus it's a cool electric blue color. 

http://www.amsoil.com/shop/by-product/motor-oil/2-stroke/saber-professional/


----------



## fabsroman (Feb 23, 2013)

bogydave said:


> Lets see if I got this right.
> 
> I mix in 1 gallon jugs .
> 128 / x = 50 / 1
> ...


 
Yeah, not really comparing apples to apples here because we all know that buying bulk usually gets you a discount. Have not priced a gallon of Stihl HP Ultra mix, but willing to bet that if you buy it a gallon at a time that it will be cheaper than $128 a gallon. Thing is, I use one, maybe two, 2.6 oz bottles a year. Let's go with the high estimate of 2 bottles a year.

5.2 oz of mix per year
128 oz per gallon
128/5.2 = 24+ years

Buying a gallon of mix will last me until my kids are done with college. I still have tons of it left over from buying the saws and the trimmer. Bought the HP Ultra 6 pack to get the extra warranty coverage.

With that said, anybody know how much an actual gallon of HP Ultra mix costs?


----------



## bogydave (Feb 23, 2013)

fabsroman said:


> Let's go with the high estimate of 2 bottles a year.
> 
> 
> Bought the HP Ultra 6 pack to get the extra warranty coverage.


 
That's why i bout the 6 pack/ warranty.
But will be buying a quart or gallon & refill  the bottles.

Went thru about 8 or 9 gallons last year.
Have other than a chainsaw to feed too. 

I'm a cheap skate


----------



## fabsroman (Feb 23, 2013)

bogydave said:


> That's why i bout the 6 pack/ warranty.
> But will be buying a quart or gallon & refill the bottles.
> 
> Went thru about 8 or 9 gallons last year.
> ...


 
8 or 9 gallons of mix? You have got to be doing something for a living with this stuff or using a ton of it in play vehicles. That is just one heck of a gasoline bill using that much mix. At 50:1, that means you used almost 500 gallons of gasoline. At current prices, that is close to $2k in gas for feeding everything.

Would love to know what else you are feeding with 500 gallons of gasoline.


----------



## bogydave (Feb 23, 2013)

fabsroman said:


> 8 or 9 gallons of mix? You have got to be doing something for a living with this stuff or using a ton of it in play vehicles. That is just one heck of a gasoline bill using that much mix. At 50:1, that means you used almost 500 gallons of gasoline. At current prices, that is close to $2k in gas for feeding everything.
> 
> Would love to know what else you are feeding with 500 gallons of gasoline.


 
LOL
Of mixed gasoline.

Lets say 26 oz if 2 cycle oil.

Sometimes more if I fly much.
2 hours uses about 6 gallons of 50:1 mix gasoline:


----------



## fabsroman (Feb 23, 2013)

bogydave said:


> LOL
> Of mixed gasoline.
> 
> Lets say 26 oz if 2 cycle oil.
> ...


 
Man, that is awesome. Made me wonder if I could do something like that here in Maryland. Highly doubt it though. Would probably require a cavity search, psychological screening, and $10k in licensing and insurance.


----------



## wh401 (Feb 25, 2013)

+1 Amsoil saber professional oil. I've been running it for the last 5 years in all my 2 stroke stuff...chainsaws, leaf blowers, trimmer. The leaf blower and trimmer are Stihl 4-mix products with OHV's. They're very particular about having two much oil and they've run great for me on this stuff. I also add a little bit of Sta-Bil or Seafoam to each mix to promote stabilization of the fuel.


----------



## nate379 (Feb 25, 2013)

I dump 1/2 a qt in a 5 gallon and call it good. No need to get all anal measuring down to the 0.001 oz.


----------



## lukem (Feb 25, 2013)

I have one of those tall shot glasses with a scratch/sharpie line for measuring out my own. I originally wanted a test tube but this was about the same (tall and narrow makes it more precise...and can see through it), sits flat on the workbench, and is much easier to come by. The sharpie line wears off after a while, but there's I scratched a line with a file that I use to re-mark it every so often.

I dumped a 1 gallon mix container in and marked it.....now I just buy a quart and am good for a couple years.

I used to buy the one-shots, but they want crazy money for those.

Easy.


----------



## MasterMech (Feb 25, 2013)

"48 packets of Saber Pro on the wall, 48 packets of oil!! Take one down, pass it around, 47 packets ......"

Yeah I'm good for awhile.


----------

