Math Check Needed

[vegaome]

Howdy All,

After reading a couple days worth of feul mix threads I still don't know what to mix my feul at or which oil to use. I did figure out that if your going to try different mixes to check your gas first. I went to the only station in town that advertises Non-Alcohol feul and bought the best stuff they had 89. They are always out of premium after I get off work, actually anytime I'm there.

I poured one gallon in a clear glass jug and marked her. That way I know where Im starting from. Also I can look for water or other impurities floating around.

Now I was working on a MAC 10-10 the last couple of days and the owner said to mix her at 40 to 1. I used Husky mix that said 50 to 1 mix 2.6 ounces on the bottle. I poured out all I could get from the little bottle into a glass measuring cup I bought at WAL-MART and it said there was 3 onces. Any of you ever had this happen? Maybe WAL-MART's measuring cups are off? For this MAC I ended up mixing 12 onces of feul to .3 ounces of the husky mix. I just needed enough to test her out and the MAC seems OK.

Now for my echo saws I'm going back to OPTI-2. I poured a gallon of gas into my glass jug and got out the OPTI-2 mix. It said 50 to 1 also but was only 1.8 ounces. Into the WAL-MART measuring cup and.......yup 1.8 ounces. Go figure. Do the major brand names put 3 ounces in the bottle but label them 2.6?

Anyway I thought it would be good to make a mix chart for the major brands and here it is. Maybe someone has already made one of these for folks and I did not find it. You may need to check the math but i thnk its correct. I will have to make another for the OPTI-2 mix.


2 CYCLE FEUL MIX RATIOS

1 GALLON MIX RATIOS (128 OUNCES)
50:1 128/2.56 ounces
45:1 128/2.84 ounces
40:1 128/3.2 ounces
35:1 128/3.57 ounces
32:1 128/4 ounces
30:1 128/4.26 ounces

.8 (4/5) GALLON MIX RATIOS (102.4 OUNCES)
50:1 102.4/2.04 ounces
45:1 102.4/ 2.27 ounces
40:1 102.4/ 2.56 ounces
35:1 102.4/ 2.92 ounces
32:1 102.4/ 3.2 ounces
30:1 102.4/3.41 ounces

.75 (3/4) GALLON MIX RATIOS (96 OUNCES)
50:1 96/1.92 ounces
45:1 96/2.13 ounces
40:1 96/2.4 ounces
35:1 96/2.74 ounces
32:1 96/3 ounces
30:1 96/3.2 ounces

.5 (½) GALLON MIX RATIOS (64 OUNCES)
50:1 64/1.28 ounces
45:1 64/1.42 ounces
40:1 64/1.6 ounces
35:1 64/1.82 ounces
32:1 64/2 ounces
30:1 64/2.13 ounces

.25 (1/4) GALLON MIX RATIOS (32 OUNCES)
50:1 32/ .64 ounces
45:1 32/ .71 ounces
40:1 32/ .8 ounces
35:1 32/ .91 ounces
32:1 32/ 1 ounces
30:1 32/ 1.06 ounces

.125 (1/8) GALLON MIX RATIOS (16 OUNCES)
50:1 16/ .32 ounces
45:1 16/ .35 ounces
40:1 16/ .4 ounces
35:1 16/ .45 ounces
32:1 16/ .5 ounces
30:1 16/ .53 ounces

.09375 12 OUNCES (STANDARD/small BEER CAN)
50:1 12/ .240 ounces
45:1 12/ .266 ounces
40:1 12/ .300 ounces
35:1 12/ .342 ounces
32:1 12/ .375 ounces
30:1 12/ .400 ounces

Good night

v/r
Mike

 

[spacemule]

I've always wondered if mix ratios are calculated by weight or by volume.

 

[Lakeside53]

hmmmm.... Opti 50:1 is 1.8 Fl ounces...?? I'm suspicious. I'm staying with my 2.6 per gal for 50:1

Ben??

 

[litefoot]

Another nice chart would be how many gallons of fuel to add to each little 2.6 oz bottle to get your 50:1, 40:1 and 32:1 ratios. I'll work on that and post it later this evening. I've got a meeting to go to.

Edit: Never mind...that was too easy. For a 2.56 oz bottle of fuel mix:

50:1 ratio...1 gal of petro
40:1 ratio...0.80 gal of petro
32:1 ratio....0.64 gal of petro

Maybe add a tad less fuel since you rarely get all the oil out of those tiny bottles.
Joel

 

[ray benson]

The Opti 2 comes in a 1.8 oz. pouch that is supposed to be used with 1 gal of gas.They say - it provides proper mix for all 2-cycle equipment regardless of OEM mix ratio. Mix contents with 1 gallon of gas. Contains fuel stabilizer. Smokeless and fully compatible with oxygenated fuels (gasohol). Never used any but if I did it would be 2 pouches per gal of gas.

 

[Lakeside53]

oh.. that's what they mean... Personally, I don't trust it..

 

[vegaome]

Howdy Ray Benson,

The local saw shop guy swears buy it. He told me he has used it for years and never once had a problem. I'm worried that two packs would be to much. Wouldn't that put the mix at 25 to 1? I can try it, but I will have to retune my carbs, You don't think it will hurt anything?

Also that MAC 10-10 starts on the first pull cold everytime, so far. That saw is so old I though it was going to wear me out but I'm surprised. I thought it may have benn a fluke so I went out to the trailer after work and....yup first pull.

Good night

v/r
Mike

 

[ray benson]

2 pouches would be 3.6 oz.
128/ 3.6= 35.5
I usually run between 32 or 40 to 1 mix.Except the old Homelites- they get 16/1. But I will stick with MX2T.

 

[Lakeside53]

I'm not Ray, but I will interject.

No, the mix is not 25:1. Opti is saying "use our 1.8 oz in one gallon and it will run the same as 2.6oz (50:1) of another oil".

What they are really saying is "mix at 71:1"... (roughly) "it will be o.k.".

Sorry... I'm not going to take the risk for a few pennies, and, who will deal with the warranty or failure if it does damage?

I know several guys that use opti at 50:1 with no problems, but they are all moving (or have moved) to 2T (still at 50:1).

Another data point: Stihl says (off the record) that you can use their new synthetic at 80:1 in their 4-mix Blowers, but NOT in 2-stroke saws... for saws use 50:1... On the record they say, just use it at 50:1 in all equipment.

 

[woodshop]

For what it's worth, I too have experimented in the past, and found that the little one gallon mix bottles of Stihl oil I measured exactly DID all seem to have a little more than the 2.8 they say if you hold the thing a while and let it all drip out. I figured this was simply Stihl knowing that not everybody will take the time to let every drop fall, and designed it so that a quick pour would yield at least the required amount for 50:1. I no longer use the little bottles, buy standard Stihl mix oil by the quart and mix 40:1 for my 60cc and under saws, and 32:1 for my 395 and MS460

 

[JUDGE1162]

vegaome very nice chart, but who mixes 12 OUNCES batch of gas, that is not even enough gas to fill my tank once. 455 take 15 oz and the 575 takes 23 oz. And good look messuring .24 oz of oil to add as your chart show a small error in oil about in that size batch can change the ratio ery quickly if you are off by .026 oz more now you are at 40:1 not a big deal, but if you are .026 oz less now you are running at 60:1 that could be a big deal. And .026 is such a small about (the amount that sticks to the messuring cup (the oil residue sould easily be more then .026. .026 oz is the size of a drop.

Do you self a favor don't mix batch which are less then a 1/2 a gallon otherwise a small error in oil amount could cause major problems. even at a half a gallon only 0.14 oz of oil is the diffrece between a 50:1 ratio and a 40:1 ratio. And only a 0.20 oz less and you are at 60:1. Do yourself a favor mix one gallon at a time if you don't use it in 2 month wait till your truck is like 3/4 full and dump in the extra gas (such a small amount will not hurt your truck) or use it to start you brush pile fire. And start a new batch of saw gas.

 

[scottr]

Measure

Judge1162 , it's easy to use a teaspoon or a tablespoon to measure small amounts of oil .

 

[ShoerFast]

I've always wondered if mix ratios are calculated by weight or by volume.

Fluid Ounces, or 128 per gallon US

 

[JUDGE1162]

Judge1162 , it's easy to use a teaspoon or a tablespoon to measure small amounts of oil .

I guess but a teaspoon is still 0.17 oz even with a messuring spoon which was 1/2 a teaspoon at 0.085 oz it is still very hard to get to 0.240 oz within 0.02 oz. (1.4 teaspoons for a 50:1 ratio) and To get that accurate you would need a medicine droper in CCs or mLs (6.8 cc of oil for a 50:1 ratio). And even then, by time you account for the oil that sticks to the dropper you can still be off quite a bit in a small batch mixture.

Again that small of a mixture is less than a tank of gas for most saws whats the point?

 

[litefoot]

For what it's worth, I too have experimented in the past, and found that the little one gallon mix bottles of Stihl oil I measured exactly DID all seem to have a little more than the 2.8 they say if you hold the thing a while and let it all drip out. I figured this was simply Stihl knowing that not everybody will take the time to let every drop fall, and designed it so that a quick pour would yield at least the required amount for 50:1. I no longer use the little bottles, buy standard Stihl mix oil by the quart and mix 40:1 for my 60cc and under saws, and 32:1 for my 395 and MS460

That's good info that I was not aware of. Thanks!:biggrinbounce2:

 

[vegaome]

Howdy Folks,
I normally have been mixing 50:1 one gallon at a time. The only reason I mixed up 12 ounces was because I was working on a neighbors saw MAC 10-10 that he said mix at 40:1. I got it all back together and just mixed up the small amount to see if it would run.

I do think I will mix two pouches of OPTI-2 and try that. All in all though you are right when mixing in small quanities it would be pretty easy to mess up the ratio.

Thanks everyone for the feedback.

v/r

Mike

 

[scottr]

0.240 oz.

I guess but a teaspoon is still 0.17 oz even with a messuring spoon which was 1/2 a teaspoon at 0.085 oz it is still very hard to get to 0.240 oz within 0.02 oz. (1.4 teaspoons for a 50:1 ratio) and To get that accurate you would need a medicine droper in CCs or mLs (6.8 cc of oil for a 50:1 ratio). And even then, by time you account for the oil that sticks to the dropper you can still be off quite a bit in a small batch mixture.

Again that small of a mixture is less than a tank of gas for most saws whats the point?

JUDGE1162 , if you put two teaspoons of oil in 16 ounces of gas it would be a 48:1 fuelil mix . Do you think that would work ?

 

[JUDGE1162]

JUDGE1162 , if you put two teaspoons of oil in 16 ounces of gas it would be a 48:1 fuelil mix . Do you think that would work ?

I Never said it would not work, but whats the point? Scott you sort of proved my point you increased the amount of gas used by 30%, it is always easier to mix a larger batch. pretty much any size batch can be done, hell you can add 1/2 tea spoon (measuring spoon not estimated) to 4.25 oz (1/2 a cup) of gas and get a 50:1 ratio so it can be done but it is easy to screw up.

My point was not that it was impossible to mix small batches of gas but that you need to be careful because you are adding such a small amount of oil that even the smallest amount off will make a huge diffrence to your ratio. And in some case to get a true ratio you need special mesuring equipment, using a tea spoon is fine but there will be a certain amount of "film" left on the spoon which will be missing from the mix changing the ratio, smaller the batch more the "film" matters.

With the right equipment I can mix you 1oz of gas with a 50:1 oil ratio, in fact at my job I regularly mix samples with a 1 part per million ratio in a 1oz sample That is 0.00003 CCs of oil per 1 oz of gas, so it is possible but requires special equipment and equations.

 

[scottr]

Film

JUDGE1162 , if you were to stir the mix with the measuring spoon then it will not have a film .

 

[JUDGE1162]

JUDGE1162 , if you were to stir the mix with the measuring spoon then it not have a film .

Good point