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FarmerCharlie
05-20-2011, 01:02 PM
Does anyone have a general recommendation for the gas/oil mixtures for various engines? The recommended oils and ratios vary from about 20:1 for my old 1950s era Elgin outboard through 40:1 for my Husky chain saw to 50:1 for my new Shindaiwa C4 trimmer. In the past I just settled on the 40:1 Husky oil for everything (except the old outboard), and I wonder if there is any strong reason to change from that.
Thanks,
Charlie

RAlmaroad
05-20-2011, 02:52 PM
Charlie:
Is missing something here? Each manufacturer of an engine has tested their product and has established which ratio of gas to oil to use. You should go by their recommendation else you could burn up your plug or engine piston or cylinder wall with too lean of a mixture. As to reasons each motor has a thickness of the critical heated parts which are tested as to air cooled fins, speed of engine, all sorts of variables which they know about. If you had 5 different machine; each requiring as stated in the manual to use a ratio then you'd need 5 different mixes--just label each one. Better yet, if you stay with one manufacturer such as Stihl then most of their engines would generally have the same mix. Remember way back in the 60's how those big cars with 454 carbed motors needed only super leaded octane gas to run? They would run on today's gas for the same reason. Sure they might spit and sputter but would run properly on their intended gas. I know very little about the workings of gas engines but am sure there are reason for the recommended ratio. Go by the manual.

32vld
05-20-2011, 10:15 PM
You want a recommendation?

Follow the manufacturers recomendation.

Km81
05-21-2011, 08:13 AM
All my equipment requires 50:1 and I only use Stihl Ultra 2 cycle oil. It make everything run a lot smoother, and its only .30 cents more than the cheap crap.

Smallaxe
05-21-2011, 08:41 AM
They have a "Universal Mix" that covers all ratio combinations and it is a 'quality' oil.

The biggest problem people have with 2 cycle engines is the use of 'cheap oil', then it's cheap gas, and if you're going to use the ethanol 87 Octane, forget it...

If you don't trust the universal mix at least use premium gasoline and quality oil mix...

Humbertslawncare
05-21-2011, 05:26 PM
Not to trying to take this post or anything, but this question does deal with the OP's question. If your bottle of oil for 2 cycle is for 2 gallons of gas, do you add exactly 2 gallons or do you use a little less gas?

cgaengineer
05-21-2011, 06:49 PM
Not to trying to take this post or anything, but this question does deal with the OP's question. If your bottle of oil for 2 cycle is for 2 gallons of gas, do you add exactly 2 gallons or do you use a little less gas?

Its not that critical.
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24brookside
05-22-2011, 05:08 AM
I am pretty sure the epa has something to do with those weak ratio recommendations.

50:1 or 32:1...hmmmm now lets see. 32:1 is like 30 % +- more engine lubricant.
Someone who tells you to run 50:1 or even 40:1 is not your friend or just does not know. I have seen a million stihl pieces laying around landscapers shops with the head pulled off and a scorched piston because they followed the epa/manufactures recommendations.

1 can lawn-boy oil (8 oz) to 2 gal gas. (32:1) Like religion. Never a problem. never change the spark plug.

I run my 2 stroke dirt bikes 24:1

Just my .02

RAlmaroad
05-22-2011, 06:29 AM
Important for everyone: About a year ago there was a big report with several repair shops for chainsaws, lawnmowers and weed eaters helping. The findings were that so many of the plastic lines were being melted by "Ethanol". Their recommendation was to use pure non ethanol gas. Most everyone in East TN use non-ethanol in their chainsaw, weedeater and lawnmowers. I had to take a Husky weedeater before the report came out; when I saw the repaired part--it was melted as the report mechanics said. Non ethanol gas is higher but not as high as a repair cost and you won't find it in the recommendations in the manual. A few words or a chance to sell another machine or engine part--think about it.

FarmerCharlie
05-22-2011, 09:22 PM
Thanks for the comments. As I expected, the opinions on this subject are not unanimous. I do use ethanol-free gas in all my equipment--mainly because some equipment may sit for a pretty long time between uses. But there is just one dealer left in my area that carries it; one went out of business, and the second quit carrying it. I guess I'll keep using the brand name 40:1 oils, and maybe back off a little on the amount of gas I add.

Km81
05-22-2011, 09:39 PM
I am pretty sure the epa has something to do with those weak ratio recommendations.

50:1 or 32:1...hmmmm now lets see. 32:1 is like 30 % +- more engine lubricant.
Someone who tells you to run 50:1 or even 40:1 is not your friend or just does not know. I have seen a million stihl pieces laying around landscapers shops with the head pulled off and a scorched piston because they followed the epa/manufactures recommendations.

1 can lawn-boy oil (8 oz) to 2 gal gas. (32:1) Like religion. Never a problem. never change the spark plug.

I run my 2 stroke dirt bikes 24:1

Just my .02

Stihl has recommended 50:1 in all of their equipment for as far back as I can remember. I have never heard of any Stihl engines failing due to lack of lubrication.
32:1 makes the mixture a bit too thick, and you will lose throttle response as well as low end torque because the engine cant burn the oil as fast. These machines operate at extremely high rpm and they need the most efficient mixture possible to do so.
So in the end: Follow your manufacturers recommended mix on all your equipment.

cgaengineer
05-23-2011, 09:13 AM
50:1 in a 25 year old Stihl chainsaw and she still runs great.
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GrandMaster
05-25-2011, 01:48 AM
I am pretty sure the epa has something to do with those weak ratio recommendations.

50:1 or 32:1...hmmmm now lets see. 32:1 is like 30 % +- more engine lubricant.
Someone who tells you to run 50:1 or even 40:1 is not your friend or just does not know. I have seen a million stihl pieces laying around landscapers shops with the head pulled off and a scorched piston because they followed the epa/manufactures recommendations.

1 can lawn-boy oil (8 oz) to 2 gal gas. (32:1) Like religion. Never a problem. never change the spark plug.

I run my 2 stroke dirt bikes 24:1

Just my .02

LOL! they probally feel like a 125 than!

Any motor will run best with leaner high octane fuel. (good oil only)

I run 50:1 in everything dirt bikes to trimmers. Only when new Ill run 40:1 for break in.

2 strokes are built for the heat cheap oil is the problem or not precise mixes as not all oil is the same rate. Some of my maxima oils are 2.6oz per gal and my others are 2.8 etc.

Richard Martin
05-25-2011, 06:22 PM
Hey, look who showed up to the party...

I've been using Amsoil mixed at 80:1 with a high quality mid grade gas for at least 10 years. In all of those 10 years I have not had one single oil related failure or breakdown. I use Shell 10% ethanol gas. I do have to replace the fuel lines and primer bulb every few years. I just retired a Stihl BR600 that I bought in 2005. It's not worn out. I just felt like buying a new one and have the old one as a backup. I put exactly 1 sparkplug in it through all of it's years.

snow4me
05-26-2011, 12:24 AM
Hey, look who showed up to the party...

I've been using Amsoil mixed at 80:1 with a high quality mid grade gas for at least 10 years. In all of those 10 years I have not had one single oil related failure or breakdown. I use Shell 10% ethanol gas. I do have to replace the fuel lines and primer bulb every few years. I just retired a Stihl BR600 that I bought in 2005. It's not worn out. I just felt like buying a new one and have the old one as a backup. I put exactly 1 sparkplug in it through all of it's years.

I've been using 91 octane and Amsoil Synthetic premix at 100:1 without a problem.

Stillwater
05-26-2011, 12:52 AM
my dynadigger takes 100 1

bmc1025
05-26-2011, 11:00 PM
I would just use 40:1 in everything it wont hurt the 50:1 motor, or foul the plug. The tolerances are not the reason for the 50:1 mix it is the EPA, luckily modern 2-stroke oils are of good quality and can protect in thinner ratios.

That being said I use mercury boat motor oil mixed 50:1 in everything, it is a very clean burning oil. The tops of the pistons and exhaust ports are always clean when I pull the plug or muffler.