2 Stroke engine oil mix

   / 2 Stroke engine oil mix #1  

Hans

New member
Joined
May 17, 2002
Messages
23
Location
Texas
Tractor
Kubota L3300 GST/L481
How important do you think it is to use the exact mix ratio for a two stroke engine. The reason I ask is I have 3 Stihls (50:1), 2 McCulloch's(40:1) and 1 IDS(recommended 32:1, although the owner's manual says 40:1 is ok) . I have started buying only one brand (Stihl) to avoid this problem but the older equipment is still working ok. If I run 50:1 in a product rated for 32:1 am I just shortening its piston life span by 50% or is it going to seize after 2 tanks of gas. I've never known anyone who used a two stroke engine enough to wear out a piston; something like a carb or such usually seems to die first and ends up being more of a pain to fix than just buying another unit.
 
   / 2 Stroke engine oil mix #2  
I don't think it's that important. The old 2 cycles recommended 16:1. My old Poulan chain saw is supposed to get 16:1 but I've fed it a steady diet of 32:1 to 50:1 for at least the last 10 years and it still runs fine. BTW, a chain saw is a much heavier duty application than, say, a string trimmer or a 2 cycle lawn mower. I would think if anything would crap out from a thin gas/oil mix, it would be a chain saw, and I haven't seen it. My Husky recommends 50:1 and I'm not going to keep two separate mixes around.
 
   / 2 Stroke engine oil mix #3  
Hans, just a few personal thoughts on the topic:
First, I tend to agree with cp1969 that it probably isn't too important.
The purpose of the oil in the gasoline is lubrication.
If the engine doesn't get enough lubrication, you'll ruin it and the manufacturer knows it so they may sometimes recommend a little more oil than is really necessary.
A little too much oil probably doesn't hurt anything except foul plugs more quickly, build up carbon in the engine and/or on the spark arrestor in the muffler.
Some of the older 2 stroke engine recommendations were based on "outboard motor oil."
Some of the newer 2 stroke oils, designed specifically for air cooled engines instead of outboards, supposedly provide good lubrication in smaller quantities.

So . . ., you only want to buy the one brand. In my opinion (and I'm no chemist) there should be no problem. If in doubt, mix it just a little bit stronger (not much) than the label calls for, and plan to change spark plugs a little more frequently.
 
   / 2 Stroke engine oil mix #4  
Hans,
Go with a happy medium,mix them all at 40:1 should work out fine..
 
   / 2 Stroke engine oil mix #5  
While running in, my outboard called for 25:1. Now after that, is uses 50:1.

I always err on the high side. Figuring fouled plugs are better than noisy bits inside !!!
 
   / 2 Stroke engine oil mix #6  
Hans,

It's about 32-40-1 ratio pending how accurate your are measuring the gas. I filled up my mix can (2 gal) once with a one gallon milk container and marked the level and add 3.5 -4 oz oil per gallon. I run a Husky 51 saw, a Sthil 420 blower, a Komatsu Leaf blower, Stihl 3000 saw, and Ryobi trimmer cultivator on the same mix. I have used the same 2 cycle oil the last 10 yrs - made by Drydene, now Castrol. (my brother in law works for them so I have a good supply) Only failure I have had is a homelite brush trimmer bought in 82 lost power and compression in 99, 17 years I guess is OK..

Carl
 
   / 2 Stroke engine oil mix #7  
I only have two 2 cycle engines one uses 32:1 and the other 42:1. Last year I purchased a 100:1 oil mix from Amsoil. The label claimed you could use this oil safely at a rate of 100:1 for all 2 cycle gas engines. Cost about $6.00/quart.

I've been using it at 42:1 in my 32:1 engine ( an old chain saw ) with I guess 10 tanks of gas/oil. I've seen no known ill effects.

For a multi. ratio person like you I saw a new product in the WWW.countryhomeproducts.com site. These are the DR Trimer people.

The new product looks like a gas can with a smaller tank attached. Connecting both the small tank and the gas tank is a tube with an automatic mixing valve. The mixing valve has a dial to set the ratio you want. Just dial and pour. The cost is $37.95.
 
   / 2 Stroke engine oil mix #8  
There are several important things about 2 cycle oil mixes.

1. Always use a chainsaw oil in a chainsaw or anything that has a similar engine like a weedwacker. Stick with a manufacturer's brand of oil such as Stihl, Husky, or any other major brand.

2. NEVER use outboard motor oil in a chainsaw. Outboard motor oil is not formulated to operate in air cooled 2 cycle engines. Outboards are water cooled engines and they run much cooler than a chainsaw. The same is true for motorcycle oils.

3. Never use gas that has been mixed for longer than a month. The lubricating porperties of the oil break down in the gas the longer it sits unused. It is less expensive to mix a new batch than it is to fix an engine that didn't get proper lubrication.

I have two different mix ratio chainsaws, 32:1 and 40:1. I feed them both about a 40:1 mix. I buy the little bottles of oil that mix with a gallon of gas and mix a gallon at a time. Some days I use most of the gallon of fuel, but I don't mind mixing a new batch the next day.

I think it cost less than $3.00 for a gallon of mixed fuel I don't mind not using a portion of that, that is far less than the $600.00 I paid for just one saw.

Randy
 
   / 2 Stroke engine oil mix #9  
I, too, have read that you should not use mixed gas if it's over a month old.

But I can't count the number of times that I've done exactly that (with gas MUCH older than one month) and I'm still waiting to have my first 2 cycle engine failure, and I am no spring chicken.
 
   / 2 Stroke engine oil mix #10  
I understand the reason not to use gas mix that is old, but what else can you do with it?? I don't want to dump it on the ground. /w3tcompact/icons/hmm.gif
 
 
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