2 Stroke oil Mix question

[thatguy]

Over on another forum there is a post going on 3 pages discussing how to properly mix 2 stroke oil for use in 2 stroke, air cooled engines..

2 cycle oil mix - Page 1 - AR15.COM

I wanted to get your wisdom/thoughts on the idea.

The basic concept of discussion is one of two things..

1) Mix the oil/gas the per the package labeling and that mix is good for any 2 stroke machine (doesnt matter if the engine mfg says to run 32:1, 40:1, or 50:1). the idea is that the correct oil/gas ratio is not engine specific but set by the oil mfg, and adequate for lubrication for any engines..

the other belief is..

2) You must mix the oil only to what the engine mfg says (ie - if you have 3 engines and they all call for different ratios - you need to have 3 different gas cans, one for each ratio)

thoughts?

Brian

 

[hizoot]

I'm 54 yrs old. I've raced 2 strokes motorcycles since 1967. I still have a KTM 300 .When I was younger I raced motocross and that type of racing is basically a drag race from turn to turn (full throttle). We used 32:1 mixture ratio.

As I got older,I started racing more tight woods enduro and grand national cross country. The tighter the course,meant more finesse with the throttle and lower throttle openings. We used 45-50:1 ratio. If we didnt the engine would load up with too much oil and blubber and spew all kinds of black soot.

Rebuilding these bikes over the years taught me that oil/type does make a big difference as well. Jetting,air fuel ratio of the carb is a huge deal as well. The more oil,the leaner the mixture ...but the ritcher the oil is. The reason why its leaner with more oil is that the oil takes up part of the space of the gasoline.....the more oil,the less gas in any given air/fuel ratio. So the carb must be adjusted accordingly.

 

[Carl_NH]

I have a Husky saw 55 rancher, a Stihl 400 BP blower/fogger, and Echo trimmer and use one mix for all. Usually 40/42-1 and this seems to work well for all of them.

When I put too much oil in one time (30-1) the Stihl was much harder to start and smoked more. Lesson learned..

I run a season/summer on the same 16oz oil mix and try to stay with one brand.

 

[yomax4]

Also a good synthetic oil will help bridge the gap between motors with different mix requirements. Seems like the newer motors require less oil than the older ones.

 

[brucew44guns]

I once owned a Homelite Super XL12 saw. I recall it being a 16:1 mix.
Now, I have 6 different saws and blowers and trimmers that are all Stihl. I use the Ultra Synthetic oil at 50:1 for all those machines. One gas can, one fuel. The oil bottles are for 2.5 gallons of gas to be added. I usually put 2.4 just to give a tadge more oiliness. No way would I run that mix in that old Homelite.
I believe that when the machine builder says to go 20:1, or 30:1 or whatever, they usually are referring to Major Oil brands, or names of product other than their own. I used Union 76 brand oil for years, in my Stihls too, but always followed the specific recommendation, I think it 25:1 with major brand stuff, never 50:1 with an oil like that. Stihl say 50":1 with "their" oil, I think that's safe with theirs, but probably not with some generic Wal-Mart cheapo brand.

 

[oldyellr]

The correct answer is use the oil recommended by the manufacturer mixed in the ratio recommended by the manufacturer. That way you can't go wrong.

 

[284 International]

The correct answer is use the oil recommended by the manufacturer mixed in the ratio recommended by the manufacturer. That way you can't go wrong.

...Jetting,air fuel ratio of the carb is a huge deal as well. The more oil,the leaner the mixture ...but the ritcher the oil is. The reason why its leaner with more oil is that the oil takes up part of the space of the gasoline.....the more oil,the less gas in any given air/fuel ratio. So the carb must be adjusted accordingly.

In my view, these are the two complementary explanations. If you're going to run a different ratio of fuel to oil in your gasoline, you should be adjusting the carburetor. If you run the manufacturer recommended oil at their ratio, you don't need to adjust the carburetor jetting. (Altitude normalizing excepted)

 

[Bird]

I know in years past, I've had a 2-cycle motorcycle, boat motors, chain saws, etc. that may have recommended different mixes, but now all I have is a Stihl string trimmer and a Mantis tiller. Both call for 50:1 mix and I use Stihl Ultra synthetic. I buy the little 2.6 oz bottles, good for one gallon of gas, since I don't use it fast enough to keep a bigger gas can for my 2-cycle gas.

 

[LD1]

I think is actually more oil specific than engine. Because all 2-strokes operate on the same principals.

Older stuff called for richer mixes of oil becasue the oil just wasnt as good back then.

Technology has improved out understanding of oils and what they do. As a result, oils (especially synthetics) have gotten MUCH better at doing their job. As a result, a 50:1 mix of new stuff will lubricate as well as a 25:1 mix of old stuff.

Personally, we buy the 50:1 mix bottles that are supposed to mux with 2.5 gallons of gas. We mix them with 2 gallons, or about a 40:1 mix and werun that in everything, old and new.:thumbsup:

 

[ultrarunner]

I think is actually more oil specific than engine. Because all 2-strokes operate on the same principals.

Older stuff called for richer mixes of oil becasue the oil just wasnt as good back then.

Technology has improved out understanding of oils and what they do. As a result, oils (especially synthetics) have gotten MUCH better at doing their job. As a result, a 50:1 mix of new stuff will lubricate as well as a 25:1 mix of old stuff.

Personally, we buy the 50:1 mix bottles that are supposed to mux with 2.5 gallons of gas. We mix them with 2 gallons, or about a 40:1 mix and werun that in everything, old and new.:thumbsup:

My saw guy also recommends more than less... he said 40 to 1 is the way he runs all his personal equipment...

I've got some old stuff that is 16 to 1. Seldom run it... when I do, I go 16 to 1