Two Ccyle Gas Mixtures: Meaningful Differences Between 40 and 50 to 1 ?

[Robert11]

Hello:

Have a collection now of 2-Cycle garden stuff like weed wackers, leaf blowers, etc.

Some are older, some are new.

There is a divergence of requirements on the oil-gas mix for them. Some say 40 to 1, some are 50 to 1.

Realize the best is to go by the manuals, of course, but it's a real pain keeping different gas mixtures.

Any "real" and meaningful differences if I use just one ratio mix in all ?

If so, which would be better ?

Thanks, B.

[Pete C.]

I'd shoot for 40:1 with a quality brand of oil (not the cheapest you can find) and be done with it. Worst case should be perhaps a tiny bit more smoke from some of the engines, but it shouldn't hurt anything unless you're in CA perhaps and have the CARB Nazis after you.

Pete C.

[m Ransley]

32-1 is great for long life but what your unit recomends is how it is tuned to run, often a richer mix cant be made to start well as many units have the adjusting screws locked. The Epa wants less oil, less polution, but you sacrifice engine life. There was a point Evenrude went to lean to apease the EPA and engines started seizing, their 2-3000$ motors. Another better alternative is synthetic 2 stroke oil. Yamaha should have one as does Mobil make a 2 stroke synthetic mix. I just use 32-1 and synthetic when I find it, my Echos start hard but run well. Synthetics by manufacturer admissions allow a leaner mix.

[Mys Terry]

You would think that more oil would be better for the engine, but it's not. More oil in the mix lowers combustion chamber temps and causes excessive carbon buildup, and potentially stuck and cracked rings. Most two-strokes in modern small yard equipment are perfectly happy using 50:1 as long as you use a good quality oil.

[The Reverend Natural Light]

The air/fuel mixture is adjusted to work with the oil mixture. Some people think they're doing an engine a favor by using more oil, but what that does is reduce the amount of fuel causing a lean mixture and too much heat.

Most of my 2-stroke motorcycles have always taken a 32:1 mix, thus I always have a can of it around. The weed wacker got whatever was in that can and was always happy with it.

Now I have a new Stihl trimmer. It cost enough that I'm not taking any chances. It has it's own gas can mixed with the pre-measured oil bottles supplied by the dealer. And, it has a catalytic converter which is a whole new issue.

Anyways, if you're dealing with a collection of equipment that ranges from 40:1 to 50:1, just average it out and mix one can for everything. Be sure the oil is rated to that ratio. If you don't already own a Ratio-Rite then go to a motorcycle shop and get one.

-rev

Robert11 wrote:

[RW]

Your trimmer has a catalytic converter? Does it have a check engine light as well? Need to take it in for Echeck yearly? (shakes head)

[JD]

[rdglide03-dbasedos]