I have a few two-stroke lawn equipment tools that use different gas/oil ratios. What is it in the design of a two-stroke engine that requires a certain ratio? Is it the compression ratio? I googled around but couldn't find a good explanation on why the weed whip needs 50-1 and the chain saw needs 40-1.

Paul

On Saturday, March 26, 2016 at 8:57:33 AM UTC-5, Pavel314 wrote:
I have a few two-stroke lawn equipment tools that use different gas/oil ratios. What is it in the design of a two-stroke engine that requires a certain ratio? Is it the compression ratio? I googled around but couldn't find a good explanation on why the weed whip needs 50-1 and the chain saw needs 40-1.

Paul

It must have to do with design tolerance or materials used...unless you have an old 2-cycle where the oil additives were not as good as today. If you only have those 2 mixes...go with the 40:1 on both.

On 3/26/2016 9:57 AM, Pavel314 wrote:
I have a few two-stroke lawn equipment tools
that use different gas/oil ratios. What is it
in the design of a two-stroke engine that
requires a certain ratio? Is it the compression
ratio? I googled around but couldn't find a good
explanation on why the weed whip needs 50-1 and
the chain saw needs 40-1.

Paul


When I took a small engine course years ago, I asked
the same question. The teacher said the engines are
not at all fussy. As for me, I run 32:1 in everything.
Figure I'd rather run rich than lean. Lawnboy likes
to use the special non smoking oil or some such thing.
I've not tried a Lawnboy engine for anything, not sure
it's needed there either.

I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Saturday, March 26, 2016 at 11:10:59 AM UTC-4, Stormin Mormon wrote:
On 3/26/2016 9:57 AM, Pavel314 wrote:
I have a few two-stroke lawn equipment tools
that use different gas/oil ratios. What is it
in the design of a two-stroke engine that
requires a certain ratio? Is it the compression
ratio? I googled around but couldn't find a good
explanation on why the weed whip needs 50-1 and
the chain saw needs 40-1.

Paul


When I took a small engine course years ago, I asked
the same question. The teacher said the engines are
not at all fussy. As for me, I run 32:1 in everything.
Figure I'd rather run rich than lean. Lawnboy likes
to use the special non smoking oil or some such thing.
I've not tried a Lawnboy engine for anything, not sure
it's needed there either.

I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.


IDK either, but I think there is a trend over time, no?
That new engines use less oil? Are there still new engines
that use 32:1?, etc. Less would be better to reduce emissions.
And the new oils are better, synthetic, so less can be used.

On 3/26/2016 11:34 AM, trader_4 wrote:
On Saturday, March 26, 2016 at 11:10:59 AM UTC-4, Stormin Mormon wrote:
I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.


IDK either, but I think there is a trend over time, no?
That new engines use less oil? Are there still new engines
that use 32:1?, etc. Less would be better to reduce emissions.
And the new oils are better, synthetic, so less can be used.


I've heard some of the new synthetic oils run
100:1, but not sure I'd trust that lean a mix.


--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On 3/26/2016 11:10 AM, Stormin Mormon wrote:
On 3/26/2016 9:57 AM, Pavel314 wrote:
I have a few two-stroke lawn equipment tools
that use different gas/oil ratios. What is it
in the design of a two-stroke engine that
requires a certain ratio? Is it the compression
ratio? I googled around but couldn't find a good
explanation on why the weed whip needs 50-1 and
the chain saw needs 40-1.

Paul


When I took a small engine course years ago, I asked
the same question. The teacher said the engines are
not at all fussy. As for me, I run 32:1 in everything.
Figure I'd rather run rich than lean. Lawnboy likes
to use the special non smoking oil or some such thing.
I've not tried a Lawnboy engine for anything, not sure
it's needed there either.

I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.

My two cycle Lawnboys were finicky about using oil other than theirs so
that is all I used.

I'd use their stuff and ratio in chain saw and week wacker without problem.

On Sat, 26 Mar 2016 06:57:28 -0700 (PDT), Pavel314
wrote:

I have a few two-stroke lawn equipment tools that use different gas/oil ratios. What is it in the design of a two-stroke engine that requires a certain ratio? Is it the compression ratio? I googled around but couldn't find a good explanation on why the weed whip needs 50-1 and the chain saw needs 40-1.

Paul
The saw is likely older, and works harder. The "older" relates to the
oils available at the time of manufacture. I'd likely use 50:1 oil
mixed at 45:1 for both as a matter of expediency.

Don't use oil designed for 40:1 at 50:1

On Sat, 26 Mar 2016 12:40:02 -0400, Stormin Mormon
wrote:

On 3/26/2016 11:34 AM, trader_4 wrote:
On Saturday, March 26, 2016 at 11:10:59 AM UTC-4, Stormin Mormon wrote:
I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.


IDK either, but I think there is a trend over time, no?
That new engines use less oil? Are there still new engines
that use 32:1?, etc. Less would be better to reduce emissions.
And the new oils are better, synthetic, so less can be used.


I've heard some of the new synthetic oils run
100:1, but not sure I'd trust that lean a mix.
Several of the 100:1 synthetics have been "recalled/relabelled: with
cautions not to use beyond 50:1, apparently.

On Sat, 26 Mar 2016 13:52:22 -0400, wrote:

The saw is likely older, and works harder. The "older" relates to the
oils available at the time of manufacture. I'd likely use 50:1 oil
mixed at 45:1 for both as a matter of expediency.

Don't use oil designed for 40:1 at 50:1

I've seen some of these oils that say they are good for ALL 2cycle
engines. Just add contents of the bottle to a gallon of gas (or 2
gallons, or whatever is marked on the bottle).

I've never used that stuff, buy wanted to mention it. I rarely use any
2cycle engines anymore. I replaced most of them with electric models,
such as chainsaw and weed whacker. Far less hassle getting them to
start, and having to worry about gas getting stale, and trying to run
them dry after use and all of that trouble....

However, I always believed in adding a little more oil, rather than
less. It might smoke a little, but at least it's well lubricated. If the
OP only has a 40 to 1 and a 50 to one. I'd just use the 40 to 1 in both.

On Sat, 26 Mar 2016 06:57:28 -0700 (PDT), Pavel314
wrote:

I have a few two-stroke lawn equipment tools that use different gas/oil ratios. What is it in the design of a two-stroke engine that requires a certain ratio? Is it the compression ratio? I googled around but couldn't find a good explanation on why the weed whip needs 50-1 and the chain saw needs 40-1.

Paul

If they are from the same time era, can't you spit the difference?
45:1 or not.

On Saturday, March 26, 2016 at 2:52:25 PM UTC-5, Oren wrote:
On Sat, 26 Mar 2016 06:57:28 -0700 (PDT), Pavel314
wrote:

I have a few two-stroke lawn equipment tools that use different gas/oil ratios. What is it in the design of a two-stroke engine that requires a certain ratio? Is it the compression ratio? I googled around but couldn't find a good explanation on why the weed whip needs 50-1 and the chain saw needs 40-1.

Paul

If they are from the same time era, can't you spit the difference?
45:1 or not.

He could but 40:1 in both would be safer, obviously. 45:1 wouldn't be recommended for either...and less *safe* for the 50:1.

On 3/26/16 12:54 PM, Frank wrote:
On 3/26/2016 11:10 AM, Stormin Mormon wrote:
On 3/26/2016 9:57 AM, Pavel314 wrote:
I have a few two-stroke lawn equipment tools
that use different gas/oil ratios. What is it
in the design of a two-stroke engine that
requires a certain ratio? Is it the compression
ratio? I googled around but couldn't find a good
explanation on why the weed whip needs 50-1 and
the chain saw needs 40-1.

Paul


When I took a small engine course years ago, I asked
the same question. The teacher said the engines are
not at all fussy. As for me, I run 32:1 in everything.
Figure I'd rather run rich than lean. Lawnboy likes
to use the special non smoking oil or some such thing.
I've not tried a Lawnboy engine for anything, not sure
it's needed there either.

I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.

My two cycle Lawnboys were finicky about using oil other than theirs so
that is all I used.

I'd use their stuff and ratio in chain saw and week wacker without problem.

Echo says the mix oil used in their 2 cycle engines has to meet JASO FD,
ISO-L-EGD specs or the warranty is void. Their (pretty expensive) brand
of oil does-- but so do some generics and other less expensive brands.

--
“Let the one who has no sword sell his cloak and buy one.”
- Jesus (Luke 22:36)

On 3/26/2016 6:31 PM, Wade Garrett wrote:
On 3/26/16 12:54 PM, Frank wrote:
On 3/26/2016 11:10 AM, Stormin Mormon wrote:
On 3/26/2016 9:57 AM, Pavel314 wrote:
I have a few two-stroke lawn equipment tools
that use different gas/oil ratios. What is it
in the design of a two-stroke engine that
requires a certain ratio? Is it the compression
ratio? I googled around but couldn't find a good
explanation on why the weed whip needs 50-1 and
the chain saw needs 40-1.

Paul


When I took a small engine course years ago, I asked
the same question. The teacher said the engines are
not at all fussy. As for me, I run 32:1 in everything.
Figure I'd rather run rich than lean. Lawnboy likes
to use the special non smoking oil or some such thing.
I've not tried a Lawnboy engine for anything, not sure
it's needed there either.

I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.

My two cycle Lawnboys were finicky about using oil other than theirs so
that is all I used.

I'd use their stuff and ratio in chain saw and week wacker without
problem.

Echo says the mix oil used in their 2 cycle engines has to meet JASO FD,
ISO-L-EGD specs or the warranty is void. Their (pretty expensive) brand
of oil does-- but so do some generics and other less expensive brands.


Don't recall what I was using but shop told me that it was reason I was
having problems that I brought to them. I did not want to inventory
different mixes so used the same in all. I had two Lawnboys, neither of
which would start one spring so I traded them both in for a 4 cycle Honda.

On Sat, 26 Mar 2016 18:31:38 -0400, Wade Garrett
wrote:

“Let the one who has no sword sell his cloak and buy one.”
- Jesus (Luke 22:36)

AMEN

Arm yourself.

On Sat, 26 Mar 2016 13:37:16 -0700 (PDT), bob_villain
wrote:

On Saturday, March 26, 2016 at 2:52:25 PM UTC-5, Oren wrote:
On Sat, 26 Mar 2016 06:57:28 -0700 (PDT), Pavel314
wrote:

I have a few two-stroke lawn equipment tools that use different gas/oil ratios. What is it in the design of a two-stroke engine that requires a certain ratio? Is it the compression ratio? I googled around but couldn't find a good explanation on why the weed whip needs 50-1 and the chain saw needs 40-1.

Paul

If they are from the same time era, can't you spit the difference?
45:1 or not.

He could but 40:1 in both would be safer, obviously. 45:1 wouldn't be recommended for either...and less *safe* for the 50:1.
Actually safer for the 50:1. More oil than spec.

On 3/26/2016 5:44 PM, Frank wrote:
On 3/26/2016 6:31 PM, Wade Garrett wrote:
On 3/26/16 12:54 PM, Frank wrote:
On 3/26/2016 11:10 AM, Stormin Mormon wrote:
On 3/26/2016 9:57 AM, Pavel314 wrote:
I have a few two-stroke lawn equipment tools
that use different gas/oil ratios. What is it
in the design of a two-stroke engine that
requires a certain ratio? Is it the compression
ratio? I googled around but couldn't find a good
explanation on why the weed whip needs 50-1 and
the chain saw needs 40-1.

Paul


When I took a small engine course years ago, I asked
the same question. The teacher said the engines are
not at all fussy. As for me, I run 32:1 in everything.
Figure I'd rather run rich than lean. Lawnboy likes
to use the special non smoking oil or some such thing.
I've not tried a Lawnboy engine for anything, not sure
it's needed there either.

I suspect the difference in ratio is based on the
machining and manufacturing -- hard versus soft
steel for example.

My two cycle Lawnboys were finicky about using oil other than theirs so
that is all I used.

I'd use their stuff and ratio in chain saw and week wacker without
problem.

Echo says the mix oil used in their 2 cycle engines has to meet JASO FD,
ISO-L-EGD specs or the warranty is void. Their (pretty expensive) brand
of oil does-- but so do some generics and other less expensive brands.


Don't recall what I was using but shop told me that it was reason I was
having problems that I brought to them. I did not want to inventory
different mixes so used the same in all. I had two Lawnboys, neither of
which would start one spring so I traded them both in for a 4 cycle Honda.

Echo also states in their manual:

Echo premium Power Blend X TM Universal 2-Stroke Oil may be mixed at
50:1 ratio for application in all Echo engines sold in the past
regardless of ratio specified in those manuals.

Small engine shop I use said that if I use the pre-mixed fuel (no
alcohol) I can use the 50:1 mix across the board and all will be well.

On Saturday, March 26, 2016 at 8:28:28 PM UTC-5, wrote:
On Sat, 26 Mar 2016 13:37:16 -0700 (PDT), bob_villain
wrote:

On Saturday, March 26, 2016 at 2:52:25 PM UTC-5, Oren wrote:
On Sat, 26 Mar 2016 06:57:28 -0700 (PDT), Pavel314
wrote:

I have a few two-stroke lawn equipment tools that use different gas/oil ratios. What is it in the design of a two-stroke engine that requires a certain ratio? Is it the compression ratio? I googled around but couldn't find a good explanation on why the weed whip needs 50-1 and the chain saw needs 40-1.

Paul

If they are from the same time era, can't you spit the difference?
45:1 or not.

He could but 40:1 in both would be safer, obviously. 45:1 wouldn't be recommended for either...and less *safe* for the 50:1.
Actually safer for the 50:1. More oil than spec.

....good to have you here to correct the feeble minded!