mixing gas and oil questions
 

You can do a test yourself. Place a drop of gasoline down the barrel of a daisy BB gun and fire it....no effect. Use a drop of oil
and you will hear the detonation when the lube oil detonates. Further, try running a diesel engine on high octane gasoline and see
what doesn't happen. You may be able to move to 50:1 from 100:1.....maybe, but modern two stroke engines use a lot more
compression than the older ones and when using too much oil in the mix, you will melt a piston.
Steve

"Flying Pig" wrote in message ...
"Steve Lusardi" wrote in message ...
Ted,
Adding lube oil to gasoline lowers the flash point of the fuel increasing the chance of detonation. Oil in the fuel is
necessary for these type of engines, but NEVER use more than the manufacturer's recommendation. Failure to follow this simple
direction could melt the pistons, the heads and effectively ruin the engine and I have seen this hundreds of times. I know this
is counter intuitive, hence the number of times this failure occurs.
Steve


Interesting. The Outboard Shop, the local evinrude/johnson dealer, gave me the exact opposite recommendation. The question came
up with my newer engine which is designed to run on 100-1 mix. They told me it will run just fine on the same stuff as my older
engine, a 50-1 mix. They also cautioned me that the least "too-little" mix , such as missing by a bit when filling from a
not-empty supply and having to guess at the right amount, could turn it into an anchor. Failure to use enough deprives the
engine of its lubrication, and things seize up.

Further, my manuals for both engines show to use double the oil in severe use conditions. I.e., in the newer one, 50-1, in the
older one, 25-1. More oil, at least as inferred from the manuals, assures that won't happen, even if you overdo it.

I grant you that quadrupling the oil may have some deletorious effects, but my common sense tells me that 16% more than
specified as ADEQUATE should not be a problem.

Also, I've never seen oil being more subject to explosion/flash than gasoline. How does adding oil to fuel make it more
volatile?

L8R

Skip

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mixing gas and oil questions
 

Engine repair shops love customers like you....you keep them in business.
Steve

"jamesgangnc" wrote in message ...
On Oct 25, 12:02 pm, ted@theted. wrote:
i have a jetski and a boat with an evinrude 115 hp outboard. can
they both use the same gas/oil mix? someone told me it should be
a pint to six gallons but i would rather mix a pint with 5
gallons because it's easier and to be on the safe side if that's
ok. is a pint to 5 gallons ok for both the jetski and the
evinrude?

thanks!

ted

I only have smaller 2 strokes and one jetski. The jetski mixes it's
self with a oil pump to the carbs. But I mix the same ratio for all
my small engines without any problems.

mixing gas and oil questions
 

"Ron" wrote in message
...
On Mon, 25 Oct 2010 14:23:46 -0400, I am Tosk
wrote:

In article 29b625b4-9ffe-4736-b512-dff137d6aa81
, says...


haven't figured out what it was, but I shipped it:


Also, I've never seen oil being more subject to explosion/flash than
gasoline.

How does adding oil to fuel make it more volatile?
L8R
Skip

Your comment and question shows a basic lack of fuel and combustion
concept understanding.

Yeah, I gathered he isn't a internal combustion engineer so what's your
point? I worked on cars for a long time and really never thought about
ping as it relates to two stroke fuel/oil mix, I just mix it right;) and
with the octane we run, ping is not really an issue.. As to why the high
mixture and why it would cause ping, I have some ideas, but really, I
don't think it's all that important as long as I have a measuring cup...

That being said in my lawn equipment and boats I run regular fuel with
Spectro32:1 which is designed to run at that mixture in most two stroke
engines.. It's universal.


No it isn't! Water cooled outboards run at much lower temps than air
cooled lawn equipment. The requirements for the oil are quite
different.

And 32:1 will cause an engine that is designed for 50:1 to run lean.
Not good!




It's apparent you don't understand what the ration you used means.

32:1 means 32 parts gasoline to one part oil
50:1 means 50 parts gasoline to one part oil

Therefore, you are wrong to say 32:1 will burn leaner than 50:1. Fifty to
one burns leaner by virtue of the fact that there is more gasoline to burn
and less oil.

A richer oil/gasoline ratio (more oil to gas as in 32:1) will cause a
two-stroke engine to run richer - not leaner. Oil also burns (most of it)
but oil burns less easily and more slowly (under the compression ratios
present in gasoline engines) because it's less combustible than gasoline. It
takes a high compression, diesel engine to burn oil efficiently. It ain't
gonna happen efficiently in a gasoline engine because of the low compression
ratios


Wilbur Hubbard

mixing gas and oil questions
 

On Mon, 25 Oct 2010 11:46:00 -0700 (PDT), jamesgangnc
wrote:

On Oct 25, 12:02*pm, ted@theted. wrote:
i have a jetski and a boat with an evinrude 115 hp outboard. can
they both use the same gas/oil mix? someone told me it should be
a pint to six gallons but i would rather mix a pint with 5
gallons because it's easier and to be on the safe side if that's
ok. is a pint to 5 gallons ok for both the jetski and the
evinrude?

thanks!

ted

I only have smaller 2 strokes and one jetski. The jetski mixes it's
self with a oil pump to the carbs.

the guy who was working on it suggested that i have the pump mix
system removed for a couple of reasons. one was because it was
smoking badly meaning it was mixing too much oil, and the other
was because somewhere in that system it was leaking oil into the
hull. he said it could just as easily mix too little as mix too
much and that would ruin the engine, so i figured after getting
lucky and having a second chance it was best to have the messy
threat removed so it won't ever be an issue again.

But I mix the same ratio for all
my small engines without any problems.

what ratio?

mixing gas and oil questions
 

On Mon, 25 Oct 2010 13:13:49 -0400, "Flying Pig"
wrote:

"Steve Lusardi" wrote in message
...
Ted,
Adding lube oil to gasoline lowers the flash point of the fuel increasing
the chance of detonation. Oil in the fuel is necessary for these type of
engines, but NEVER use more than the manufacturer's recommendation.
Failure to follow this simple direction could melt the pistons, the heads
and effectively ruin the engine and I have seen this hundreds of times. I
know this is counter intuitive, hence the number of times this failure
occurs.
Steve


Interesting. The Outboard Shop, the local evinrude/johnson dealer, gave me
the exact opposite recommendation. The question came up with my newer engine
which is designed to run on 100-1 mix. They told me it will run just fine
on the same stuff as my older engine, a 50-1 mix. They also cautioned me
that the least "too-little" mix , such as missing by a bit when filling from
a not-empty supply and having to guess at the right amount, could turn it
into an anchor. Failure to use enough deprives the engine of its
lubrication, and things seize up.

when the evinrude was re-built the mechanic told me to mix 50-1
instead of the regular 25-1 until it got broken in. when i asked
if it would hurt to keep mixing it that way all the time he said
no.

Further, my manuals for both engines show to use double the oil in severe
use conditions. I.e., in the newer one, 50-1, in the older one, 25-1. More
oil, at least as inferred from the manuals, assures that won't happen, even
if you overdo it.

I grant you that quadrupling the oil may have some deletorious effects, but
my common sense tells me that 16% more than specified as ADEQUATE should not
be a problem.

that mechanic and the jetski mechanic both said too much is okay
but too little will ruin the engine because what you're doing is
running it low on oil, which certainly makes sense.

Also, I've never seen oil being more subject to explosion/flash than
gasoline. How does adding oil to fuel make it more volatile?

for real. i've been running the evinrude about 50-1 for about a
year and it hasn't blown up or even overheated. one person told
me that mixing too much oil makes it have a problem with wanting
to quit when you're trying to start it...it will fire up for a
few seconds and then die which it is doing. but he may have just
said that because he knew i was mixing it heavy on oil. he told
me that at a time when we were having the problem. it usually
only does it once or twice though, and then runs fine.

mixing gas and oil questions
 

On Mon, 25 Oct 2010 18:48:09 +0200, "Steve Lusardi"
wrote:

Ted,
Adding lube oil to gasoline lowers the flash point of the fuel increasing the chance of detonation. Oil in the fuel is necessary
for these type of engines, but NEVER use more than the manufacturer's recommendation. Failure to follow this simple direction
could melt the pistons, the heads and effectively ruin the engine and I have seen this hundreds of times.

as yet i find it hard to believe that you've seen it happen at
all, much less hundreds of times. how much more oil are you
talking about?

I know this is counter intuitive,

to say the least.

hence the number of times this failure occurs.

can you provide any reason to believe that happens a lot, other
than your own unlikely sounding claim? i've never heard of it
happening at all, and if it were as common as you say it is it
seems it's one of those things mechanics would warn people about.

ted@theted. wrote in message ...
i have a jetski and a boat with an evinrude 115 hp outboard. can
they both use the same gas/oil mix? someone told me it should be
a pint to six gallons but i would rather mix a pint with 5
gallons because it's easier and to be on the safe side if that's
ok. is a pint to 5 gallons ok for both the jetski and the
evinrude?

thanks!

ted

mixing gas and oil questions
 

ted@theted. wrote in message
...
On Mon, 25 Oct 2010 11:46:00 -0700 (PDT), jamesgangnc
wrote:

On Oct 25, 12:02 pm, ted@theted. wrote:
i have a jetski and a boat with an evinrude 115 hp outboard. can
they both use the same gas/oil mix? someone told me it should be
a pint to six gallons but i would rather mix a pint with 5
gallons because it's easier and to be on the safe side if that's
ok. is a pint to 5 gallons ok for both the jetski and the
evinrude?

thanks!

ted

I only have smaller 2 strokes and one jetski. The jetski mixes it's
self with a oil pump to the carbs.

the guy who was working on it suggested that i have the pump mix
system removed for a couple of reasons. one was because it was
smoking badly meaning it was mixing too much oil, and the other
was because somewhere in that system it was leaking oil into the
hull. he said it could just as easily mix too little as mix too
much and that would ruin the engine, so i figured after getting
lucky and having a second chance it was best to have the messy
threat removed so it won't ever be an issue again.

But I mix the same ratio for all
my small engines without any problems.

what ratio?



Idiot! Moron. Fool. There could well be other oil feed lines than the ones
to the carbs that you see. That might be where the oil leak is coming from.
If this were the case and the oil feed was going to lubricate the crankshaft
main bearings, for example, and there were oil seals in place to separate
the bearings from the crankcase to better facilitate secondary compression
and transfer of the fuel/oil mix, the main bearings, having no source of
lubrication, (the fuel/oil mixture couldn't get to the bearings because of
the seals) would quickly overheat and fail. your mechanic is not to be
trusted. He's stupid, ignorant or both.

Wilbur Hubbard

mixing gas and oil questions
 

On Oct 25, 2:35*pm, "Wilbur Hubbard"
wrote:
"I am Tosk" wrote in l-september.org...



In article 29b625b4-9ffe-4736-b512-dff137d6aa81
@l8g2000yql.googlegroups.com, says...

haven't figured out what it was, but I shipped it:

Also, I've never seen oil being more subject to explosion/flash than
gasoline.

How does adding oil to fuel make it more volatile?
* L8R
* Skip

Your comment and question shows a basic lack of fuel and combustion
concept understanding.

Yeah, I gathered he isn't a internal combustion engineer so what's your
point? I worked on cars for a long time and really never thought about
ping as it relates to two stroke fuel/oil mix, I just mix it right;) and
with the octane we run, ping is not really an issue.. As to why the high
mixture and why it would cause ping, I have some ideas, but really, I
don't think it's all that important as long as I have a measuring cup....

That being said in my lawn equipment and boats I run regular fuel with
Spectro32:1 which is designed to run at that mixture in most two stroke
engines.. It's universal.

Will those here more knowledgable please
inlighten SKip.

Why, all he really needs is an answer to his question, he isn't asking
for a course;)?

This is a discussion group, isn't it? So why not discuss? The OP might learn
something.

Wilbur Hubbard

Why does that man call you a sexual predator?

mixing gas and oil questions
 

On Oct 25, 11:02*am, ted@theted. wrote:
i have a jetski and a boat with an evinrude 115 hp outboard. can
they both use the same gas/oil mix? someone told me it should be
a pint to six gallons but i would rather mix a pint with 5
gallons because it's easier and to be on the safe side if that's
ok. is a pint to 5 gallons ok for both the jetski and the
evinrude?

thanks!

ted

Mix according to the engine manufacture's recommendations and use a
good quality 2-cycle oil that is rated for 'water cooled' engines.
They are designed for the heat factors which are different from weed
eaters and chainsaws.

mixing gas and oil questions
 

My 2-cents.

First, a 50-1 mix is about 2% oil; a 25-1 mix about 4%. Yes, twice as
much oil but still very little of it. Unlike Steve, I've seen many
(not his hundreds) of 2-cycle engines seize up from too little oil,
but never from too much. Heck, I remember one guy that used 12.5-1 (2
qts. in 6 gallons) in his ultralight. Looked like he had a smoke
system! BTW, the ultralight engine manufacturers recommended 25-1 for
the first 25 hours for break in.

Not water cooled, but a real world example. About 20 years ago I built
and flew a gyrocopter. It used a WW II era 90HP, 4 cylinder engine.
The manufacgturer's recommended mix was 25 parts 130 Octane leaded
aviation gas to 1 part 40 wt. aviation (mineral) oil.

The 70's did away with the two aviation grades so the choice was 100
LL ( 100 Octane low lead ) or premium auto gas.

Most everyone also used 2-cycle oil and mixed it 50-1 because it's
mainly the oil used that determines the ratio. The 50-1 mix became the
standard shortly after the so-called "50-1 oil" came out and became
readily available, I think in the 50's.

A few folks with gryos and ultralights tried the very expensive "100-1
oil" and shortly faced engine rebuilds.

BTW, the gyro engine was high compression. I've been racking my brain
trying to remember, but am coming up blank. Anyway, that's why the 130
Octane gas.

Rick