What do you do given some two-stroke tools are 40:1 while others are 50:1?
a) Do you maintain two separate gas cans?
b) Do you make it 45:1 for all of them?
c) Do you use 40:1 or 50:1 for all of them?
Note: Tools are chainsaw, hedge trimmer, weed whacker, air blower, etc.
How critical is the exact oil:gasoline ratio anyway?
if you use a good quality oil like the stihl oil, you can run everything
at 50:1. We even run the old lawnboys which were supposedly designed
for 16:1 on 50:1 with out problems.
--
Steve Barker
remove the "not" from my address to email
I would probably use 50:1 in all of them, and make sure it was really
really good oil. Echo or Stihl brand chainsaw oil, or maybe Quicksilver
synthetic PWC oil.
For 2-cycle tools that I don't use very often, I've starting mixing fuel
in a 500ml pop bottle and measure the oil with a syringe. One tank of
fuel for most small engines. If you do the same you could custom mix it
for each tool.
-Bob
More oil is better for engine life but many engines run poorly at
richer oil mixes. I have a 1984 lawnboy designed for 32-1 and I run
synthetic at maybe 40 to 46 - 1. Id say use a good synthetic and see
how they run and try one mix
Hi,
For me, I'll settle for 45"1 with best oil you can get.
This thread will run a while, until someone quotes
Confucious or Aristotle. Here we go, again.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"SF Man" <lavo...@sbcglobal.net> wrote in message
news:itb690$vjl$1...@speranza.aioe.org...
Yes, I've got a straight-sided jug that I use to do the same, which I
marked off for the tank capacities of different tools. Good tip on the
syringe; for the oil I've got a little marked-off cup thing which I think
came from a tub of laundry cleaner, but the syringe would probably work
better.
I think for 50:1 v 40:1 it's "close enough" that it wouldn't matter using
the same mix, but I've got a little tiller which likes a lot of oil and
runs on 24:1.
cheers
Jules
I'd go with 40:1 and risk a fouled plug in the 50 engine. If that happens,
you can always go lighter, but once the engine is seized, changing the mix
won't help.
I am not an expert but I always considered it important enough to mark
separate cans for my chain saw and weed eater which use different
mixes. I generally use Stihl oil in both.
RonB
The secret is to use good 50:1 oil. Never use an oil that is only
designed for 40:1 at 50:1 - and PWC oil is not necessarily acceptable,
at any ratio, for air cooled power tools. You want AIR COOLED two
stroke oil. (they run hotter than water cooled engines)
>On Wed, 15 Jun 2011 20:30:50 -0400, "Stormin Mormon"
><cayoung61**spamblock##@hotmail.com> wrote:
>
>>Too much oil, and you foul spark plugs. Too little, and you
>>sieze the engine. I run 32:1 in my two cycle equipment, and
>>risk the fouling.
>>
>>This thread will run a while, until someone quotes
>>Confucious or Aristotle. Here we go, again.
>
>Hillbilly Confucius: 'Risk fouling the spark plug and not seizing
>engine.'
It's not just plug fouling - it is also carbon build-up.
In Burkina Faso (and many other African countries) they run the oil
mix extra strong on their mopeds to keep them from seizing up in the
heat - wevery month or so it's pop off the cyl head and scrape the
carbon off the head, piston, and ports with a wooden stick..
Smoke like a fiend!!!
>Smart fellers huh?!
>
>Do they change the head gasket or maybe use Permatex <G>
Generally they re-use the head gasket - quite often they make their
own replacement out of sheet copper, and anneal it every couple times
they take it off - just throw it on the fire, pull it out and quench
it.
Many of the Mopeds running around in Ougedougou and other cities are
OLD colonial era units - Solex, Peugeot, Motobecane, Mobylette? etc
from the early to mid sixties. Then there are the later Hondas etc and
the new Tomy and other Chinese units. Many of the old ones have very
little paint left on them - sun-bleached and worn to a fine patina.
Thanks for that idea Bob. I had not thought of that.
Since the fuel tanks are so very small, that's an option (I'd have to
measure each one though and get a syringe, as you noted).
Hi Jules,
Thanks for that tip, on top of Bob's suggestion.
I see if I get the right sized jug, I can mark it for the capacity of each
tool, and, ad hoc, mix the oil and gas at the time of fill.
Of course, that's a problem with partial fills.
So, I would have to do a behavioral modification (full fills only allowed).
That's also a maintenance requirement (every 30 hours of run-time, IIRC)
for the B&S engine in my mower. The head gaskets seem designed to be
reusable, at least to a certain extent. I expect it might be a
requirement for a lot of yard equipment, but nobody ever bothers :-)
cheers
Jules
Yes, that's the main drawback. OTOH, I never know how much I'm going to
be using each tool each season, and I don't want leftover mixes sitting
around, so I just got into the habit of running them dry before re-
filling.
I suppose the jug could be marked for fractions of a tank, too, but
that's perhaps more trouble than it's worth :-)
cheers
Jules
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"SF Man" <lavo...@sbcglobal.net> wrote in message
news:itc8ot$j8j$1...@speranza.aioe.org...
I've pulled the head oftermore like 60 hours and not enough carbon to
worry about on both Tecumseh and Briggs engines with unleaded gas.
Bach when gas was leaded it was a different situation -
lead/ash/carbon deposits were sizeable and HARD.
> not enough carbon to worry about ... with unleaded gas.
Interestingly, the local tool shed strongly advises 89 or 91 AKI (octane
rating) of not more than 10% ethanol (which, here in California, is almost
impossible not to use).
I'm not sure why they are so strong about not using 87 AKI with the
two-stroke motors.
When I asked them about the 40:1 and 50:1 ratios, they tried to sell me
this 'stuff' in a can which they say lasts forever and has the oil and gas
already mixed (so they were of no real use).
I trust you guys - 'cuz you're not making money off of me - and I can trust
your advice.
>On Thu, 16 Jun 2011 21:14:14 -0400, cl...@snyder.on.ca wrote:
>
>> not enough carbon to worry about ... with unleaded gas.
>
>Interestingly, the local tool shed strongly advises 89 or 91 AKI (octane
>rating) of not more than 10% ethanol (which, here in California, is almost
>impossible not to use).
>
>I'm not sure why they are so strong about not using 87 AKI with the
>two-stroke motors.
Small high output 2 strokes are high compression motors - and oil
mixed with the fuel drops the AKI significantly - starting with 98
MIGHT yeild 87, 91 might give you 89
> oil mixed with the fuel drops the AKI significantly - starting with 98
> MIGHT yeild 87, 91 might give you 89
I'm not doubting you ('cuz I don't know) ... and I had never thought about
what oil does to the octane rating ... but ...
I would 'think' that oil would be harder to burn than gasoline ... so ...
adding oil ... I would think ... would RAISE the octane rating.
Are you sure oil lowers the octane rating?
> I generally use Stihl oil in both.
In doing research on the oil & ratio, I find the following tidbits of
interest:
- Two-stroke oil reduces the octane rating by about 2 points.
- Two-stroke oil raises the octane rating (by an unspecified amount).
- All Echo 2-stroke equipment requires 89 octane gasoline with ISO-L-EGD &
JASO M345 FC/FD two-stroke oil
- Using more two-stroke oil (i.e., 40:1 vs 50:1) will not help your engine.
- Do not use synthetic two-stroke oil.
- Two-stroke oil reduces the octane rating by about 2 points.
"First, when fuel is premixed with 2-stroke oil, the octane rating is
reduced by about 2 points. An 87 octane fuel would therefore become 85
octane. Second, fuel evaporates and loses its octane rating when it lays in
your aircraft's fuel tank or in a plastic jug. A "premium", 91 octane fuel
will see its octane rating reduced to unusable levels after as little as
three weeks. Fuel with a lower octane rating would obviously have an even
shorter usable life.
REFERENCE: http://www.rotaxservice.com/rotax_tips/rotax_feed2.htm
- Two-stroke oil raises the octane rating (by an unspecified amount).
"adding oil to the gasoline will raise the octane. The amount that it will
raise the octane though would be very little. The reason for this is
twofold. First, with a fuel-oil ratio on the order of 25:1 - 50:1, there is
actually very little oil added to the gasoline. Second, when the oil/gas
mixture enters the cylinder, the oil will "drop out" while the gasoline
will remain a vapor. this is due the oil's lower vaporization rate. If the
oil didn't do this, there would be no lubricating effect and the engine
would quickly seize."
REFERENCE:
http://www.wmi.org/bassfish/bassboard/boats_motors/message.html?message_id=184343
- Using more two-stroke oil (i.e., 40:1 vs 50:1) will not help your engine.
"The ratio is 50 to 1, or 2%. This means you would mix 400mL of oil in 20L
of fuel, 500mL for 25L, and so on. Using more oil than recommended would
not help your engine in any way: it will accelerate the formation of carbon
deposits which will eventually break loose and accelerate wear."
REFERENCE: http://www.rotaxservice.com/rotax_tips/rotax_feed2.htm
- All Echo 2-stroke equipment requires 89 octane gasoline with ISO-L-EGD &
JASO M345 FC/FD two-stroke oil
"ISO-L-EGD and JASO M345 FC/FD oil must be used with a mid-grade (89
octane) or premium gasoline in all 1997 and newer engines."
REFERENCE:
http://hubersgarage.com/yahoo_site_admin/assets/docs/ECHO_FUEL.10073242.doc
- Do not use synthetic two-stroke oil.
"Synthetic oil should only be used by those who operate their engine nearly
every day. Even when shut down, air is constantly circulating through a
2-stroke engine; it is never sealed like a 4-stroke engine. Even though it
has excellent lubricating properties, a synthetic oil does not effectively
protect a stopped 2-stroke engine against corrosion: it tends to attract
moisture and will run off the parts rather than leave a protective
coating."
REFERENCE: http://www.rotaxservice.com/rotax_tips/rotax_feed2.htm
The ratio depends more on the oil than it does the equipment. I run
everything I have on marine 2 stroke oil at 50:1. We have a jetski so
we buy oil by the gallon. I've been doing it fo years and haven't had
a problem. My chainsaw is 30 years old. I've got a lawnboy that is
20 years old.
Your thinking is correct. the reason they recommend the higher octane
is solely the compression ratios.
--
Steve Barker
remove the "not" from my address to email
I also ran about 50 gallons a week of 50:1 mix gas through about 30
pieces of equipment, for almost 2 years. (That's a lot of gas and oil)
Using only quicksilver oil mix. THEN the stihl guy caught wind of it
and advised us that any lubrication based warranty claims we might have
could be denied, so i switched to the stihl oil.
Th stihl guy is lying to you. There are consumer protection laws that
prevent any manufacturer from voiding a warranty claim as long as you
have used oil that meets or exceeds the equipment requirement. No
matter who made the oil. You can use the walmart oil and they can't
do a thing about it.
That's true, but the merc quicksilver oil is certified for water cooled.
I doubt it meets the requirements for the air cooled spec.
>On Thu, 16 Jun 2011 22:28:52 -0400, cl...@snyder.on.ca wrote:
Absolutely sure - and I'm likely one in a thousand on this group that
actually understands octane and detonation in an internal combustion
engine.
Octane of a fuel has NOTHING to do with how fast it burns - and if it
did, FASTER burning fuel would have a higher AKI or octane rating.
This is because of the way detonation happens - unburned fuel -
endgasses - in the cyl dissassociate into hydrogen and oxygen
radicals, which are extremey active and explosive. This only happens
with temerature and pressure over time - so if the fuel burns FAST
there is less endgas in the cyl, for a shorter time - so less chance
of disassociation and detonation. (also part of the reason an engine
knocks more at low speed than at high speed, generally speaking.
This is a very "dumbed down" explanation - but it is accurate as far
as it goes.
>On Wed, 15 Jun 2011 18:51:57 -0700 (PDT), RonB wrote:
4 out of 5 of those references are accurate. The one that is not is
the one from Bubba the BassFisher.
As far as the one about not using more than recommended, it is only
accurate if using the correct oil. If NOT using the correct oil, more
oil may provide close to the same protection as using the right amount
of the right oil. - but it IS true.
As for not using synthetic 2 stroke oil, it is also accurate -
particularly with a simple port timed 2 stroke. A rotary valve or Rave
valve 2 stroke is more of a sealed system when shut down, suffering
less from moisture and corrosion issues - the ideal may be to use a
semi synthetic - just enough "real" oil to provide some anti-corrosion
protection, while most of the lubrication is provided by the
"smokeless" synthetic.
On a $99 weedeater I wouldnt worry too much about it, but on an $8000
Rotax aircraft engine Iwould pay heed to their warnings.
The problem with Bubba the Bassfisher's assertion that oil increases
the octane rating is that it is just plane WRONG (hey, don't take my
word for it - Echo, and Rotax - MAJOR manufacturers of 2 stroke
engines agree)
But using oil for a water cooled 2 stroke in a highly stressed air
cooled engine is NOT recommended (generally) and MAY require a
different mixture. Some, but not all "outboard motor oil" is suitable
and meets the JASO M345 FD spec.
If it only meets tc/w3 it is not recommended for, for instance, chain
saw use. JASO M345 Fd severely limits engine deposits and reduces
smoke, as well as requiring minimum lubricity levels etc.
No, it is not correct. Oil reduces the AKI of a fuel.
And if you read to the bottom of the bassfisher blog you would see
that the error was corrected.
True - as long as it meets or excedes the published spec.
If it does not, and they can prove it - you have no warranty.
The Bruce Hamilton gasoline FAQ covers octane ratings in detail:
http://www.faqs.org/faqs/autos/gasoline-faq/
Unfortunately, Bruce didn't add a question to the FAQ of:
- Does adding 2-stroke oil to gasoline raise or lower the octane rating?
So, I will send him an email asking him to include that in the next
revision of the Gasoline FAQ so that we may all benefit.
If he provides an answer via email, I'll post it here.
>>Are you sure oil lowers the octane rating?
> Absolutely sure - and I'm likely one in a thousand on this group that
> actually understands octane
Still googling, I find this which backs you up:
http://www.off-road.com/dirtbike/tech/two-stroke-gasoil-ratios-20502.html
"When all of the two strokes (the old days) were developed, they all used
Castrol petroleum oil at a 20:1 ratio and found that 92 octane gas had the
octane reduced to 72 with presence of that much oil. Modern oils won’t
affect the fuel quite as much, but if you started with 86 or 87 octane
regular fuel, you can see where you’ll end with a very low octane mix. You
could end up with a “pinging” bike."
Look at the Quicksilver PWC oil. It is certified for air-cooled and not
water cooled. It's expensive; I think it's about $9 a quart at Walmart.
I haven't bought it because I'm still working on a bottle of Castrol
2-cycle oil.
-Bob