40:1 to rich?
- Thread starter MS460WOODCHUCK
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Mike Schuck
ArboristSite Lurker
picked up a great condition 930 Jonsered Super and the manuel says 40/1. Would 50/1 do it any harm?
I agree, Stihl engineers know more about this then we do. The only reason to run more oil is if you just like buying more oil.
Cstratton
ArboristSite Operative
Here is a piston and cylinder that was out of a Stihl 441 that was run on 100:1 Amsoil. I think I'll pass on the 100:1 BS.
While I would not run 100:1, I have used AMSOIL for 20 years at 40:1 and have never seen carbon like that! I run it in my sport quad, my 85 hp Banshee, my saws, you name it.
Cstratton
ArboristSite Operative
here put a couple of these on them!
lmfao
Chopper G
ArboristSite Member
Seems that in order for 100:1 to be viable, the oil would have to be exponentially better than other top synthetics in terms of lubricity. I know Amsoil is great stuff (I use it in some of my vehicles), but exponentially better is tough to imagine.
But with the increasing popularity of synthetic lubrication over the last 25 yrs, I would expect to see the gradual leaner ratio changes we've seen.
But with the increasing popularity of synthetic lubrication over the last 25 yrs, I would expect to see the gradual leaner ratio changes we've seen.
Edge & Engine
ArboristSite.com Sponsor
I had a guy running Klotz at 40:1 that seized his Shindaiwa trimmer engine right up. Tore it down, to find both the piston & cylinder were virtually undamaged, just a heavy buildup of gummy tar. I thought it may have been a problem with his fuel, but he was running all his saws (has a ton of them) out of the same can, with no problems.
Cstratton
ArboristSite Operative
Thats Klotz for ya! Its hard to beat the smell of the stuff though!
Thats because trimmers are not run wide open for the most part...
they also dont run the 14,500 rpms that saws do...
Even an FS250 is only 11,500-12,000...
I would bet that maybe he even runs it at very low RPM's for a good bit of time while using it....
Your talking about 2 different animals there....
tdi-rick
Addicted to ArboristSite
Ok, this thread seems to pop up every month or so....
More oil = more power. There's plenty of (racing) data out there to show this.
It's as simple as giving a better ring seal, even with the good racing oils (which tend to be heavier SAE 40 and 50 rather than the SAE 20 which most JASO FC/FD equivalent oils are)
Saw companies recommend 50:1 as
a) Stock saws have low BMEP's, (Brake mean effective pressure, a fancy term to describe specific outputs. ie. power output/cubic capacity)
This means they create less heat than other high performance two strokes so they can survive quite well on a leaner mix diet..
b) They also rev less than racing two strokes under load
I'm talking in the cut revs. These are usually somewhere from 8,500 to 10,500 RPM.
Really high performance two strokes pull much more revs at the end of a straight than a stock saw sees in the cut, anywhere up to 22,000RPM. (no, I'm not exaggerating)
Tuning revs don't really count.
c) The average saw doesn't get serviced much, let alone opened up. 50:1 may produce less carbon than 40:1 over the working life of the average saw, particularly when less than great quality oils are used.
d) Having said that, a lot of saw companies still recommend 40:1 when using non saw branded oils, (eg Dolmar) so therefore if the saw company says 40:1 is OK, I can't see an issue using 40:1 all the time.
e) The bigger saws still use richer mix's, eg. Husqvarna stipulate 25:1 in the 3120 here, and I'm pretty sure Stihl does in the 880 too.
Both of these big boys have much higher no load RPM limits than the same model saws sold in the US and are often used for milling or post ripping, so are used for long, sustained cuts.
Long cuts = lots of heat so a greater potential for skirt scuffing and seizing.
Really high output air cooled two strokes still use 16-20:1 mix ratios, even with the very best castor/syn oils like Elf HTX 976 & 909, Castrol A747 & XR77, Silkolene KR2, etc.
These type of oils are that much better than oils like Stihl Ultra under high load/high temps/high RPM's it isn't funny, yet the engines that run these oils still require 'rich' mixes to survive.
Yes, these type of engines come apart every meeting or so, so potential carbon build up isn't an issue, but they still run very cleanly (especially compared to the straight castors that I used to run 25 years ago)
Respected Stihl shops in logging areas here (Australia) recommend 40 and 32:1 to their pro customers running 660's according to MCW.
One shop owner said to Matt they definitely see less wear on the top ends of 660's with the slightly more oil in the mix saws.
Tzed250 posted some photos of one of his saw engines in a thread like this some time back using a mix IIRC of Ultra and Klotz ??
Anyway, pretty sure it was @ 32:1 and it was clean enough on the top end to eat your dinner off.
It was a combination of good oils, good fuel and a well tuned saw.
More oil = more power. There's plenty of (racing) data out there to show this.
It's as simple as giving a better ring seal, even with the good racing oils (which tend to be heavier SAE 40 and 50 rather than the SAE 20 which most JASO FC/FD equivalent oils are)
Saw companies recommend 50:1 as
a) Stock saws have low BMEP's, (Brake mean effective pressure, a fancy term to describe specific outputs. ie. power output/cubic capacity)
This means they create less heat than other high performance two strokes so they can survive quite well on a leaner mix diet..
b) They also rev less than racing two strokes under load
I'm talking in the cut revs. These are usually somewhere from 8,500 to 10,500 RPM.
Really high performance two strokes pull much more revs at the end of a straight than a stock saw sees in the cut, anywhere up to 22,000RPM. (no, I'm not exaggerating)
Tuning revs don't really count.
c) The average saw doesn't get serviced much, let alone opened up. 50:1 may produce less carbon than 40:1 over the working life of the average saw, particularly when less than great quality oils are used.
d) Having said that, a lot of saw companies still recommend 40:1 when using non saw branded oils, (eg Dolmar) so therefore if the saw company says 40:1 is OK, I can't see an issue using 40:1 all the time.
e) The bigger saws still use richer mix's, eg. Husqvarna stipulate 25:1 in the 3120 here, and I'm pretty sure Stihl does in the 880 too.
Both of these big boys have much higher no load RPM limits than the same model saws sold in the US and are often used for milling or post ripping, so are used for long, sustained cuts.
Long cuts = lots of heat so a greater potential for skirt scuffing and seizing.
Really high output air cooled two strokes still use 16-20:1 mix ratios, even with the very best castor/syn oils like Elf HTX 976 & 909, Castrol A747 & XR77, Silkolene KR2, etc.
These type of oils are that much better than oils like Stihl Ultra under high load/high temps/high RPM's it isn't funny, yet the engines that run these oils still require 'rich' mixes to survive.
Yes, these type of engines come apart every meeting or so, so potential carbon build up isn't an issue, but they still run very cleanly (especially compared to the straight castors that I used to run 25 years ago)
Respected Stihl shops in logging areas here (Australia) recommend 40 and 32:1 to their pro customers running 660's according to MCW.
One shop owner said to Matt they definitely see less wear on the top ends of 660's with the slightly more oil in the mix saws.
Tzed250 posted some photos of one of his saw engines in a thread like this some time back using a mix IIRC of Ultra and Klotz ??
Anyway, pretty sure it was @ 32:1 and it was clean enough on the top end to eat your dinner off.
It was a combination of good oils, good fuel and a well tuned saw.
tdi-rick
Addicted to ArboristSite
A saw doesn't see those sort of revs under load, it's for maybe a second before the cut starts and that's it.
High no load revs aren't good for a saw either.
Cstratton
ArboristSite Operative
VERY educated and well put response! I wish some of the dealer and service personnel that I hear about on here would read a book or 2! There are many good 2 stroke tuning books out there.
parrisw
Tree Freak
I run Amsoil Sabre at 40:1, and all I know is the insides of my saws are way cleaner then my buddie's saws, he runs Stihl regular oil at 50:1. I can't comment on Ultra, never tried it, its wayyyyyyyy too much money over here.
And trimmers are even lower than that...so thank you for proving my point....
and my point was more to the effect that most trimmers only run in the 9,000 rpm no load...so maybe thats not hot enough to burn off the extra oil...
Last edited:
To lubricate the engine, use a synthetic oil for two-stroke aircooled
engines (quality grade: JASO FC or ISO-L-EGD), which
has to be added to the fuel. The engine has been designed for
use of DOLMAR High Performance two-stroke engine oil and a
mixture ratio of ONLY 50:1 to protect the environment. In addition,
a long service life and reliable operation with a minimum emission
of exhaust gases are ensured. DOLMAR High Performance
two-stroke engine oil is available in the following sizes:
2.6 oz order number 986 100 100
6.4 oz order number 986 100 101
In case DOLMAR High Performance two-stroke engine oil is not
available, it is recommended to use a mixture ratio of 50:1 with
other synthetic two-stroke engine oils, as otherwise optimum
operation of the engine cannot be guaranteed.
The correct mixture ratio:
50:1 when using DOLMAR High Performance two-stroke
engine oil, i. e. mix 50 parts gasoline with 1 part oil.
50:1 when using other synthetic two-stroke engine oils (quality
grade JASO FC or ISO-L-EGD), i. e. mix 50 parts
gasoline with 1 part oil.
NOTE:
For preparing the fuel-oil mixture first mix the entire oil quantity with
half of the fuel required, then add the remaining fuel. Thoroughly
shake the mixture before filling it into the chain saw tank.
It is not wise to add more engine oil than specified to ensure
safe operation. This will only result in a higher production of
combus-tion residues which will pollute the environment
and clog the exhaust channel in the cylinder as well as
the muffler. In addition, fuel consumption will rise and
performance will decrease.
engines (quality grade: JASO FC or ISO-L-EGD), which
has to be added to the fuel. The engine has been designed for
use of DOLMAR High Performance two-stroke engine oil and a
mixture ratio of ONLY 50:1 to protect the environment. In addition,
a long service life and reliable operation with a minimum emission
of exhaust gases are ensured. DOLMAR High Performance
two-stroke engine oil is available in the following sizes:
2.6 oz order number 986 100 100
6.4 oz order number 986 100 101
In case DOLMAR High Performance two-stroke engine oil is not
available, it is recommended to use a mixture ratio of 50:1 with
other synthetic two-stroke engine oils, as otherwise optimum
operation of the engine cannot be guaranteed.
The correct mixture ratio:
50:1 when using DOLMAR High Performance two-stroke
engine oil, i. e. mix 50 parts gasoline with 1 part oil.
50:1 when using other synthetic two-stroke engine oils (quality
grade JASO FC or ISO-L-EGD), i. e. mix 50 parts
gasoline with 1 part oil.
NOTE:
For preparing the fuel-oil mixture first mix the entire oil quantity with
half of the fuel required, then add the remaining fuel. Thoroughly
shake the mixture before filling it into the chain saw tank.
It is not wise to add more engine oil than specified to ensure
safe operation. This will only result in a higher production of
combus-tion residues which will pollute the environment
and clog the exhaust channel in the cylinder as well as
the muffler. In addition, fuel consumption will rise and
performance will decrease.
Most of what you're seeing isn't carbon, it's discoloration from heat, the piston crown also had some erosion from heat.
85H.P. Banshee???? Frig, I bet you got some long arms from holding onto that beast, stretched eyelids and bugs stuck in yer teeth from grinning!!!:msp_w00t::msp_w00t::msp_w00t:
Tzed250
Addicted to ArboristSite
Did I hear my name mentioned?
Who needs a search when Rick has the memory of an Elephant. For those that didnt see it...
I'm curious as to whether or not this is normal carbon formation on a piston crown. This is the P&C from my new MS440. It has only seen maybe a dozen tanks of fuel. The saw has not been run excessively rich, or lean for that matter. What's odd is the the combustion chamber and exhaust port are both clean. The carbon on the piston crown was extremely hard and very difficult to remove.
Most of you know that I run Klotz R50 at 32:1. My questions are this. Is this normal? If not, is this the result of running R50? Is it the result of running 32:1? What do the masses think. And please don't just blurt out, oh you're running it too rich. Give me a reason why you think what you do.
.
This is what I call clean.
MS660 cylinder, 6-7 tanks of Amoco Ultimate premium unleaded(10% ethanol) mixed with Stihl Ultra @ 50:1, with one ounce per gallon Klotz Super Techniplate added.
This photo was taken after the saw was used to buck 40" White Oak, so the top end was under plenty of load. No pic of the piston, but what was on the crown wiped off with a paper towel.
Notice how clean the plug is.
My $.02
...
Cstratton
ArboristSite Operative
Its a BALL at the dunes! Believe it or not, it is still actually trail ridable as it is a midrange port.
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