So do when discussing or choosing an oil ratio, do we just presume that all oils are the same therefore you get the same protection/performance at 40:1 regardless of oil type? Is 40:1 the same amount of oil if a group 5 oil is used compared too an oil that's group 1?
What fuel mix ratio best for M-tronic saws?
- Thread starter jeffbecky1
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drf255
BAD CAD
Great oil, but very viscous.
I run Motul800 which is quite similar in viscosity. At 32:1 on a cold day in a ported saw that required more fuel flow than the average bear, the M-Tronic didn’t like it. Switched to 40:1 and all the problems went away.
50:1 is EPA stuff. I’d go 40:1 minimum.
In most '0' series saws, eg 070/090,034, 044 ,056, 076 etc, the Stihl owners manual reads.....'Or 25:1 (25 parts gasoline to 1 part oil ) with other branded two stroke air cooled engine oils.'
i agree, VW dieselgate springs to mind, if stihl had to run @50:1 in order to scrape through the emission test then they legally have to recommend that mix
Fatherwheels
Addicted to ArboristSite
Father used to open a litre bottle of two stroke for water cooled boat engines, tip in
as much as he thought was enough, old Stihl 041 still runs 40 years later.
Not suggesting anyone try this, just saying all that oil did nothing bad to the saw,
its not carboned up either, nor was it babied.
Stihl recommended 40:1 mix , speaks volumes to me.
Am sure newer oils offer better lubricious and burn cleaner,
but does the engine get proper lubrication at 50:1 , or are the
manufacturers just getting through the EPA test using less oil
to keep the figures at acceptable levels, they are never going to
tell us that.
Stihl 041 AV Specifications Information
SERIES OR ASSEMBLY NUMBER: 1110
ENGINE DISPLACEMENT: 61ccm 93.72 cu. in.)
CYLINDER BORE: 44mm (1.73 in.)
PISTON STROKE: 40mm (1.57 in.)
CYLINDER TYPE: Aluminum with chrome plated bore
INTAKE METHOD: Piston ported
MANUFACTURER ADVERTISED H.P.: 5.5
WEIGHT: 16 lbs. with 13 in. bar & chain
CLUTCH: Centrifugal
DRIVE TYPE: Direct
CONSTRUCTION: Die cast magnesium
MAGNETO TYPE: Bosch
CARBURETOR:Tillotson HS-29A, B, C, D, HS-77A, B, C, HS-87A, HS-100A, HS-138A, HS-208A
MAJOR REPAIR KIT: RK-21HS for HS-87, HS100RK-23HS for HS-29, HS-77, HS-138, HS208
MINOR REPAIR KIT: DG-3HS/T for HS-87, HS100 DG-5HS/T for HS-29, HS-77, HS-138, HS-208
AIR FILTER SYSTEM: Nylon mesh element
STARTER TYPE:Stihl automatic rewind
OIL PUMP: Automatic
IGNITION TIMING: 0.095 to 0.102 in. before TDC
BREAKER POINT SETTING: 0.35 to 0.40mm (0.014 to 0.016 in.)
SPARK PLUG TYPE: Bosch WSR56F
SPARK PLUG GAP: 0.51mm (0.020 in.)
CRANKSHAFT MAIN BEARINGS: Ball
FUEL OIL RATIO: 40:1 with Stihl oil
RECOMMENDED FUEL OCTANE: Regular
MIX OIL SPECIFICATION: Stihl two-cycle chain saw mix oil
SHORTEST GUIDE BAR SUPPLIED: 33cm (13 in.)
LONGEST GUIDE BAR SUPPLIED: 63cm (25 in.)
as much as he thought was enough, old Stihl 041 still runs 40 years later.
Not suggesting anyone try this, just saying all that oil did nothing bad to the saw,
its not carboned up either, nor was it babied.
Stihl recommended 40:1 mix , speaks volumes to me.
Am sure newer oils offer better lubricious and burn cleaner,
but does the engine get proper lubrication at 50:1 , or are the
manufacturers just getting through the EPA test using less oil
to keep the figures at acceptable levels, they are never going to
tell us that.
Stihl 041 AV Specifications Information
SERIES OR ASSEMBLY NUMBER: 1110
ENGINE DISPLACEMENT: 61ccm 93.72 cu. in.)
CYLINDER BORE: 44mm (1.73 in.)
PISTON STROKE: 40mm (1.57 in.)
CYLINDER TYPE: Aluminum with chrome plated bore
INTAKE METHOD: Piston ported
MANUFACTURER ADVERTISED H.P.: 5.5
WEIGHT: 16 lbs. with 13 in. bar & chain
CLUTCH: Centrifugal
DRIVE TYPE: Direct
CONSTRUCTION: Die cast magnesium
MAGNETO TYPE: Bosch
CARBURETOR:Tillotson HS-29A, B, C, D, HS-77A, B, C, HS-87A, HS-100A, HS-138A, HS-208A
MAJOR REPAIR KIT: RK-21HS for HS-87, HS100RK-23HS for HS-29, HS-77, HS-138, HS208
MINOR REPAIR KIT: DG-3HS/T for HS-87, HS100 DG-5HS/T for HS-29, HS-77, HS-138, HS-208
AIR FILTER SYSTEM: Nylon mesh element
STARTER TYPE:Stihl automatic rewind
OIL PUMP: Automatic
IGNITION TIMING: 0.095 to 0.102 in. before TDC
BREAKER POINT SETTING: 0.35 to 0.40mm (0.014 to 0.016 in.)
SPARK PLUG TYPE: Bosch WSR56F
SPARK PLUG GAP: 0.51mm (0.020 in.)
CRANKSHAFT MAIN BEARINGS: Ball
FUEL OIL RATIO: 40:1 with Stihl oil
RECOMMENDED FUEL OCTANE: Regular
MIX OIL SPECIFICATION: Stihl two-cycle chain saw mix oil
SHORTEST GUIDE BAR SUPPLIED: 33cm (13 in.)
LONGEST GUIDE BAR SUPPLIED: 63cm (25 in.)
No wonder your stash ran out , you were using too much of it, you've pissed it away.
Well at least your handle, (name), fits you.....
Run ‘em at 50:1. That’s what the manual says. 50:1 isn’t EPA mandated, it’s the manufacturers knowing their product. No engineer (me included) is going to recommend anything to cause a premature failure of any component. I know, some things are engineered to fail to either being in revenue from repair or replacement, and so on. 50:1 isn’t one of those.
That said, if 40:1 makes you feel better, go for it. It’s not that big a deal. You’re going from 2% to 2.5%. Run whatever you want with good fuel and a good oil. If you go through a lot of fuel then the ethanol stuff doesn’t matter anyway.
My 441, and the crew saws, have run somewhere between 40:1 and 50:1 of either HP Ultra or Amsoil Saber when I got a bunch cheap. They’ve all worked well and had a good, long service life on whatever the “premium” pump gas was or the gas in the shop tank. (91 e-free) The saw will compensate for your mix.
That said, if 40:1 makes you feel better, go for it. It’s not that big a deal. You’re going from 2% to 2.5%. Run whatever you want with good fuel and a good oil. If you go through a lot of fuel then the ethanol stuff doesn’t matter anyway.
My 441, and the crew saws, have run somewhere between 40:1 and 50:1 of either HP Ultra or Amsoil Saber when I got a bunch cheap. They’ve all worked well and had a good, long service life on whatever the “premium” pump gas was or the gas in the shop tank. (91 e-free) The saw will compensate for your mix.
You bet, I wish I had all that money people piss away on old superstitions, I'd be a very wealthy man.
Haironyourchest
Addicted to ArboristSite
40:1 HP Ultra in my equipment. 2 M-tronics and various other machines and makes, old and new. One crank bearing failure in my 461 but that was due to running half throttle, operator error.
Can anyone post a link to the supposed EPA 50:1 mandate? I'd like to know if it's really an urban myth or not.
Can anyone post a link to the supposed EPA 50:1 mandate? I'd like to know if it's really an urban myth or not.
i doubt if the manufacturers would publish their emission figures ? it must be pretty borderline tho
even fuel injected 2 stroke scooters are expected to fail next years euro5 emissions
Gypo Logger
Timber Baron
I think this theory that if some is good, than more is better is not right.
50:1 is an idiot proof ratio on most saws out there because the majority of saws are running too fat on either H or L or both causing a carbon buildup. Take that same fat running 50:1 saw and lean it out to factory specs and your looking at a piston score on the exhaust side.
A fatter mix is good only for those who know how to run, build and adjust their saws for best performance.
I put 500 ml of mix in 16 litres of gas.
50:1 is an idiot proof ratio on most saws out there because the majority of saws are running too fat on either H or L or both causing a carbon buildup. Take that same fat running 50:1 saw and lean it out to factory specs and your looking at a piston score on the exhaust side.
A fatter mix is good only for those who know how to run, build and adjust their saws for best performance.
I put 500 ml of mix in 16 litres of gas.
nettle
ArboristSite Member
I may be wrong but I think the Stihl 50:1 recommendation has been around longer than the EPA.
