I've always used regular fuel to mix 32:1. Recently purchased a Stihl chainsaw with with 4 stroke engine that uses 50:1 fuel mix. Owner's manual specifies mid octane fuel. Why? Seems to me the oil is already going to raise the octane (make the fule less easy to ignite). In the past, using higher octane fuel with fuel mix was a sure way to foul spark plugs. My first few gallons in this machine and my other regular 2-cycles was with regular octane and Stihl Ultra, but my last mix was with mid grade and so far not a danged bit of difference. I do cheat and mix 32:1 so the same fuel is suitable in all of my chan saws and brush cutters - seems fine in all including the new 4 stroke oil burner.
Fuel grade with 2 cycle oil
- Thread starter prs
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Oil lowers octane.
32 to 1 and you will carbon up that stihl and kill it. I work at a dealership and help service them once a week we are cleaning exhaust screens and mufflers. Run midgrade and it will help with life span.
hate2work sells Stihl equipment and recommends Stihl Ultra synthetic 2 cycle oil mixed at a 50:1 ratio for the 4 cycle engines.
I own several pieces of Stihl equipment myself and have never encountered any difficulties by following the recommendations in the owners manual (mid grade or premium gas and Stihl oil mixed at 50:1). I have an FS-36 string trimmer, which is an entry level string trimmer that has been working for me for 11 years using Stihl orange bottle oil mixed with mid grade Exxon or Shell gas at a 50:1 ratio.
Only this past year did I have to clean the exhaust screen on the string trimmer. Other than that, my only maintenance was to drain gas at the end of the year and replace spark plugs every 100 hours of use.
Stihl is good equipment. Follow the owners manual recommendations and it will last you a good long time.
I own several pieces of Stihl equipment myself and have never encountered any difficulties by following the recommendations in the owners manual (mid grade or premium gas and Stihl oil mixed at 50:1). I have an FS-36 string trimmer, which is an entry level string trimmer that has been working for me for 11 years using Stihl orange bottle oil mixed with mid grade Exxon or Shell gas at a 50:1 ratio.
Only this past year did I have to clean the exhaust screen on the string trimmer. Other than that, my only maintenance was to drain gas at the end of the year and replace spark plugs every 100 hours of use.
Stihl is good equipment. Follow the owners manual recommendations and it will last you a good long time.
I always used regular gas in a 20 year old weedeater trimmer. I never liked how it ran. Hard to start and keep running. I bought an echo chain saw years ago and it required midoctane gas. I started running mid octane in the weedeater and it was like a new machine. Ran much better and easier to start. I always run mid octane gas or higher now and my 2-strokes start easy and run well.
My collection consists of the 20 year old weedeater, echo chain saw, echo trimmer and echo edger now.
My collection consists of the 20 year old weedeater, echo chain saw, echo trimmer and echo edger now.
OK, I'll change my evil ways. Now, some of my equipment goes back to the early 1970's; a couple of Super XLAO Homelite saws and a Red Max brush cutter than is not much younger. The Homelites were originally supposed to use 16:1, but do great on 32:1 -- so now maybe with better oils they can tolerate the 50:1 too? Its all gonna be one mix, one way or the other.
prs
prs
Originally Posted By: prs
I've always used regular fuel to mix 32:1. Recently purchased a Stihl chainsaw with with 4 stroke engine that uses 50:1 fuel mix. Owner's manual specifies mid octane fuel. Why? Seems to me the oil is already going to raise the octane (make the fule less easy to ignite). In the past, using higher octane fuel with fuel mix was a sure way to foul spark plugs. My first few gallons in this machine and my other regular 2-cycles was with regular octane and Stihl Ultra, but my last mix was with mid grade and so far not a danged bit of difference. I do cheat and mix 32:1 so the same fuel is suitable in all of my chan saws and brush cutters - seems fine in all including the new 4 stroke oil burner.
Stihl came out with a 4 cycle chainsaw? What model?
Anyway, Stihl recommends 89 octane minimum in the owners manual. Also any equipment calling for either 32:1 or 40:1 can safely be run at 50:1 with modern day 2 cycle oil.
I've always used regular fuel to mix 32:1. Recently purchased a Stihl chainsaw with with 4 stroke engine that uses 50:1 fuel mix. Owner's manual specifies mid octane fuel. Why? Seems to me the oil is already going to raise the octane (make the fule less easy to ignite). In the past, using higher octane fuel with fuel mix was a sure way to foul spark plugs. My first few gallons in this machine and my other regular 2-cycles was with regular octane and Stihl Ultra, but my last mix was with mid grade and so far not a danged bit of difference. I do cheat and mix 32:1 so the same fuel is suitable in all of my chan saws and brush cutters - seems fine in all including the new 4 stroke oil burner.
Stihl came out with a 4 cycle chainsaw? What model?
Anyway, Stihl recommends 89 octane minimum in the owners manual. Also any equipment calling for either 32:1 or 40:1 can safely be run at 50:1 with modern day 2 cycle oil.
i second that you should not use 32/1 in a sthil 4 mix. if you instist on one mix only for all use amzoil sabre at 50/1 in all
Bear, go to the Stihl site and you will see their new 4-stroke fuel lubricated line of engines on different equipment. Min is a commercial grade pole pounted chainsaw. Little sucker runs great. I've mixed my last batch of fuel at 50:1 with mid grade non-ethel fuel and the Stihl synthetic lube. The Stihl pole saw, the Red Max brush cutter, and the Husky brush cutter all seem to do very well on it without getting over heated. Have not tried teh old Homelite saws yet, but there is huge dead black oak just on the cusp of falling into my pasture so its gonna happen.
prs
prs
My 45-year old Lawn Boy mower and my 44-year old Lawn Boy edger run on premium unleaded fuel without any ethanol at a 32:1 mix. Both run as good as they did when purchased new.
Yes around here non ethanol gas is 87 octane, the midgrade ethanol blend is 89, and premium is 91 or 92. Some has ethanol and some does not as far as premium goes. I run Shell 87 regular octane in my 2 stoke equipment with synthetic oil and never have had one issue.
I run regular pump gas in all of my equipment, two and four stroke. Never had an fuel related issue other than contamination from dirt and/or water. I've tried different grades of fuel and really saw no discernible difference.
Personally, I think when people pay more for fuel or oil, they expect an improvement. More often than not, there isn't any real change in the operation of the engine but the owner "seems" to detect/observe an improvement. Kind of like the placebo effect.
Personally, I think when people pay more for fuel or oil, they expect an improvement. More often than not, there isn't any real change in the operation of the engine but the owner "seems" to detect/observe an improvement. Kind of like the placebo effect.
I always use 89 octane in my power equipment. I also always add Stabil.
Something to consider with actual 2 stroke engines. Low octane fuels are more prone to detonation. Deto results in more rapid heating of the piston. That causes expansion and the classic 2 stroke piston seizure. That is why one should always use the highest octane commonly available in the typical 2 stroke. Regardless of power output or need.
The 4mix engine type is an unknown to me. However, I suspect that the same applies, as the underside of the piston is not cooled by a large quantity of engine oil as it would be in a conventional 4 stroke.
The 4mix engine type is an unknown to me. However, I suspect that the same applies, as the underside of the piston is not cooled by a large quantity of engine oil as it would be in a conventional 4 stroke.
Originally Posted By: Cujet
Something to consider with actual 2 stroke engines. Low octane fuels are more prone to detonation. Deto results in more rapid heating of the piston. That causes expansion and the classic 2 stroke piston seizure. That is why one should always use the highest octane commonly available in the typical 2 stroke. Regardless of power output or need.
The 4mix engine type is an unknown to me. However, I suspect that the same applies, as the underside of the piston is not cooled by a large quantity of engine oil as it would be in a conventional 4 stroke.
In theory you may be correct but in reality, regular gas will NOT cause detonation in a two cycle engine simply due to the fuel.
Timing and carbon build up and are the prime cause of detonation. I presently own at least 17 machines with two cycle engines and some of these machines are 38 years old and all are running great. All have been run on nothing but regular pump gas and none have ever caused me a problem of any sort due to fuel. Regular octane pump gas will work fine in all two cycle engines that are properly set up and not modified to increase compression.
Run the regular pump gas and don't sweat it.
Something to consider with actual 2 stroke engines. Low octane fuels are more prone to detonation. Deto results in more rapid heating of the piston. That causes expansion and the classic 2 stroke piston seizure. That is why one should always use the highest octane commonly available in the typical 2 stroke. Regardless of power output or need.
The 4mix engine type is an unknown to me. However, I suspect that the same applies, as the underside of the piston is not cooled by a large quantity of engine oil as it would be in a conventional 4 stroke.
In theory you may be correct but in reality, regular gas will NOT cause detonation in a two cycle engine simply due to the fuel.
Timing and carbon build up and are the prime cause of detonation. I presently own at least 17 machines with two cycle engines and some of these machines are 38 years old and all are running great. All have been run on nothing but regular pump gas and none have ever caused me a problem of any sort due to fuel. Regular octane pump gas will work fine in all two cycle engines that are properly set up and not modified to increase compression.
Run the regular pump gas and don't sweat it.
Originally Posted By: boraticus
Regular octane pump gas will work fine in all two cycle engines that are properly set up and not modified to increase compression.
Run the regular pump gas and don't sweat it.
Regular octane pump gas will work fine in all two cycle engines that are properly set up and not modified to increase compression.
Run the regular pump gas and don't sweat it.
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