Stihl HP Ultra - anyone have issues with this Oil

[oilstinks]

I've run Stihl ultra silver bottle semi commercially for many years now. The only engine I've lost on it it was the one that got stolen. I did however score a piston in my ms460 on Pennzoil mix years ago but it may have been an ethanol problem looking back. My Stihl oil is usually mixed 45:1 and they are run hard so I never have screen clogging issues. I think the running hard is the key to the issues all over the net about screen clogging but that's just my experience. I pulled the muffler on my ms460 yesterday to peak at the piston and everything was clean and there was an oily film on the piston for what ever that is worth. Every brand of 2 stroke I have runs the Stihl ultra HP.

 

[Ashful]

I've been using the Stihl silver (and orange before that) many years, in all manner of saws, string trimmers, edgers, and hand-held blowers. Never a problem until this summer, when I seized my first 2-stroke engine. Still haven't gotten around to pulling it apart to see where the failure was, just bought a new one to keep working, at the time. Given it was one machine after many hundreds of hours on a half dozen machines, I'm not ready to blame the oil, yet.

But some posters here gave me the good advice to err on the low side of 1 gallon, when filling my little 1 gallon mix cans with the pre-measured 2.6 oz. Stihl bottles. It's not that I'm trying to cook up my own formula in my shed ( Corey!), but rather just accounting for any measurement error I may make in the fuel, as margin for error seems very small at 50:1 ratio. I have an accurate 1 gallon mark made on each of my cans, but with the way these HDPE cans collapse or balloon with each change in the weather, or even the way the gas pump nozzle still drains a small cup full of gas into your can after you release the handle, some slight margin on the lesser side of 1.00 gallons measured seems prudent.

Like someone already mentioned above, I put a little gasoline into the drained 2.6 oz. bottle, cap and shake it, to rinse the last oil out of it and into my can. When your volumes are this small, and your ratio this lean, small errors can swing it a bit one way or the other,.

 

[qwee]

I didn't know that if the oil ratio goes higher (ie from 50:1 to 32:1) you could be putting more strain on your chainsaw because it will be running hotter. I thought I was being kinder to my saw by having extra oil in the gas. But too much oil could have the opposite effect. It puts added stress on the saw.

So, there must be a sweet spot (40:1, 45:1?). Enough oil to lubricate parts but not too much to cause the saw to overheat. I started being more careful when measuring the ratio.

 

[oilstinks]

So in running say 32:1 vs 50:1 are we actually leaning out the mix by having less gas vs oil in the 32:1? Makes sense. So a simple tune should alleviate any problems one would think.

 

[brenndatomu]

So a simple tune should alleviate any problems

Exactly

 

[qwee]

Experiment:
Three new chainsaws that are the same. The manufacturer recommends an oil ratio of 40:1. So, we run one saw at a 40:1 ratio, one at a 30:1 ratio, and one at 50:1 ratio. The 3 saws are run hard for 200 hours. Which saw is the least worn?

I would say the 40:1 saw will be the least worn. But what about the other 2? Which one is more worn the 50:1 or the 30:1 saw? I would guess the 30:1 would be the most worn due to putting more stress on the saw (overheating) than the 50:1 saw. I had to reverse my thinking on this - more oil in the fuel isn't really a good thing.

 

[Ashful]

So in running say 32:1 vs 50:1 are we actually leaning out the mix by having less gas vs oil in the 32:1? Makes sense. So a simple tune should alleviate any problems one would think.

All except the added fouling of exhaust screen, etc.

I've spent my career alternating between design engineer and R&D engineer, and get real frustrated with end users who think they're going to reason out a better program of operation on their own, than the engineering team who has spent literally many tens of thousands of man-hours on optimizing the design for a given set of parameters. If the Stihl engineers determined 50:1 is the mix ratio toward which they are going to optimize their design, you'd be foolish to think anything other than this is going to somehow be better for the saw.

When I mention erring on the side of caution, with regard to the 1.00 gallons of gasoline I mix with that 2.6 oz. pre-measured bottle of 2-stroke oil, I am speaking only of accounting for error of measurement, not re-thinking or somehow bettering the prescription.

 

[Shank]

I have been running the Sthil synthetic since they came out with it. It was my understanding they doubled there saw warranty if you used it. I don't know if that's still the case now. I use it in all my air cooled machines. It burns clean and very little plug fouling.

When I bought my trimmer the warranty was doubled if you bought the synthetic at the same time.

 

[ABMax24]

Experiment:
Three new chainsaws that are the same. The manufacturer recommends an oil ratio of 40:1. So, we run one saw at a 40:1 ratio, one at a 30:1 ratio, and one at 50:1 ratio. The 3 saws are run hard for 200 hours. Which saw is the least worn?

I would say the 40:1 saw will be the least worn. But what about the other 2? Which one is more worn the 50:1 or the 30:1 saw? I would guess the 30:1 would be the most worn due to putting more stress on the saw (overheating) than the 50:1 saw. I had to reverse my thinking on this - more oil in the fuel isn't really a good thing.

30:1 will have less wear.

Higher temperatures are not necessarily a bad thing in a 2-stroke, you definitely want to keep them hot enough to keep the carbon burnt out of the cylinder and piston rings. As long as you can keep the engine cool enough to avoid detonation and melting the piston.

In the old carbureted snowmobile days you'd jet the carb on the edge of being too lean, lean air/fuel mixtures make more power, extra fuel in the process just absorbs heat decreasing power. The fastest guys were running leanest, unfortunately sometimes to the point of melting holes in the pistons. "They always run best right before they blow up"

My saw is Autotune anyway, it will just adjust if I mix a little to much oil in the fuel.

I've spent my career alternating between design engineer and R&D engineer, and get real frustrated with end users who think they're going to reason out a better program of operation on their own, than the engineering team who has spent literally many tens of thousands of man-hours on optimizing the design for a given set of parameters. If the Stihl engineers determined 50:1 is the mix ratio toward which they are going to optimize their design, you'd be foolish to think anything other than this is going to somehow be better for the saw.

But in this case the government mandated design parameters are detrimental to engine life. 50:1 is required for the saw to meet emissions, so that is the design parameter the engineers are forced to design around.

Same deal in the diesel engine world, modern emissions equipment certainly does not increase engine reliability. An engine sucking abrasive soot back into the intake through the EGR certainly isn't good, nor is the engine working against the backpressure from the DPR or SCR. CAT left the onroad diesel engine market in 2010 for exactly this reason.

 

[Ashful]

But in this case the government mandated design parameters are detrimental to engine life. 50:1 is required for the saw to meet emissions, so that is the design parameter the engineers are forced to design around.

True. But in response, the OPE manufacturers have surely adjusted their designs, materials, and tolerances toward optimizing reliability at this new mix ratio. The thing I'm ignoring here is older equipment, which may have been made when 32:1 was the norm.

 

[ericm979]

True. But in response, the OPE manufacturers have surely adjusted their designs, materials, and tolerances toward optimizing reliability at this new mix ratio. The thing I'm ignoring here is older equipment, which may have been made when 32:1 was the norm.

What's changed the most is the oil. Modern synthetic two stroke oil is a lot better than the old stuff from the 70s or 80s. Manufacturers have to spec the oil ratio for guys who run the cheapest oil possible. Or if you go back far enough, guys who would mix cheap 30w instead of two stroke oil. Many older two strokes run fine on lower amounts of quality oil. Really old engines with plain main bearings that are also the crank seal would be an exception. Those need lots of oil to maintain a seal.

Oil amounts should vary by application. My road race two stroke motorcycle got 24:1. For regular off road two strokes I ran 32:1. My observed trials motorcycles, which saw less load and not much WFO operation ran 75:1 (water cooled) or 60:1 for vintage air cooled. Saws are fan cooled and have low HP for their displacement, but see a lot of WFO (which they are designed for). And the operator is standing right in the cloud of exhaust. Breathing aerosolized oil is not the best thing for you. 50:1 seems like a good value for saws. I use high quality synthetic oil. I already had an appropriate oil from my trials days that I know works well so I use that.

 

[salecker]

I didn't know that if the oil ratio goes higher (ie from 50:1 to 32:1) you could be putting more strain on your chainsaw because it will be running hotter. I thought I was being kinder to my saw by having extra oil in the gas. But too much oil could have the opposite effect. It puts added stress on the saw.

So, there must be a sweet spot (40:1, 45:1?). Enough oil to lubricate parts but not too much to cause the saw to overheat. I started being more careful when measuring the ratio.

The saw will only overheat if you don't tune it after you switch mix's
I run 32:1 in everything and have never lost an engine,but i tune for the mix before i start using a saw to cut wood.

 

[salecker]

All except the added fouling of exhaust screen, etc.

I've spent my career alternating between design engineer and R&D engineer, and get real frustrated with end users who think they're going to reason out a better program of operation on their own, than the engineering team who has spent literally many tens of thousands of man-hours on optimizing the design for a given set of parameters. If the Stihl engineers determined 50:1 is the mix ratio toward which they are going to optimize their design, you'd be foolish to think anything other than this is going to somehow be better for the saw.

When I mention erring on the side of caution, with regard to the 1.00 gallons of gasoline I mix with that 2.6 oz. pre-measured bottle of 2-stroke oil, I am speaking only of accounting for error of measurement, not re-thinking or somehow bettering the prescription.

The EPA is responsible for the 50:1 mix

 

[Nealm66]

Does running at a richer mix void the extended warranty they offer for running the hp?

 

[Isaac Carlson]

I have seen more clogged screens and carbon coated pistons than anything else. I don't know what oils they were using. Most people around here own a saw and you always hear them running. Most of them are rich and dull, by the sound of it. They might be a mile or more away, but you can tell how it's running by how it sounds. My wife said she can hear exactly what I am doing when I cut wood on the other side of town. She can hear the truck all the way there and then the saw running and then it gets quiet while I load up and then she hears the truck when I head home. She usually has food ready when I pull in the driveway.

 

[ericm979]

The EPA is responsible for the 50:1 mix

The earliest EPA rule regulating chainsaws that I can find was effective in 1995 (and as far as I can see does not specify oil ratios). I have a Stihl 025 which was in production from 1991-2002. Its owners manual calls for 50:1. The 038 (1980, oldest Stihl manual I can find) also recommends 50:1. So they have been recommending 50:1 since well before any EPA regulation.

I have seen the claim of the EPA requiring 50:1 before but I have yet to see any documentation. If you have some I'd love to see it.

 

[ABMax24]

The earliest EPA rule regulating chainsaws that I can find was effective in 1995 (and as far as I can see does not specify oil ratios). I have a Stihl 025 which was in production from 1991-2002. Its owners manual calls for 50:1. The 038 (1980, oldest Stihl manual I can find) also recommends 50:1. So they have been recommending 50:1 since well before any EPA regulation.

I have seen the claim of the EPA requiring 50:1 before but I have yet to see any documentation. If you have some I'd love to see it.

It's not specified specifically in the regulations that you can't run lower than "X:1" oil:fuel ratio. It's setup so there are maximum hydro carbon + nitrogen oxides (HC + NOx) quantities expressed in g/kwh released from the exhaust. Basically 2-stroke oil for the most part leaves the engine un-burned, and directly contributes to the HC portion of that formula. High quantities of oil in the fuel (say 32:1) would not likely pass the emission testing, and the OEM can't then tell the consumer to operate (mix the fuel richer than 50:1) the equipment in a way that would cause emissions outside of the limits of the standard.

Diesel engines are the exact same way, the EPA doesn't say you have to run X equipment on all engines to reduce emissions, they say here are the emission standards you must meet in g/kwh, it is up to you as the manufacturer to define how you meet those emissions requirements, and here is the test that must be run to verify your product meets the standard.

The EPA is an absolute behemoth when it comes to enforcement of the emission regulations, they will literally fine companies into bankruptcy for non-compliance. From an OEM's perspective it is better to have less reliable equipment than the EPA on your back.

Here is the standard and a key table to emission limits for handheld engines.

Table 1 to § 1054.103 - Phase 3 Emission Standards for Handheld Engines (g/kW-hr)

Engine displacement class	HC + NOX	CO
Class III	50	805
Class IV	50	805
Class V	72	603

Federal Register :: Request Access

 

[Nealm66]

So, asking again, does running at a richer mix void the extended warranty offered if you run the hp? I follow the factory recommendations but I admit my saws are definitely not treasured items and if I feel the slightest weakening or any problems at all that poses a production problem, they’re done. But so far no issues out of the ordinary. I don’t even know if there’s a wear warranty for pro use. 6 months is about time to replace but that’s about 2 gallons of fuel a day 5-6 days a week and usually the mounts are tired and everything in general looks like it went through a battle. I have replaced a top end and mounts etc.a couple times through the years but learned it’s just better to get a new one. If they don’t offer the extended warranty if you admit to running it rich than I would listen to they’re recommendation

 

[ericm979]

High quantities of oil in the fuel (say 32:1) would not likely pass the emission testing,

Do we actually know that? The fuel is the vast majority of the hydrocarbons in the engine- literally 97 or 98%. Keeping that out of the exhaust port is the reason for improvements like stratified charge porting.

But if major manufactures like Stihl were recommending 50:1 15 years before any EPA regs on saws, it seems unlikely that the EPA is the cause of the 50:1 recommendation.

 

[ericm979]

So, asking again, does running at a richer mix void the extended warranty offered if you run the hp? I follow the factory recommendations but I admit my saws are definitely not treasured items and if I feel the slightest weakening or any problems at all that poses a production problem, they’re done. But so far no issues out of the ordinary. I don’t even know if there’s a wear warranty for pro use. 6 months is about time to replace but that’s about 2 gallons of fuel a day 5-6 days a week and usually the mounts are tired and everything in general looks like it went through a battle. I have replaced a top end and mounts etc.a couple times through the years but learned it’s just better to get a new one. If they don’t offer the extended warranty if you admit to running it rich than I would listen to they’re recommendation

A dealer can try to fight honoring the warranty if they want but it's hard to see how they would in this case. The mechanic may well check that there is oil in the gas and bottom end (a better proof that it wasn't straight gassed as unscrupulous people will put premix in the tank). They're not going to know what ratio you ran it at unless you tell them.

I have not looked at the terms of the extended warranty but I thought you got it merely from buying the oil with no requirement to use it.

Ok I looked it up and it says "Double limited warranty protection applies to select STIHL gasoline-powered products purchased for personal non-income producing, household purposes only." (https://www.stihlusa.com/faq/warranty/engine-oil-double-warranty/)
So it's no good if you're commercial which it sounds like you are. And the regular warranty period is 3 months if you're not a homeowner. (https://www.stihlusa.com/WebContent/CMSFileLibrary/STIHL_Warranty_Policy_Manual_2022-11.1.pdf)

 

[salecker]

The earliest EPA rule regulating chainsaws that I can find was effective in 1995 (and as far as I can see does not specify oil ratios). I have a Stihl 025 which was in production from 1991-2002. Its owners manual calls for 50:1. The 038 (1980, oldest Stihl manual I can find) also recommends 50:1. So they have been recommending 50:1 since well before any EPA regulation.

I have seen the claim of the EPA requiring 50:1 before but I have yet to see any documentation. If you have some I'd love to see it.

A lot of people use outboard oil in their chainsaws which isn't formulated for air cooled engines

 

[ABMax24]

Do we actually know that? The fuel is the vast majority of the hydrocarbons in the engine- literally 97 or 98%. Keeping that out of the exhaust port is the reason for improvements like stratified charge porting.

But if major manufactures like Stihl were recommending 50:1 15 years before any EPA regs on saws, it seems unlikely that the EPA is the cause of the 50:1 recommendation.

Yes we know that. Not all hydro-carbons are created equal, gasolines short chains are easy to vaporize and burn. 2-stroke oil has to be deliberately hard to vaporize and burn, otherwise it wouldn't be an oil.

Regulations on handheld equipment came into effect in 2000. My dad has a McCullough saw from the late 90's that required 40:1.

Stihl is different, they developed their own oil for their engines to run at 50:1, seems like a good marketing tool, less oil to buy (and you buy their oil), and less smoke for the operator. What you've kindly left out is that 038 manual (and other manuals from that vintage) also required the oil to be mixed at 25:1 if a non-Stihl oil was used. (Page 22)

https://cdnassets.stihlusa.com/1625858564-038manual.pdf

 

[Ashful]

The EPA is responsible for the 50:1 mix

This cannot possibly be correct. My Stihl 064 was manufactured 1985 - 1993, and even that ancient manual calls for 50:1 if using Stihl brand oil. It seems Stihl was designing their saws for this mix ratio way before the EPA was involved in specifying 2-stroke oil usage.

 

[Nealm66]

I’ve never worked with anyone running their saws rich intentionally as it lowers the octane. I remember a bunch of guys running octane boost back when I was cutting for Columbia helicopter. But never have I heard of anyone running richer oil mix. At least locally here in the pnw. Seems silly to me but I guess it’s a thing. Maybe if you’re running dull chains or milling or something that puts extra heat/load on the motor? I’ve done quite a bit of milling with my 880 with the hp and no issues other than I hate the air filter but my chains cut good on and I’m not overheating it. To each his own I guess but I’d be willing to bet none of these internet experts would last a day on a hillside around here running a saw at a rich blend like 40-1. There just isn’t room in a setting for someone not bringing up a strip fast enough

 

[qwee]

He isn't high on Stihl ultra. He shows the below piston area on 2 saws and the importance of film strength. He is using boat motor 2-cycle oil.