Two-Stroke Oils: All the Same?
- Thread starter Paul Bunions
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Go to the JASO FD list and find one oil that's ashless. Now go to the NMMA web site and pull up the TCW3 list and find even one oil that isnt ashless. I would also challenge you to find one oil that's on both the TCW3 and FD list. Hint...you can waste your time if you chose, but you won't find a single example.
Now go up to the article I posted a few replies back and read why.
And I don't know how great Stihls engineers are. The 4mix engine is garbage and they got Mtronic and strato Charging technology in a European court mandated technology sharing agreement. Besides that I can guarantee that Stihl doesn't have an engineer on staff that formulates oil.
It's not about winning and losing. Sites like these are for sharing technically correct information. It's fuds like you that clog them up with stupidity.
Go to the JASO FD list and find one oil that's ashless. Now go to the NMMA web site and pull up the TCW3 list and find even one oil that isnt ashless. I would challenge you to find one oil that's on both the TCW3 and FD list. Hint...you can waste your time if you chose, but you won't find a single example.
Now go up to the article I posted a few replies back and read why.
And I don't know how great Stihls engineers are. The 4mix engine is garbage and they got Mtronic and strato Charging technology in a European court mandated technology sharing agreement. Besides that I can guarantee that Stihl doesn't have an engineer on staff that formulates oil.
It's not about winning and losing. Sites like these are for sharing technically correct information. It's fuds like you that clog them up with stupidity.
Smitty Smithsonite
ArboristSite Operative
Ok, none of you guys really thought about what I said.
Oil displaces fuel. FACT. There's no disputing physics. You can't physically have fuel where there's oil. Have you ever stood in traffic? Same principle applies.
REGARDLESS OF WHERE YOU SET YOUR FUEL SCREWS, this fact remains - you will have to turn them out farther with a heavier oil mix. Burning up engines is more of a thing in fixed-jet carburetors where it isn't as easy to throw your mixture around where it needs to be. A heavy oil mix in a 70's .. or ANY dirt bike, or float bowl carbureted 2-stroke engine can seize said engine from a lean fuel / air mixture.
Oil displaces fuel. FACT. There's no disputing physics. You can't physically have fuel where there's oil. Have you ever stood in traffic? Same principle applies.
REGARDLESS OF WHERE YOU SET YOUR FUEL SCREWS, this fact remains - you will have to turn them out farther with a heavier oil mix. Burning up engines is more of a thing in fixed-jet carburetors where it isn't as easy to throw your mixture around where it needs to be. A heavy oil mix in a 70's .. or ANY dirt bike, or float bowl carbureted 2-stroke engine can seize said engine from a lean fuel / air mixture.
kellenobrien
ArboristSite Lurker
So true it’s actually a big bonus I stand behind for the pricing ….and why almost every logger ends up with it. People forget to value their time and energy. Have you noticed the 500is weight?A carb tuning screwdriver is part of my EDC when cutting - or used to be. My carb'd saw is my backup saw now, so the tuning screwdriver stays on the truck with the backup saw.
500i is NICE.
Not only did we think about it, we thought about it the last 100 times someone tried to make this point.
Modern oils burn, and contribute more BTUs to the fuel load than an equivalent volume of gasoline. More oil = richer air/fuel ratio. Old school bean oil that didn't burn and dripped out the muffler, you'd be right, more oil would mean less gasoline and a leaner air/fuel ratio.
Whatever your views on this subject, tune for whatever you're running, and it doesn't matter.
Even if oil did or didn’t make it burn hotter?, it’s still just a twist of the screws and it’s tuned perfectly. It’s amazing the number of people that don’t realize that heat and a lean tune exhibit the same symptoms. One causes the other, and vice versa
thompsoncustom
ArboristSite Operative
The problem with your statement is "Oil" displaces "Fuel". Where oil does displace gas it's still a fuel and has more BTU's than the gas does. It's not air and doesn't make it run leaner.
In some cases richer. Nonetheless the difference is small, as most of the oil falls out of suspension anyway, if it didn't the engine wouldn't have proper lubrication.
thompsoncustom
ArboristSite Operative
Good point
Ok, calculate the differance in fuel flow between 32 and 50:1. Now calculate the increase in fuel flow required to achieve the same A/F ratio when going from 50 to 20 degrees. What's your results?
You should be tuning your saw daily anyways...
As for bikes seizing...ummm no. I've never in my life heard of or seen someone seize a bike or any other motor for that matter from increasing oil ratio.
In fact I ran a few tanks of 20:1 mix through my Husky BP blower this winter with no issues and it has a fixed jet carb... in cold temps too boot.
I think it's time to pull this one out again.
Piotr Pakuła
ArboristSite Guru
Everyone wants to be right, but the fault always lies on both sides - the wife and the mother-in-law 
Keep in mind that any liquid in the combustion chamber takes away from combustion.
Absolutely, but it still burns. Even if all that does is remove some available oxygen from the rest of the combustion process, like a drippy diesel injector, the saw still has to be tuned for it. I had to tune richer going from 40:1 to 50:1, and back leaner when I went back to 40:1.
For my use, no I haven't noticed the weight. It's heavier than my 034S, and if I was running both all day, I'm sure I'd notice the difference at the end of the day. For me, just a putz homeowner firewood guy, run it long enough to fill a couple trucks, it's not any issue at all. Done faster, I enjoy it more, well worth it.
I've cut wood for other folks, just to enjoy some trigger time on the 500i. That sure as hell never happened with the 034S.
Listen I love my 241's because they are so light and agile. Try one of those.
If I wind up needing a smaller and lighter gas saw, I'll definitely look at that.
Probably get rotten tomatoes thrown at me for this, but right now for everything I need to do in that class, my 80v Kobalt battery electric has been really good.
That's backwards from what one would expect. Did atmospheric conditions change?
Carb settings set the amount of vapor in the combustion chamber and this is why when cold two strokes need alotnof choke to get them to fire. This ensures enough vapor to actually combust. Any liquid doesn't count as far as tuning goes and this includes oil. Where oil comes into play with tuning is the fact it displaces gasoline flowing through the carb.
To put it another way. If a saw had oil injection and you increased the oiling rate your jetting in theory would not change. In practice it changes slightly with some oils based on if their diluent turns to vapor and if the oils themselves inhibit combustion, which many cheap ones do.
KostasVolos
ArboristSite Operative
Has anybody heard of
"Velvet pistons" 2T mix oil?
From the label ,back side :
"Distilled in a small traditional oil platform ,northern of Scotland.
Left to be aged inside the finest
chromoly barrels for 12 years.
When combusted it starts with a spark of dry nuts ,only to explode into tones of fresh cocoa and dark tobacco.
An after taste of smoked cheese
is left in the muffler .
It combines perfectly with solid bars and double skip chains ."
There's a "Special Reserve" edition also ,aged 24 years .
Comes with a crystal GLENCAIRN
mix cup .
Burnbone oils are great ,
but Scottish ones do have finesse ...
"Velvet pistons" 2T mix oil?
From the label ,back side :
"Distilled in a small traditional oil platform ,northern of Scotland.
Left to be aged inside the finest
chromoly barrels for 12 years.
When combusted it starts with a spark of dry nuts ,only to explode into tones of fresh cocoa and dark tobacco.
An after taste of smoked cheese
is left in the muffler .
It combines perfectly with solid bars and double skip chains ."
There's a "Special Reserve" edition also ,aged 24 years .
Comes with a crystal GLENCAIRN
mix cup .
Burnbone oils are great ,
but Scottish ones do have finesse ...
Both ratios were tried within minutes of each other. I was running 40:1 Trufuel, somehow a can of 50:1 got snuck in. I dumped it in the saw, had to tune richer for the 50:1, and leaner again for the 40:1.
The oil burns. If it's not dripping out the muffler, then it's burning, and contributing to the fuel load.
Oil may not be getting to the combustion chamber as a vapor, but it is getting atomized, which will burn just fine. That's how diesel fuel injectors work, and the earliest ones even used compressed air. What kind of velocity is the oil pushed through the transfer ports at? Like driving a drop of oil through a straw with an air compressor.
