50:1 vs 40:1

[roostersgt]

It has everything to do with viscosity and mixture density. Carb jets and mixture can only be metered through jets and passages properly at a certain viscosity. Jetting is calibrated for a specific flow under specific variables. 40:1 is a negligible difference but the principle still stands. 50:1 is an industry standard and has been for years, any mixture richer then that is a waste of oil and a cause for increased carbon deposit and plug fouling. Choosing not to understand this is your choice.

There doesn't appear to be an "industry standard". The following manufacturers require 40:1

Troy Bilt
Poulan
Craftsman
McCulloch

These manufacturers require 50:1

Stihl
Husqvarna
Echo
Ryobi
Shindawa
Maruyama

There may be other, but I think my point has been made. A lot of saws, and I mean a lot of saws have been running just fine on a variety of fuel mixes for a long time. Quality of oil and tuning is key.

 

[nmurph]

It has everything to do with viscosity and mixture density. Carb jets and mixture can only be metered through jets and passages properly at a certain viscosity. Jetting is calibrated for a specific flow under specific variables. 40:1 is a negligible difference but the principle still stands. 50:1 is an industry standard and has been for years, any mixture richer then that is a waste of oil and a cause for increased carbon deposit and plug fouling. Choosing not to understand this is your choice.

I guarantee you that the jetting on a saw carb isn't close to sensitive enough to know whether or not it is metering 16:1 or 100:1 mix. All that is knows is that it is putting X amount of a liquid to Y amount of air. When you increase the oil, which is a non-combustible in this scenario, you are decreasing the amount of fuel mixed with the air; hence a leaner burn at a given needle setting.

Carbon deposits are a non-issue with synthetic oils.

 

[ndlawrence]

I guarantee you that the jetting on a saw carb isn't close to sensitive enough to know whether or not it is metering 16:1 or 100:1 mix. All that is knows is that it is putting X amount of a liquid to Y amount of air. When you increase the oil, which is a non-combustible in this scenario, you are decreasing the amount of fuel mixed with the air; hence a leaner burn at a given needle setting.

Carbon deposits are a non-issue with synthetic oils.

Nmurph knows what he's talking about.

 

[edisto]

It has everything to do with viscosity and mixture density. Carb jets and mixture can only be metered through jets and passages properly at a certain viscosity. Jetting is calibrated for a specific flow under specific variables. 40:1 is a negligible difference but the principle still stands. 50:1 is an industry standard and has been for years, any mixture richer then that is a waste of oil and a cause for increased carbon deposit and plug fouling. Choosing not to understand this is your choice.

And yet, in the studies I've seen, when they add more oil to the mix, power goes up, and there is less fouling.

Like you say...it's simple physics.

 

[mowoodchopper]

Is that why I have so much trouble with my saws burning up running 32:1?:msp_thumbdn:

:agree2: 100 % brad, I have ran 32 to 40 to 1 for yrs, and have yet to damage a saws top end or bottom end for that matter, everyone can spout off at the mouth all they want about how anything richer than 50-1 is worthless, but my saws run on what they do for a reason, experience, not what some smart ass on the net tells me to run them at.

 

[mowoodchopper]

Your google fu is weak. Nobody with half a brain runs 40:1 unless you are running drain oil as your mix oil. More oil does nothing for any stock saw made in the last 40 years except make it run hotter and leaner. Another oil thread by an expert who read something on the internet.

:msp_thumbdn: another expert who read something on the internet, my point exactly, who said stock saw anyway? expert

 

[fir]

the thread started 50:1 vs 40:1 there both fine no vs at all wouldn't make much diff. ( keep it simple stop splitting hairs and run what your manual tells you to run. Or run the right mix in your newest most expensive saw and run the same in all others, its just 40 to 50 not going to make or break ya.:bang:

 

[Sheldon Cooper]

You don't know.

Check your false facts because you are wrong.

 

[ndlawrence]

Check your false facts because you are wrong.

I see you got jokes now.

 

[Sheldon Cooper]

Really pretty simple stuff. Use whatever mix you're comfortable with and make sure you have your saw tuned for that ratio and there shouldn't be any "lean" issue.

Yes you are correct. I don't see why people in this thread don't understand such a simple principle.

 

[Sheldon Cooper]

There doesn't appear to be an "industry standard". The following manufacturers require 40:1

Troy Bilt
Poulan
Craftsman
McCulloch

These manufacturers require 50:1

Stihl
Husqvarna
Echo
Ryobi
Shindawa
Maruyama

There may be other, but I think my point has been made. A lot of saws, and I mean a lot of saws have been running just fine on a variety of fuel mixes for a long time. Quality of oil and tuning is key.

you can run as much oil as you want but any 2-cycle will run on 50:1 and I will bet the farm on that. If a quality oil is used there will be no issue. If you can find compelling evidence to dispute me then we can have a constructive conversation.

 

[Sheldon Cooper]

I guarantee you that the jetting on a saw carb isn't close to sensitive enough to know whether or not it is metering 16:1 or 100:1 mix. All that is knows is that it is putting X amount of a liquid to Y amount of air. When you increase the oil, which is a non-combustible in this scenario, you are decreasing the amount of fuel mixed with the air; hence a leaner burn at a given needle setting.

Carbon deposits are a non-issue with synthetic oils.

Carbon deposits are a by product of combustion even without oil mixed with the fuel. Synthetic oil doesn't burn 100% residue free.

 

[Sheldon Cooper]

Nmurph knows what he's talking about.

That's your opinion.

 

[Sheldon Cooper]

And yet, in the studies I've seen, when they add more oil to the mix, power goes up, and there is less fouling.

Like you say...it's simple physics.

Show me those studies I would like to examine them for myself.

 

[ndlawrence]

That's your opinion.

No, it's a fact.

 

[Sheldon Cooper]

:agree2: 100 % brad, I have ran 32 to 40 to 1 for yrs, and have yet to damage a saws top end or bottom end for that matter, everyone can spout off at the mouth all they want about how anything richer than 50-1 is worthless, but my saws run on what they do for a reason, experience, not what some smart ass on the net tells me to run them at.

Run whatever ratio you think you need, overkill with the oil definitely won't hurt the engine, it just isn't necessary. Manufactures have to idiot proof there equipment so a little more oil is a safety net for their warranty department.

 

[splitpost]

its all been said before ,broken down hashed out and even converted but at the end of the day run whatever you feel is right for you 20:1 to 50:1 it dont matter,just tune your carb to match

 

[ndlawrence]

run whatever ratio you think you need, overkill with the oil definitely won't hurt the engine, it just isn't necessary. Manufactures have to idiot proof there equipment so a little more oil is a safety net for their warranty department.

k.

 

[Sheldon Cooper]

I see you got jokes now.

I don't joke around when I know what I'm talking about. Ignorance is bliss for other people, not me.

 

[ndlawrence]

its all been said before ,broken down hashed out and even converted but at the end of the day run whatever you feel is right for you 20:1 to 50:1 it dont matter,just tune your carb to match

Exactly! This is right.