Two stroke fuel ratios

[bwalker]

A change in humidity can also effect tune

Yep.

 

[North by Northwest]

I see about zero reason to run a FB oil when much better choices are available at reasonable prices. In fact IMO its stupid.

100 % agree .

 

[North by Northwest]

Yep.

Barametric pressure & air density changes drastically effect engines state of tune . That is why daily tuning is paramount . Even more as mentioned when warranted . Few weekend warriors realize the cause & effects , let alone keeping a clean air filter or sharp chain for that matter lol.

 

[jellyroll]

Picked up some husqvarna oil guard at the dealer Each bottle is 100 ml not sure where he got it. I heard it is very good stuff though.
how much gas to 100 ml for 40:1

 

[jellyroll]

Barametric pressure & air density changes drastically effect engines state of tune . That is why daily tuning is paramount . Even more as mentioned when warranted . Few weekend warriors realize the cause & effects , let alone keeping a clean air filter or sharp chain for that matter lol.

I know of a few that replace the chain when they get dull. Seems i got a good stock of chain at all times.

 

[OM617YOTA]

Picked up some husqvarna oil guard at the dealer Each bottle is 100 ml not sure where he got it. I heard it is very good stuff though.
how much gas to 100 ml for 40:1

100ml x 40 = 4000ml. So 4 liters of gasoline, or close enough to 1 gallon to make no difference.

 

[MacAttack]

Adding more oil only leans out your air to fuel ratio if you don't alter carb tuning parameters. The effect is rather snall.
No need for any test on this.

More for curiosity sake than anything, I 100% agree the effect is small.

 

[MacAttack]

The load put on the engine and the air temperature both have more affect than changing between any of the ratios we commonly
use. With a carb set with a crisp tune, changes in temps and load on the engine may require you to tweak it throughout the day if you really want the most from the engine.

I keep everything on the rich side, rich but still cleans up under load, gives a nice cushion of safety. I'm never needing every potential drop of optimal performance.

 

[huskihl]

Tree Monkey taught me a long time ago to look for a puddle of oil in the crankcase. Just like slightly 4 stroking out of the wood is considered a safe tune, a puddle of residual oil that has trickled into the bottom of the case is a sign that you’re using enough oil. Only makes sense.

Ratio alone isn’t a good method as some oils stay attached better at 50:1 and leave more oil behind than others do at 32:1. Many popular o p e oils leave residual oil like cheap gas station oils, regardless of the Fb, c, d…rating.

 

[Lil'Skeet]

Serious question... has there ever been a highly controlled experiment in a 'lab' environment to demonstrate whether using more oil actually creates a more 'lean' running condition? Which I'd expect to show up with an oxygen sensor in the exhaust, and also measuring engine temps, and RPMs? I'm not an engineer or scientist, just a homegrown mechanic and tinkerer.
Like was mentioned already, a better ring seal from extra oil will also make more power, so it could be difficult to prove either way?
I'm one of the weird tinfoil-hat holdouts that refuses to believe more oil leans the air / fuel ratio, but I don't get into arguments about it. It just seems based on speculation and theory without real-world evidence.
But.... I'd love to actually see the results of a controlled test!

We need to gather all of these thoughts, opinions, and ideas and bombard YouTube "project farm". He is excellent at stuff like this. I'm sure none of us will agree on that though.

 

[North by Northwest]

Tree Monkey taught me a long time ago to look for a puddle of oil in the crankcase. Just like slightly 4 stroking out of the wood is considered a safe tune, a puddle of residual oil that has trickled into the bottom of the case is a sign that you’re using enough oil. Only makes sense.

Ratio alone isn’t a good method as some oils stay attached better at 50:1 and leave more oil behind than others do at 32:1. Many popular o p e oils leave residual oil like cheap gas station oils, regardless of the Fb, c, d…rating.

Damm straight Kevin !

 

[Lil'Skeet]

There is a lot wrong with that...
For starters oil has a higher heat of evaporation than gasoline. It then stands to reason that it would take more heat out of an engine to combust it as vapors burn and liquids dont?
The reason engines run slightly hotter is because they make slightly more power with more oil.
As for Daggers comment on tolerances. Yes, tighter tolerances do leave less room from oil. However the tolerances on a air cooled chainsaw are pretty sloppy. Second, running more oil is about replenishing the oil that is combusted or expelled from the motor. The higher the rpm and load the more oil you need and make no mistake saws run at very high rpms. Thirdly, running more oil is about protection from corrosion via residual oil and protection of the rotating assembly at sustained high rpm and load. You can argue this last point, but studies have been done using oil doped with radioactive dye to measure migration time and it is as I have stated.
One last comment. Prior to strato charging bearing failures in low hour saws where much more rare than they are now. Which makes sense given that there is much less oil moving through a strato engine.
At the end of the day run what you want, but these are the facts.
Also keep in mind that most dealers setup saws pig rich and most guys can't tune a saw to save their lives. Running a saw pig rich pushes much more oil through a motor than a small change in ratio. A large swing in temperature does the same. How many of you guys stressing about running a little more oil through your saw are also tuning daily? How many of the same even know how to tune a saw properly are what a proper state of tune even is?

Have you ever thrown a gallon of old motor oil in a fire? Same with a gallon of gasoline? Motor oil is much hotter.
"1 gallon of gasoline = 120,476 Btu. 1 gallon of diesel fuel = 137,381 Btu (distillate fuel with less than 15 parts per million sulfur content) 1 gallon of heating oil = 138,500 Btu (distillate fuel with 15 to 500 parts per million sulfur content)"

GradeHeating Value
(Btu/US gal)Comments

Fuel Oil No. 1132900 - 137000Small Space Heaters

Fuel Oil No. 2137000 - 141800Residential Heating

Fuel Oil No. 4143100 - 148100Industrial Burners

Fuel Oil No. 5 (Light)146800 - 150000Preheating in General Required

Fuel Oil No.5 (Heavy)149400 - 152000Heating Required

Fuel Oil No. 6151300 - 155900Bunker C

My point being, Oil burns hot..... Once lit.
PROJECT FARM! WE NEED YOU!

 

[Lil'Skeet]

A change in humidity can also effect tune

Big time! Was 96% humidity and 88 degrees here at 4:00am this morning and all the 2 cycles were rich. Very rich.

 

[OM617YOTA]

Anyone have a tailpipe O2 sensor? I'd chip in to buy one if someone wants to do some objective testing.

 

[huskihl]

Have you ever thrown a gallon of old motor oil in a fire? Same with a gallon of gasoline? Motor oil is much hotter.
"1 gallon of gasoline = 120,476 Btu. 1 gallon of diesel fuel = 137,381 Btu (distillate fuel with less than 15 parts per million sulfur content) 1 gallon of heating oil = 138,500 Btu (distillate fuel with 15 to 500 parts per million sulfur content)"

GradeHeating Value
(Btu/US gal)Comments

Fuel Oil No. 1132900 - 137000Small Space Heaters

Fuel Oil No. 2137000 - 141800Residential Heating

Fuel Oil No. 4143100 - 148100Industrial Burners

Fuel Oil No. 5 (Light)146800 - 150000Preheating in General Required

Fuel Oil No.5 (Heavy)149400 - 152000Heating Required

Fuel Oil No. 6151300 - 155900Bunker C

My point being, Oil burns hot..... Once lit.
PROJECT FARM! WE NEED YOU!

And like I mentioned earlier, if the saw heats up from the added oil, it’s the users responsibility to adjust the screws. No different than cutting in the summer versus cutting in the winter requiring slight adjustments. Added heat causes the tune to go lean and a lean tune causes heat. As long as the flywheel is pumping air and cooling fins are in place, correct ignition timing, acceptable compression, and the fuel isn’t stale, simple tuning is all that’s required to make it run at the right temperature

 

[jellyroll]

Tree Monkey taught me a long time ago to look for a puddle of oil in the crankcase. Just like slightly 4 stroking out of the wood is considered a safe tune, a puddle of residual oil that has trickled into the bottom of the case is a sign that you’re using enough oil. Only makes sense.

Ratio alone isn’t a good method as some oils stay attached better at 50:1 and leave more oil behind than others do at 32:1. Many popular o p e oils leave residual oil like cheap gas station oils, regardless of the Fb, c, d…rating.

Black max oil from walmart leaves a oil film and it does a nice job of cleaning too. It does puddle but nothing like red armor.

 

[MacAttack]

Have you ever thrown a gallon of old motor oil in a fire? Same with a gallon of gasoline? Motor oil is much hotter.
"1 gallon of gasoline = 120,476 Btu. 1 gallon of diesel fuel = 137,381 Btu (distillate fuel with less than 15 parts per million sulfur content) 1 gallon of heating oil = 138,500 Btu (distillate fuel with 15 to 500 parts per million sulfur content)"

GradeHeating Value
(Btu/US gal)Comments

Fuel Oil No. 1132900 - 137000Small Space Heaters

Fuel Oil No. 2137000 - 141800Residential Heating

Fuel Oil No. 4143100 - 148100Industrial Burners

Fuel Oil No. 5 (Light)146800 - 150000Preheating in General Required

Fuel Oil No.5 (Heavy)149400 - 152000Heating Required

Fuel Oil No. 6151300 - 155900Bunker C

My point being, Oil burns hot..... Once lit.
PROJECT FARM! WE NEED YOU!

So is it reasonable to conclude that a given amount of oil actually requires more oxygen molecules to be combusted than the equivalent amount of gasoline? (you can see where I'm going with this...)

 

[MacAttack]

Anyone have a tailpipe O2 sensor? I'd chip in to buy one if someone wants to do some objective testing.

At this point it almost needs to happen haha... I'd absolutely do it except my wife would kill me if I put that much effort into a fuel/air ratio chainsaw science experiment.

 

[OM617YOTA]

At this point it almost needs to happen haha... I'd absolutely do it except my wife would kill me if I put that much effort into a fuel/air ratio chainsaw science experiment.

Looks like air fuel gauges are 35 bucks on eBay. The O2 sensor would have to be mounted on a pipe on the saw and powered by an outside power source.

Hmm.

 

[Smitty Smithsonite]

I get a headache thinking about this ****. I've run Amsoil Saber at 100:1 in customer's and my own saws, trimmers, blowers, and my paramotor for many, many years without ANY oil-related failures. I've seen nothing but benefits. Less mess coming out the exhaust, and less carbon to scrape off pistons and exhaust ports ... oh, and damned near ZERO wear under some very harsh conditions.

Everyone else can do what they feel is right. UNDISPUTED FACT: anything that is not fuel, displaces fuel. AIR displaces fuel. OIL displaces fuel. Moisture / humidity displaces fuel. If this were not true, then fuel screw tweaks would never be needed when ANY of these change.

Flame away!