Mix ratio -- observing the blue smoke

[husqORbust]

Hey, question about mix ratio, and how it changes the smoke output, and/or if smoke output is a relative thing to base lubricating ability.

I mix at 50:1 with Stihl conventional oil(white bottle mix, Canada) and I've been skeptical on it's lubrication ability with how much smoke is emitted. I've also ran motomix, and also not much smoke comes out. Then I see guys' saws pouring out blue smoke....gives me that warm fuzzy feeling that things are being adequately lubed. No idea their oil type or mix ratio.

Is 50:1 really just "good enough" and is fueled by an emissions stand point? Emissions and BS aside, should I run a heavier oil mixture?
Does a lack of blue smoke necessarily suggest under lubrication?

 

[Andyshine77]

It has to do with how the saws carb is tuned much more than the mix ratio. I mix my oil @ 32:1 and only see a puff of smoke at startup, after that pretty much nothing.

 

[holeycow]

It also has very much to do with the brand or type of oil; more during running than at startup. Imo, there should be a decent amount of smoke at startup with any oil and then almost none perceptible when warmed up with properly formulated oils for the type of 2 smoke engine it's in.

ps, there is no reason to run a lean oil mix. Get as much oil and fuel through the thing as possible. More fuel, more power; more oil, more lubrication and better ring seal to combat blowby which builds deposits on the piston sides.

anyway...

 

[SawTrash]

. More fuel, more power; more oil, more lubrication

More oil, leaner fuel to air ratio....

 

[sean donato]

More oil, leaner fuel to air ratio....

That's why you have needles to adjust the carb.

 

[PV Hiker]

9 years I ran 50:1 Stihl synthetic oil through a Stihl MS362. 9 years of solid no worries usage. Sold it last month and gave it a look and the piston and cylinder still looks as it was new. Granted that was with proper saw use and maintenance. Use oil and ratio what you are comfortable with and I agree with all that was said above my post. Cheers.

 

[Okie]

It has to do with how the saws carb is tuned much more than the mix ratio. I mix my oil @ 32:1 and only see a puff of smoke at startup, after that pretty much nothing.

AMEN

 

[husqORbust]

More oil, leaner fuel to air ratio....

I read that as two statements... "more fuel, more power" or "more oil, more lube" pick your poison.

Guess this is a 6 of 1 half dozen of the other if blue smoke doesnt mean proper lubrication. Based on what you guys are saying I suppose the condition of the engine after a given period of time is more an indicator of it being lubed properly or not rather than judging the blue smoke.

Back in the day when I was playing around with nitro RC's a healthy tune was indicated by still having a blue smoke trail under full throttle... suppose thats not the case with chainsaws.

Andy, is there a particular reason/incident you run 32:1?

 

[toadman]

I normally see a little when it's cold, but after the tool warms up very little to none on my properly tuned machines with good fuel.
oil should burn fully in combustion with the fuel, and that means little to no visable smoke.
Smoke under full temp/throttle in newer saws means you're building carbon typically, bad oil type, or something else is out of whack.
I had a homelite super 2 given to me as a young teenager that blasted clouds of oil under all RPM and load at 50:1... it ran great for years off and on climbing, firewood, ect. 100's of hours, zero maintenance on my part, but had a leak between the carb and cylinder the whole time that caused me to tune it rich to compensate, hence the smoke.
I finally fixed it & it has never smoked since, not that I use it much.

 

[Okie]

Also:
Comb your hair before going into the woods.
You might be mistaken as Bigfoot (Darrel) with a chainsaw.

 

[Ted Jenkins]

The previous AS people are correct as tune is important. For more than forty year have always run 34:1 especially my race engines and never plan on a change. With race motors carburation is a very specific tune set up for each RPM range. On Chain saw tuning it is a combination of H and L over lapping each other. Thanks

 

[BradSt]

Generally, smoke comes from an excessively rich fuel/air mix. 32:1 won't smoke, if the tune is correct. With more oil, I do notice more "smell" from the exhaust.

Nitro RC engines run on a mix of oil, methanol and nitromethane. That requires a very rich fuel/air ratio for proper combustion (compared to gasoline), and to keep the ringless piston from seizing. Also, combusting methanol releases a significant amount of water vapor, which increases the appearance of "smoke".

More oil offers a few things...better ring seal, better protection of the moving parts when in use, and more left over oil inside the engine, to protect against corrosion during storage.

 

[husqORbust]

Also:
Comb your hair before going into the woods.
You might be mistaken as Bigfoot (Darrel) with a chainsaw.

Hahaha

Nitro RC engines run on a mix of oil, methanol and nitromethane. That requires a very rich fuel/air ratio for proper combustion (compared to gasoline), and to keep the ringless piston from seizing. Also, combusting methanol releases a significant amount of water vapor, which increases the appearance of "smoke".

Interesting....did not know that.

 

[Miles86]

Hey, back when I was in high school, we all used Belray mc1 in a round pint bottle. LOTS of blue haze. I read that the oil companies used a base oil called bright stock, now they use a base called PIB, a type of ester . Less haze and clean burning.

 

[kevin j]

Base stocks and additives are way different now than 20-30 years ago. 2 cycle motorcycles left a cloud, now the same vintage motorcycle on modern oils is just a haze, barely visible sometimes.

 

[Andyshine77]

Hey, back when I was in high school, we all used Belray mc1 in a round pint bottle. LOTS of blue haze. I read that the oil companies used a base oil called bright stock, now they use a base called PIB, a type of ester . Less haze and clean burning.

BIP is more of an additive than a base stock. It does replace bright stock that were once used to keep film strength up.

 

[KASH]

Truest thing I have heard in awhile.
Low and high speed jets have to over lap each other thre has to be a smooth transition from low to high

 

[North by Northwest]

Base stock oil has been around for years . As a group I oil (solvent neutral) it is comprised of parifin wax to provide viscosity enhancement . Many newer Group II & III base oils are now in production where lighter viscosity usage is required to meet application requirements . Bright Stock is more used today in Heavy Industrial or Marine oil or automotive gear case oil applications . 50:1 two cycle oil mixtures are the norm today with the new Synthetic oils . 40:1 or 32:1 are designed more for extreme or racing applications today , or back in the day when inferior oil technology required much more oil to provide the lubricity and viscosity index to protect metal surfaces within the engine . Today as has been mentioned , numerous additives are available in application specific oils on the market !

 

[holeycow]

50:1 is not the norm for anyone who knows wtf they are doing with their 2 stroke.

 

[North by Northwest]

50:1 is not the norm for anyone who knows wtf they are doing with their 2 stroke.

holeycow wtf are you sniffing , majority of saw manufacturers including Husquarna , Stihl & Dolmar recommend 50:1 fuel to oil ratio . I have ran everything from Snowmobiles & dirt bikes to saws , trimmers & blowers for over 30+ yrs with no issues @ 50:1 with numerous premium synthetic oils . Most recently switched to FD rated Maxima K2 . As I mentioned in extreme usage I have ran 40:1 in Racing applications with. conventional mineral oils with air cooled dirt bikes and snowmobiles only . I believe my life experience at age 65+ and the big 3 saw manufacturers recommendations out weigh your thin air high elevation rational out West , within today's premium synthetic oils today :****you: