mixing ratios for 2 stroke chainsaws

[sawmill sam]

I recently had a conversation about mixing ratios for 2 stroke chainsaws and I would like to hear more opinions about it.
I have watched 2 you tube videos that confirm what I have always thought, that more oil causes more heat because it burns hotter than gas.
Here is a link to one of the videos I watched on this subject (by Dave's small engine channel) and I would like to hear what our experts have to say in this forum about this video.
It is a simple and effective method to prove my point that heat levels increase when more oil is used.



thanks in advance and sorry if I'm beating a dead horse here!

 

[bryannewton]

And would it make a difference if the saw was tuned for each fuel for this test

 

[The Shooters Apprentice]

If he’s not turning the saw for each mix, more oil = less fuel = running lean which would make it run hotter.

 

[bryannewton]

That what I was thinking

 

[sawmill sam]

If he’s not turning the saw for each mix, more oil = less fuel = running lean which would make it run hotter.

OK, so when I thought that through it didn't add up to me. When you richen the mix that puts even more oil into the combustion chamber, no matter what the oil ratio is. I still think more oil = more heat no matter how you tune it because oil burns hotter than gas. I will try and locate the other video I watched about this last year.
thanks for the response. I hope more people will "tune in" to this thread!

 

[J D]

Adding more oil displaces a small amount of fuel in the air:fuel mix... less fuel means slightly leaner = slightly hotter & higher rpms. Small changes like oil brand (yes a different brand/type of oil can make a difference too) or slightly heavier mix ratio aren't usually significant. Problems occur when a saw is tuned on the lean side already & a change pushes it over the cusp of meltdown.
My recommendation is to tune for the conditions & the mix you are running.
When choosing a mix, bear in mind that a lack of oil kills thousands of times more motors than carbon build up, & while oil has come a very long way, it has become leaner over time primarily for environmental reasons over equipment lifespan.
Dammit... here we go....

 

[Chevboy0167]

^^^^LOL^^^^

 

[J D]

OK, so when I thought that through it didn't add up to me. When you richen the mix that puts even more oil into the combustion chamber, no matter what the oil ratio is. I still think more oil = more heat no matter how you tune it because oil burns hotter than gas. I will try and locate the other video I watched about this last year.
thanks for the response. I hope more people will "tune in" to this thread!

Fuel does a lot in the way of cooling. Essentially you need enough oil in your fuel to give good lubrication, & enough fuel to slightly exceed the "optimum" air fuel ratio. The additional fuel helps cooling & brings rpm down to mechanical design.
Different oils burn differently

 

[ballisticdoughnut]

Absolutely zero point running 25:1 with a good quality synthetic mix oil. 32:1 is the heaviest I would go and only for a milling application. 40:1 is what I prefer for general use.

 

[Bob Hedgecutter]

How the heck did we ever run anything two stroke prior to the mid 1980's and the introduction of the internet?

 

[Pioneer]

Short answer, depends on your saw and oil.
I see no reason to ever run 25:1 unless you have plain crankshaft bearings in your equipment like some old outboards do. This is 2022, not 1960, and oils have come a long way.
Some oils are set up for 100:1, and this will work fine in equipment that does not have a high power/displacement ratio, although I know of a pro saw run at 100:1 with Opti for decades.
Most are marketed to run at 50:1, and many members have run various brands at this ratio for years with no problems.
A lot of people run 40:1 for the claim of extra engine life and for the extra insurance against scoring the cylinder, it's probably a good idea if you cut wood in hot weather.
The video in the link can be discounted, as people point out you have to re-tune the saw for the change.

Do a search on the site and you will find thousands of posts on oil, the more opinions you gather, the better you are able to make a decision for your application.

 

[The Shooters Apprentice]

OK, so when I thought that through it didn't add up to me. When you richen the mix that puts even more oil into the combustion chamber, no matter what the oil ratio is. I still think more oil = more heat no matter how you tune it because oil burns hotter than gas. I will try and locate the other video I watched about this last year.
thanks for the response. I hope more people will "tune in" to this thread!

your air stays the same, so fattening the saw up gives more fuel to the same amount of air.

 

[Bob Hedgecutter]

your air stays the same, so fattening the saw up gives more fuel to the same amount of air.

Yeah, because air filters never get dirty eh?
Its a Stihl saw in the video- they are well known for dirty air boxes.

 

[rogue60]

What wrong with a hotter tune? most run a blubbering ring sticking carbon producing cold tune thinking it's good lol

 

[rogue60]

OK, so when I thought that through it didn't add up to me. When you richen the mix that puts even more oil into the combustion chamber, no matter what the oil ratio is. I still think more oil = more heat no matter how you tune it because oil burns hotter than gas. I will try and locate the other video I watched about this last year.
thanks for the response. I hope more people will "tune in" to this thread!

Well this is good then if oil burns hotter than fuel that’s a good thing I want a nice hot complete combustion.

 

[grizz55chev]

Well this is good then if oil burns hotter than fuel that’s a good thing I want a nice hot complete combustion.

Fuggin oil threads suck!

 

[cookies]

I run 40-1 or 32-1 however it gets poured, adjust carb as needed before starting to cut due to temperature changes. More oil ='s better sealing capability of the rings raising compression, not necessarily a larger volume of oil retained in the bottom end but the oil retained is exchanged for new oil from the fuel supply more rapidly. Saws use fuel and the fan for cooling, oil ratio has such a tiny impact on temperature it does not even matter compared to lube, sealing and cleaning capabilities.

 

[rogue60]

Fuggin oil threads suck!View attachment 1029590

Join in and learn something for a change..dropping ya bottom lip on the floor because you don't like something ya do know this isn't the what are the best hugs for hurt feelings thread right??

 

[grizz55chev]

Join in and learn something for a change..dropping ya bottom lip on the floor because you don't like something ya do know this isn't the what are the best hugs for hurt feelings thread right??

I've forgotten more than you'll ever know about chainsaws and oil.

 

[rogue60]

I've forgotten more than you'll ever know about chainsaws and oil. View attachment 1029592

That's amazing.