Oil questions...

[Al Smith]

The great oil debate never dies .---enough said --

 

[hacskaroly]

The great oil debate never dies .---enough said --

I tried to redirect it to an existing thread

 

[Fabulous]

I guess it depends on the build. I’ve tried running 32:1 and unless I’m working the heck out of the saw it seems to accumulate more carbon than 50:1 - IT could be the fuel itself is causing this. While pricey, the canned motomix alkylate fuel has served me very well and I use it on my smaller (40-60cc) saws. Obviously running a 395xp on it will cost an arm and a leg so IF I have a lot of large bar work (up to 5gal) I will use pump gas and mix my own. After I’m done I’ll drain the remainder and fill 1/2 way with the motomix and run it for a few minutes to “flush” out the pump fuel. I’ve noticed FAR fewer issues doing it thus way especially if the saw is going to sit on the shelf for weeks or months until it’s next use

 

[RCBS]

I used to refer to 'heavy' oil as running 'rich'. An old dirtbike mechanic corrected me. Increased oil means less fuel. This is when I realized that you can adjust the tune of a 2T by the screws or by the amount of mix added to oil. He explained that certain bikes he tuned 'rich' with the jetting and allowed 40/50:1 mix ratios and others would tune better using oil to lean the fuel 20/32:1 while using larger jets. It's not just conjecture on his part either. Everyone around here knows he's the guy to take your bike to if you have a fueling issue needing sorted or you just want it to run as well as it can, in it's current state.

 

[bwalker]

I guess it depends on the build. I’ve tried running 32:1 and unless I’m working the heck out of the saw it seems to accumulate more carbon than 50:1 - IT could be the fuel itself is causing this. While pricey, the canned motomix alkylate fuel has served me very well and I use it on my smaller (40-60cc) saws. Obviously running a 395xp on it will cost an arm and a leg so IF I have a lot of large bar work (up to 5gal) I will use pump gas and mix my own. After I’m done I’ll drain the remainder and fill 1/2 way with the motomix and run it for a few minutes to “flush” out the pump fuel. I’ve noticed FAR fewer issues doing it thus way especially if the saw is going to sit on the shelf for weeks or months until it’s next use

Tuning issue.

 

[bwalker]

I used to refer to 'heavy' oil as running 'rich'. An old dirtbike mechanic corrected me. Increased oil means less fuel. This is when I realized that you can adjust the tune of a 2T by the screws or by the amount of mix added to oil. He explained that certain bikes he tuned 'rich' with the jetting and allowed 40/50:1 mix ratios and others would tune better using oil to lean the fuel 20/32:1 while using larger jets. It's not just conjecture on his part either. Everyone around here knows he's the guy to take your bike to if you have a fueling issue needing sorted or you just want it to run as well as it can, in it's current state.

The differance between 50:1 and 25:1 is less than one jet size in a bike. Temperature has a much greater effect.

 

[Fabulous]

Tuning issue.

Please elaborate

 

[bwalker]

Please elaborat

There isnt much to elaborate on. If you're tuned rich you will burn dirty. Also using a high viscosity, high temp oil doesn't help either.

 

[Fabulous]

If you’re tuned rich on the h,l circuits it’ll burn dirty whether you are at 50:1 or 32;1! A gallon at 50:1 is 130.6 oz total , at 32:1 you would have 132 oz total. If you were tuned correctly at 32:1 then switching to 50:1 will require a slight adjustment of the needles and vice versa. Ive noticed the motomix seems to make a properly tuned 50:1 (on pump gas) saw run a fuzz leaner -most likely because it’s a more pure fuel without all the benzene toluene and aromatics added to pump gas. I have manual carb saws and mtronic / autotune saws - I prefer the latter

 

[Outback]

32 vs 50 to 1, is a 1 percent difference in fuel energy. 50 vs 100 to 1, is a 1 percent difference in fuel energy. e10 is 3 percent less fuel energy than non ethanol. The difference in your oil mix is more than 3 times less relevant than whether you use ethanol fuel or not as regards the tune.

@7000ft your at 75% sea level air density so a variation of 280ft of altitude on average will equate to 1 percent of your oxygen on the other side of the curve. Using ethanol vs non ethanol equates to an almost 1000ft variation in altitude as regards the perfect tune.

Tuning by oil mix ratio is perhaps the most dubious thing I've ever heard. If 1 percent makes a noticeable difference you're way to lean or way to rich and shouldn't be tuning anything. If your gonna worry about your oil ratio affecting tune start considering your fuel, your altitude and if you're really nuts the temperature and humidity.

 

[59billy]

32 vs 50 to 1, is a 1 percent difference in fuel energy. 50 vs 100 to 1, is a 1 percent difference in fuel energy. e10 is 3 percent less fuel energy than non ethanol. The difference in your oil mix is more than 3 times less relevant than whether you use ethanol fuel or not as regards the tune.

@7000ft your at 75% sea level air density so a variation of 280ft of altitude on average will equate to 1 percent of your oxygen on the other side of the curve. Using ethanol vs non ethanol equates to an almost 1000ft variation in altitude as regards the perfect tune.

Tuning by oil mix ratio is perhaps the most dubious thing I've ever heard. If 1 percent makes a noticeable difference you're way to lean or way to rich and shouldn't be tuning anything. If your gonna worry about your oil ratio affecting tune start considering your fuel, your altitude and if you're really nuts the temperature and humidity.

I think that at the end of the day, tuning needs to be about what the saw is doing in the moment. Whether its affected by altitude, oil mix, ambient temperature, ethanol or whatever is interesting as a scientific wank, but that's about it. Keep that screwdriver in your pocket and listen to the saw. Feel the saw. Be the saw.

Okay, ignore the last two sentences.

 

[bwalker]

If you’re tuned rich on the h,l circuits it’ll burn dirty whether you are at 50:1 or 32;1! A gallon at 50:1 is 130.6 oz total , at 32:1 you would have 132 oz total. If you were tuned correctly at 32:1 then switching to 50:1 will require a slight adjustment of the needles and vice versa. Ive noticed the motomix seems to make a properly tuned 50:1 (on pump gas) saw run a fuzz leaner -most likely because it’s a more pure fuel without all the benzene toluene and aromatics added to pump gas. I have manual carb saws and mtronic / autotune saws - I prefer the latter

We dont add aromatics to pump gas...we take them out in fact.
Some of the cand fuel actually has aromatics. Benzene, Toluene and Xylene are all aromatics BTW.
The problem with motomix is its mixed with Ultra oil. No thanks.

 

[bwalker]

I think that at the end of the day, tuning needs to be about what the saw is doing in the moment. Whether its affected by altitude, oil mix, ambient temperature, ethanol or whatever is interesting as a scientific wank, but that's about it. Keep that screwdriver in your pocket and listen to the saw. Feel the saw. Be the saw.

Okay, ignore the last two sentences.

This is spot on and a reason why Autotune and Mtronic are very beneficial to the average guy.

 

[bwalker]

32 vs 50 to 1, is a 1 percent difference in fuel energy. 50 vs 100 to 1, is a 1 percent difference in fuel energy. e10 is 3 percent less fuel energy than non ethanol. The difference in your oil mix is more than 3 times less relevant than whether you use ethanol fuel or not as regards the tune.

@7000ft your at 75% sea level air density so a variation of 280ft of altitude on average will equate to 1 percent of your oxygen on the other side of the curve. Using ethanol vs non ethanol equates to an almost 1000ft variation in altitude as regards the perfect tune.

Tuning by oil mix ratio is perhaps the most dubious thing I've ever heard. If 1 percent makes a noticeable difference you're way to lean or way to rich and shouldn't be tuning anything. If your gonna worry about your oil ratio affecting tune start considering your fuel, your altitude and if you're really nuts the temperature and humidity.

Your energy figures must not be including the energy present in the oil, which has a higher BTU number than gasoline.

 

[Outback]

Agreed. Where I used to cut the most is 2400ft higher than my house. A little tickle on the screwdriver mattered. The oil ratio not so much.

walker, You are correct, however, If you think about it that means there is even less than a percent of difference if its burning the oil. I've been told though that chainsaws don't have the compression to burn the oil for power so who's to say. The point is it is at best a 1 percent difference at worse a fraction of a percent were talking about so I stand by my point that it doesn't matter. Unless of course your chasing that last .05 hp..... Give or take.

 

[Fabulous]

We dont add aromatics to pump gas...we take them out in fact.
Some of the cand fuel actually has aromatics. Benzene, Toluene and Xylene are all aromatics BTW.
The problem with motomix is its mixed with Ultra oil. No thanks.

The canned fuel like motomix is 99.99% alkylate fuel - it’s simply the finest fuel you can run and has a shelf life of 2years. Iirc motomix has 10 chemicals in it vs over 100 for pump fuel and those 90 are toxic as heck! It also has more btu per gallon than pump fuel … Dukes in PA has aspen fuel available afaik and you can use your favorite mix oil if STIHL ultra isn’t to your liking

 

[huskihl]

I guess it depends on the build. I’ve tried running 32:1 and unless I’m working the heck out of the saw it seems to accumulate more carbon than 50:1 - IT could be the fuel itself is causing this. While pricey, the canned motomix alkylate fuel has served me very well and I use it on my smaller (40-60cc) saws. Obviously running a 395xp on it will cost an arm and a leg so IF I have a lot of large bar work (up to 5gal) I will use pump gas and mix my own. After I’m done I’ll drain the remainder and fill 1/2 way with the motomix and run it for a few minutes to “flush” out the pump fuel. I’ve noticed FAR fewer issues doing it thus way especially if the saw is going to sit on the shelf for weeks or months until it’s next use

Has more to do with the tune and the individual oil. If you’re making carbon and you didn’t like it, switch to something else. The pics in post 27 show that

 

[bwalker]

The canned fuel like motomix is 99.99% alkylate fuel - it’s simply the finest fuel you can run and has a shelf life of 2years. Iirc motomix has 10 chemicals in it vs over 100 for pump fuel and those 90 are toxic as heck! It also has more btu per gallon than pump fuel … Dukes in PA has aspen fuel available afaik and you can use your favorite mix oil if STIHL ultra isn’t to your liking

Motox mix may be 99.99% alkylate, but others are not.
Its mixed with Ultra oil, which is garbage so its not the finest.
I am well aware what pump gas has in it and what alkylate is. I make the stuff for a living.
VP, Harvest King, True Fuel and others all sell canned fuel without oil in it that you can mix yourself.
In a two stroke Its somewhat beneficial to have a few other components than straight alkylate.
The other thing is alkylate is a toxic chemical, which you dont seem to be aware of. Attached is an MSDS for alkylate.

 

[Fabulous]

… I’ve been using the Stihl ultra for over 25 years now. Buck over 100/face per years plus treework. Everything runs well and engine is clean as a whistle. Are there better mix oils out there? Perhaps , I don’t see a reason to change my ways at this stage of the game tho … I guess ya just pick an oil/ratio and stick with it right?

 

[bwalker]

Agreed. Where I used to cut the most is 2400ft higher than my house. A little tickle on the screwdriver mattered. The oil ratio not so much.

walker, You are correct, however, If you think about it that means there is even less than a percent of difference if its burning the oil. I've been told though that chainsaws don't have the compression to burn the oil for power so who's to say. The point is it is at best a 1 percent difference at worse a fraction of a percent were talking about so I stand by my point that it doesn't matter. Unless of course your chasing that last .05 hp..... Give or take.

A properly tuned saw burns oil just fine or you would have a mess in your muffler and even worse internally.
A 20 degree swing in temperature has way more affect than oil....and guys aren't tuning for that either, which is why dealers set the things pig rich in many cases.