Facts reguarding gas to oil ratios????

[Ianab]

Both times that I've bought new chainsaw (Stihl & Dolmar) I've been told by the dealer to ignore the manual, and mix the oil 25:1. Reason given was that NZ fuel is refined differently, and although the octane rating is the same, the chemical mix is different.

Anyway, the local distributors figured they got less warranty returns if they told us to run more oil. Now maybe with European or US fuel the saws are OK at 50:1, but locally the saws are run ~25:1. So the idea that more oil kills saws is a bit dubious?

Official, made in NZ, Dolmar oil that came with the saw
   

So no scientific facts, just my experience, that I mix my fuel at 30:1, with a brand name oil, for everything, and they don't blow up. 3 x Chainsaws, lawnmower, weed eater etc. I don't seem to foul up spark plugs, engines are tuned for the fuel mix I'm using, and all is well.

Ian

[Al_Smith]

 :D Hoorray for the oils wars .The great debate will live forever .

[Al_Smith]

BTW that's the first shot of a 441 piston I've ever seen .By the time a "new" innovation comes my way it will be old .I almost had one last summer but all it was was a spark plug that rattled loose .

By the looks of that piston and crank it looks like the oil broke down,pyralited ,started to burn off to petrolium coke .Not good .

[Little Al]

 
Not chainsaws I know, but never the less air cooled 2 stroke motors . If you read some of the tuning books [mainly for Go Kart & Motor Cycle motors] the dyno results & checks on strip down [ mostly based on mineral oils] prove that the more oil you pour into the fuel [within reason] the motor will run harder & produce more  power [ a good example is Graham Bells book] from my days of motor cycle road/track racing using both air & liquid cooled 2 stroke it seemed to get more of a contest of who could use the least oil/fuel ratio than who won the race. for saws I`m with the not less than 32/1 ratio

[Rob5073]

If anyone is interested, I found a oil ratio calculator that is pretty slick. Can do standard or metric conversions.

www.csgnetwork.com/oilfuelcalc.html

[NCFarmboy]

These links completed the story for me.  Been doing 32-1 for years never blown a 2 stroke or had a bearing go bad.  EHP reports the Husky 385 with crank brg failure @ 50-1 (385 is famous for that) no bearing failures on 385-390 w/woods port @ 32-1. 
Been using this breakin procedure since 1964 on all engines.  Started building hot rods whenI was 16.
As Al said oil wars never end but the eternal peace agreement has been settled for me 32-1 premium nonE gas 1 oz Seafoam or Startron.  Tuned for that mix.  Tuning is the key.
Shep

http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf
http://www.mototuneusa.com/break_in_secrets.htm

[The Ripper]

I like my oil ratios around 40/1,with these 2 cycles turning such high RPMs,you need the extra lubrication for parts longevity, to absorb heat and  to  spread this dissipation process. I just don't see the benefits of synthetics oils over conventional oil,except for cost investment.     

[ZeroJunk]

I started out with a Homelite 7-19 mixing a half pint to the gallon. That must have been really lean.

[shootingarts]

These links completed the story for me.  Been doing 32-1 for years never blown a 2 stroke or had a bearing go bad.  EHP reports the Husky 385 with crank brg failure @ 50-1 (385 is famous for that) no bearing failures on 385-390 w/woods port @ 32-1. 
Been using this breakin procedure since 1964 on all engines.  Started building hot rods whenI was 16.
As Al said oil wars never end but the eternal peace agreement has been settled for me 32-1 premium nonE gas 1 oz Seafoam or Startron.  Tuned for that mix.  Tuning is the key.
Shep

http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf
http://www.mototuneusa.com/break_in_secrets.htm

Gotta comment about the Bridgestone test. Back in the seventies we ran a pretty stout short track V-8 engine. I don't know about dyno's now, but back then each one was a law unto itself. All you really got was a comparative horsepower reading to other things you tested on the same dyno. Being old friends our driver was able to get our engine tested on Bobby Allison's dyno. Bobby's engine tested at 540HP, ours at 580. What does this have to do with the price of tea in china or the test using bean oil?

We were one of the only two short track teams I ever saw running bean oil. Enough of the oil went by the four cycle rings and valve seals, don't actually know where, to clean out your sinuses if you were around the exhaust long. There were very strong indications that adding bean oil to the racing gas ran in that car added horsepower.

The above just to explain I would fully expect adding more bean oil until reaching a tipping point to add horsepower to any gasoline engine including two cycle saws. I think Bridgestone ruined their test just as they feared some people would believe. Probably have to run the test with the particular oil you are running for it to be totally valid, I don't buy the idea that oil doesn't burn at all which is what they seem to state. If it burns it releases energy. How much is the question.

It does seem kinda odd that we burn high octane gas which is cooler then put the least possible oil in it to keep it "hotter". My current and future plans are premium no alcohol gas, xylene, and semi-synthetic or synthetic oil at or very near the design mix of 50-1. Not sure if what I am burning now is full synthetic but that is where I think I am headed.

Hu

[clww]

I run a ratio of about 40:1, only ethanol-free 93 octane as long as I can still get it.

[John R]

I use 91 octane ethanol free, with Stihl Ultra at 50:1, never a problem.
The Ultra must be good mix oil, Stihl gives an extra year warranty if you buy a 6 pack at the time of saw purchase.

[AdkStihl]

I use 91 octane ethanol free, with Stihl Ultra at 50:1, never a problem.
The Ultra must be good mix oil, Stihl gives an extra year warranty if you buy a 6 pack at the time of saw purchase.

The average homeowner Joe isn't gonna burn 6gal of mix in 2 summers. That deal makes the average person feel all warm and fuzzy.
Yes, it is good oil, but smells like 7!@#%^&*.

Wheres the "Like" button?   

[ZeroJunk]

I use 91 octane ethanol free, with Stihl Ultra at 50:1, never a problem.
The Ultra must be good mix oil, Stihl gives an extra year warranty if you buy a 6 pack at the time of saw purchase.

I was thinking it had to do with valve problems on the 4-Mix stuff. Ultra burns much cleaner.

[chucker]

I do believe all my 2 cycle saws need a valve job or new muffler bearings....

[Bret4207]

I use a 50:1 oil.....it works well for me.

Carthage, New York



I see your location is Northern NY. Whereabouts if you don't mind me asking?

Hitech, I'm just north of Gouverneur.

Back when we had the Husky/Jred dealership I went over to Tiltons HQ in NH and took some classes with their chief mechanic at the time, a guy named Del Leech (sp?) IIRC. At that time they were claiming that anything richer than 50-1 would heat up the crank bearings. So I went with 50-1 for my own saws for quite some time. Meanwhile, we had guys running everything from the latest 266/181/2100's to 041 era Stihls to 7-10 and older 300 Macs to Pioneer P51's and 60's, Homie 925's and XLs, even a few Remingtons and the odd Partner or Poulan. A lot of those guys had 5 or 6 makes covering 30 years. They'd run everything on one mix- it might be 20-1 using 30 wt with one guy, 40-1 with Stihl oil with another, 50-1 Husky oil with a 3rd. Most were down around 30 or 35-1 if they had a real mix of saws. Yes, we had some scored jugs and bad pistons that we could almost always trace to dry gas use or guys leaning them way out, but we never, ever had bad crank bearings and only 2 wrist pins failures I can recall. OTOH, I seized up 2 of my own saws and an ancient 2 stroke tiller that called for 16-1 that I was running 35-1 in to cut down on the smoke. I have since decided that 35-1 is where I'm going to stay. I know guys using this 100-1 mix that swear by it, but they don't cut a full cord in a year. I'm too cheap to turn another saw into toast.

[MidWestTree]

I love a good oil thread! If there's one thing that stuck with me over the years from science class it's do things in groups of three to get a "test" group, or something to that effect.

What we need are deep pockets, one good quality oil and a test lab with a bunch of the same brand new saws to test under load and time to see what mix gives the best longevity and what the line in the sand is for early failures.

You know the manufacturers have done it, and they aren't sharing those results.

[chucker]

"LIKE"(up one)

[Al_Smith]

I've ran Stihl ultra also but instead of mixing it with 2.5 gallon for a 50 to 1 ratio I dump in 2 gallons whatever that comes out to .More than likely it's actually maybe 1.8,1.9 gallons because I never fill the can to the brim .I have a tendency to spill it if I do .

Lawdy I've got about 2 5 gallon buckets full of those little jugs .What I'm saving them for I have no idea .Pack rat maybe . ;D

[ZeroJunk]

I do believe all my 2 cycle saws need a valve job or new muffler bearings....

Not sure whether you were making a joke about my post, but Stihl 4-Mix weedeaters, blowers, pole saws, do have valves and the oil is mixed with the fuel.

[chucker]

 ;D don't throw a valve retainer, im just pulling your string to let you know stihl is messing with a tried and true 2 cycle system that works.... lol if its not broken ? find something g else to fix/wreck! :laugh:

[thecfarm]

Al,I throw mine away. And I keep ALOT of stuff too.  :(  I use the Husky mix. I take one of the so called 5 gallons little mix jugs of oil and put it no more than 4 gallons of high test into it,40:1 This time of year I put one on the shelf of the OWB over night to warm it so I get very bit of oil out of it.

[Al_Smith]

Ha jugs .I used to use old anti freeze jugs for saw gas until I anti freezed a weed wacker and almost gassed a radiator .The mix gas and the anti freeze were almost the same color ---oops .

[HiTech]

I use a 50:1 oil.....it works well for me.

Carthage, New York



I see your location is Northern NY. Whereabouts if you don't mind me asking?

Hitech, I'm just north of Gouverneur.

Back when we had the Husky/Jred dealership I went over to Tiltons HQ in NH and took some classes with their chief mechanic at the time, a guy named Del Leech (sp?) IIRC. At that time they were claiming that anything richer than 50-1 would heat up the crank bearings. So I went with 50-1 for my own saws for quite some time. Meanwhile, we had guys running everything from the latest 266/181/2100's to 041 era Stihls to 7-10 and older 300 Macs to Pioneer P51's and 60's, Homie 925's and XLs, even a few Remingtons and the odd Partner or Poulan. A lot of those guys had 5 or 6 makes covering 30 years. They'd run everything on one mix- it might be 20-1 using 30 wt with one guy, 40-1 with Stihl oil with another, 50-1 Husky oil with a 3rd. Most were down around 30 or 35-1 if they had a real mix of saws. Yes, we had some scored jugs and bad pistons that we could almost always trace to dry gas use or guys leaning them way out, but we never, ever had bad crank bearings and only 2 wrist pins failures I can recall. OTOH, I seized up 2 of my own saws and an ancient 2 stroke tiller that called for 16-1 that I was running 35-1 in to cut down on the smoke. I have since decided that 35-1 is where I'm going to stay. I know guys using this 100-1 mix that swear by it, but they don't cut a full cord in a year. I'm too cheap to turn another saw into toast.

I remember one time I bought a 340 Homelite and they gave me 16:1 oil for it. I didn't cut 3 cord of wood and it was plugged up. I switched to 50:1 mix and started it up. It farted and coughed and sneezed for awhile and then ran better than ever. I still have this saw...it is my lender now. Starts with one pull. Anyone who wants to borrow a saw gets this one. lol Normally when it is returned you can't figure out if they were cutting concrete with it or wood. lol Sometimes I can save the chain by sharpening it and sometimes I just throw it away. Normally people who borrow a saw don't have many skills when it comes to using one. I always fill the saw with gas and oil and give them a pepsi bottle with gas and a pepsi bottle with bar oil and very seldom do they use them. They don't cut much but must have fun doing it. lol

[angelo c]

My favorite ratio is 1/3 stihl tuning screw driver....used correctly
1/3 sharp chain
1/3 sharp operator
1/3 sumkindaoil in the mix....and i keep all my fuel in a temperature consistent environment when unused. 

[Rob5073]

I'm enjoying reading this thread.  So what I'm gathering is the safe mixture zone is generally from 32:1 to 50:1 and a frequent user prefers more oil in the mix than an infrequent user like myself.  It would seem like an ideal mix would be 40:1 but i suppose that is dependent on the motor.  The saws I have ask for 50:1 and I have pre-measured Stihl ultra (50:1) in the 2.6 oz bottles. After reading this I'll probably just start mixing one bottle to 0.85 gallon of gas and call it good.