spacemule
The Peanut Gallery
Fixed that for you. :hmm3grin2orange:
Why does everyone run 50:1?
- Thread starter spacemule
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Fixed that for you. :hmm3grin2orange:
B Harrison
ArboristSite Guru
There are plenty of us who will snatch up a fried saw or sell someone a new saw so no biggy.
woodgrenade
ArboristSite Guru
Been running mine at 1:50 for years. It's a little bit of a pain filling up my gas can with 2 gallons of stihl ultra to 5.2 oz of gas but I feel it is definitely worth it for the longevity of my saws.
7sleeper
Addicted to ArboristSite
How does it start? Sometimes a little difficult depending on altitude right? :msp_tongue:
7
stihl023/5
Addicted to ArboristSite
:welcome::deadhorse: 45:1
bucknfeller
Opportunistic Hooligan
:hmm3grin2orange: You are kidding right? What's your stand on limiter caps :hmm3grin2orange:
SawTroll
Information Collector
Your problem. :msp_wink:
Something that many forget is that more oil in the fuel will make the engine run leaner with the same carb settings, as the oil displaces fuel = a leaner fuel to air mix....
almondgt
Addicted to ArboristSite
Oil is cheap. I can afford a bit more to keep my saw protected. That's why I run 60:1.
Appears the fish are biting today. The fisherman got up early to catch the minnows................:hmm3grin2orange:
zogger
Tree Freak
yes, but what is replacing the fuel is actually oil....not just more air. If it was more air like you leaned out the adjustments, yep, would matter a lot, but seeing as how it is oil, the stuff that actually does the lubing, and will combust a little anyway, (to some small degree, big wild card) well..there ya go, it is not going to run significantly hotter at 40:1 over 50:1. And it certainly won't lube *worse*.
The correct ratio would theoretically change constantly, by load/condition/temperature and so on, but we don't have any sort of computer controlled mix oil injected chainsaw two strokes. You would want the most possible lube this side of carboning out or causing sticking rings, whatever, etc. Too little, run too hot, not lube well, too much and it would run like crap if at all. The sweet spot changes in the middle there a lot, but we have no practical way to find that without trial and error really. That 50 to 1 recommended is some sort of compromise that works OK, and also is tied into emissions stuff. And I am really not sure but I think Poulan still says 40:1 with new saws (someone with a new one can chime in here)
By actual anecdotal here, from a lot of guys running a variety of oils and ratios, is anything at all between like 32 to 1 and upwards even a little over 50 to 1, and I bet some of the millers run some pretty heavy oil to fuel ratios.
And I know back in the day, a lot of guys here including myself ran wicked heavy on the oil ratios, using freeking car oil like straight 30 weight dino oil for mix oil. And a lot of times measuring was like this "glug glug glug..looks like enough"! Saws still ran, smoked like crazy, but they ran and cut OK. Not so many toasted pistons and cylinders, just fouled plugs more often.
I was thinking on this some time ago, I honestly can not recall any of my cutting friends ever having a toasted top end, and I know I never did either, back then.
7sleeper
Addicted to ArboristSite
D
Deleted member 83629
Guest
i go by manufacturer specifications regarding what ratio i use 6.4 ounces of husqvarna xp oil to 2 gallons of gas or 40 parts gas to 1 part oil or 40:1
stihl023/5
Addicted to ArboristSite
zogger
Tree Freak
I love that!
7
Ha! What's even funnier is I was still doing it that way until year 2000 something, I think 5? Around there. I knew they had two stroke oil for air cooled small engines, just I was still cruising on the "if it ain't broke, don't fix it" mentality. And no one told me any different. Ignorance can sometimes be..well, not bliss, but it won't be *that* bad...
I use synthetic now and measure it, just saying, I bet most saws would still run fine doing it the old way. It's just real smoky and stinky doing it like that.
This is even MORE funny!! Jusr now saw some coincidental proof! I just got back in from air blowing off an old carcass that is going out as my christmas give away here. I was dumping out the mix and bar oil side (mostly empty on inspection). You can definitley tell on the mix side, whenever I parked this thing, that I was using car oil for mix oil. The engine was running fine when parked, I do remember that, just it leaked bar oil (again, the same car oil no doubt) and the AV was shot, etc. Right after that saw is when I started using proper mix oil and bar oil, as I went and bought a new (cheapest husky at the time) one and they sent me home with a jug of bar oil and some mix oil little jug.
7sleeper
Addicted to ArboristSite
I've done it also. I was at my FIL place and the 4 stroke lawnmower was broken down, so he says go in the basement and carry out the red one. (He has about 1/2 dozen very old models, he used to go to the junkyard regularly and get some real cool stuff, Stihl Contra, 041). An old Sachs 2 stroke with at least 125cc. Didn't have any 2 stroke oil around so just got some engine oil and the "glug glug" technique. Man that thing started up and what a hurricane. That thing was scary! Vibration incredible but everything was wiped out at least 1 meter! It's my favorite lawnmower now.
Have to do some fiddling around next time at his place.7
zogger
Tree Freak
I've done it also. I was at my FIL place and the 4 stroke lawnmower was broken down, so he says go in the basement and carry out the red one. (He has about 1/2 dozen very old models, he used to go to the junkyard regularly and get some real cool stuff, Stihl Contra, 041). An old Sachs 2 stroke with at least 125cc. Didn't have any 2 stroke oil around so just got some engine oil and the "glug glug" technique. Man that thing started up and what a hurricane. That thing was scary! Vibration incredible but everything was wiped out at least 1 meter! It's my favorite lawnmower now.
7
BWAHAHAHAHA! Skeeter fog!
beerbelly
Mouth breather
My old Mac 10-10 was the "glug glug" method for the fuel, 30w or 10w40 or whatever I had at the time for the bar. Saw ran great. Cut a lot of wood. Cost me a six pack & $20. Now that I dish out 4+ bills for a medium size saw, I am only running straight diesel!! I figure that way it will be plenty lubed. Heck, The old Detroit diesels were 2 stroke, must work for a chain saw too. Couldnt kill them. Kidding!!!! Dont take it serious. Only use a gas/mix in your saw..dont try this at home, ask your doctor if it is right for you....side effects may include...... (lawyer talk!)
SawTroll
Information Collector
I wouldn't gamble on that, as the fuel actually is the main coolant.....
SawTroll
Information Collector
No problem haven't lost one yet. And they are adjusted just fine.
I didn't say it was a major issue, specially not if the carb is adjusted accordingly! :smile2:
zogger
Tree Freak
Well, not sure on that, cold air coming in constantly with each stroke, and cool air being pumped over the fins is a pretty important coolant. If it was primarily and/or just the mix..no need for fins or the flywheel fan pumping air over them. I mean, anyone can try this to see which is more important or not, go ahead and bust the fins off the cylinder and flywheel and run it hard with the "correct" fuel oil mixture and tune and see how long the saw lasts.
It's all important really. You need all of the above.
The fuel mix and oil mist absorbs and moves out *some* of the heat in the exhaust, and the oil in the mix-mist helps reduce the heat at the friction level, which is considerable. Very important job there. So both liquids in the mix contribute to cooling. As do the wet oil soaked chips being slung out helping to keep the bar cool, which helps over all with keeping the whole saw cooler.
I know a rich mix runs cooler, because a ton of those long chain hydrocarbons in the mix aren't burnt, they go in and out still intact, so they act as a heat transfer more than a heat generator. It's real precise there the dividing line between "enough" and "whoops"!
EPA strangled "lean" adjustments burn more mix (a more thorough complete burn), but cause more heat, but have less emissions, because the mix is actually burnt and not just pumped in and out. They have decreed that emissions are more important than saw cooling and running, and that's just that. Cats get hot to burn even more, but it stops the good flow of heat out. Lotta compromises going on there for a simple engine.
I *think*, but do not know (any thermodynamic engine guys here can confirm or deny), that if you didn't care about weight, you could run much larger cylinders as to exposed in fin area, making a much heavier saw, along with better ducting and flywheel cooling, and get by with stock higher compression and a leaner more efficient tune (Power and feet of chain pulled per tank, or "mileage"), without sacrificing engine robustness and longevity. Sucker would be much bulkier and heavier though, and most likely need different dimensioned pistons and stroke (given shooting for the same displacement, and compression much closer to the diesel range for example). Dang you'd need some stout bearings and cranks and so on as well. And stout fingers arms and shoulders to start that puppy.
maybe one of the hotsaw builders might chime in here, as I am now technically over my head.
