This is probably not "analytical" enough, but my theory is that the 20:1 ratio that you used "back in the day" simply isn't needed now because the quality of the product (the oil) is so much improved. If 50:1 is enough to provide adequate engine protection and is more environmentally friendly (and less expensive)...why not use it? I use 50:1 in my Toro snowblower with no trouble at all. I don't know if 32:1 or even 20:1 would be better, but I suspect that any benefit gained wouldn't be enough to be worth the bother.

My 1974 LB mod. 7263, calls for 16/1 mix. So does this
mean that if I use modern oil I can cut it down to 50/1?
The idea scares me.

"What happened to the technology back in the olden days"

That wasn't technology. More oil was needed because of looser tolerances and poorer oil. Like someone said above, modern oils are much higher quality. Also, modern machining technology provides higher precision surfaces and tighter tolerances.

To the poster that wondered about putting 50:1 in his 1974 LB, no, don't. You still need a richer mix, but 16:1 is not necessary. 32:1 should be fine.

"My 1974 LB mod. 7263, calls for 16/1 mix. So does this
mean that if I use modern oil I can cut it down to 50/1?
The idea scares me."

The OP was asking about using more oil than 50:1 in a new engine, and I advanced a guess as to why it was not necessary. I certainly do not mean to suggest that a 33 year old LB should start using 50:1 if it was not recommended.

I am glad to get response so quickly. My goal is to stir up some logical thinking so we can all benefit from this. I have been an electrical engineer for 30 years and throughout the years I heard enough myth in my field about doing things ( or not to do things )certain ways and it turn out to be a myth or by someone back in the older days said so and people take it by heart.

Azinoh mensioned about improvement of oil. This I totally agree. I know for fact that oil has improved tremendously in the past 20 years from knowledge of the autos. There had been tests do by Popular Science dated back in the early 80's about synthetic oil advantages and so on. I agree in this end, it is better and you can get away with much less oil. BUT 50:1 is very very little oil!!! It is like running the engine for 30 minutes on one TEASPOON of oil ( 2.6 oz oil per gallon is like one teaspoon per tank!!!). I know the new engines have chrome plated cylinder wall and even crankshift, but a little bit more oil should do better.

I heard someone claimed tighter tolorense in the new engines need less oil, does this mean when the engine worn down and the tolorence get bigger, we need to put more oil!!!! Engine is not exactly a precision piece of equipment and manufacturer in the older days have absolutely no problem keeping the tolorence of today's engines with very little increase in cost.

I also heard someone claimed that excess oil in gas cause fouling plug and carbon buildup. Did they check the air fuel mixture before they made that claim? Too rich a mixture would definitely produce the same symptoms. As well as someone making mistake on calculation and put way too much oil. If someone put 10:1 mix then I can understand that will cause fouling and carbon.
I actually did an experiment. I put about 30:1 into my 4 cycle Troy Bilt trimmer TB475 which have separate oil and gas. I ran 2 tankful of 50:1 mix and only thing I notice is it gets oilly around the muffler area. The trimmer ran just the same, it has been 2 years since, and the trimmer ran just as good, no loss in power. I never change plug or do anything.

Please send in more comments, I think everyone can benefit from this.

If you think that 50:1 is not enough, how do you explain that some folks are mixing Opti-2 at 100:1? I don't use it, I stick with Stihl at 50:1 but I read others speaking highly of Opti-2. They even claim that Opti-2 can be mixed at 100:1 even in older engines calling for 16:1 or 32:1.

Here is a link that might be useful: Opti-2

That's a good one, I have not explaination. I look briefly on the link and it did said that, I have to do more research. 100:1!!!!
THanks for the info, people can learn about this. As I said lubrication has come a long way.

The needle, roller and ball bearings used now need very little oil compared to the plain bearings/bushings found in older equipment.

Two cycle oil does not fly through and out of the equipment as fast as gasoline does, now or then. When the fuel mixture enters the crankcase most of the gasoline vaporizes whereas the oil falls out of suspension and hangs around a while migrating through the engine.

If you crack open a 2 cycle it's surprising just how much oil is inside. This is not the best description but think of hosing the inside of a beer can with WD40 and letting it drain for 10 minutes.

Having said that I have settled on 40:1 in equipment that specifies 50:1. I think the EPA is kind of forcing manufacturers to go a little lean. High ratios are IMO probably OK if equipment is not run hard but I tend to run the blower wide open, thrash weeds down to the dirt with the trimmer and take more than an inch off the top with the hedge clippers. I figure oil is cheaper than my time or new equipment.

Hi Weed Cutter
I never heard about oil that disolve in gas will separate out upon violent shaking( I never heard of don't mean it is not true, could be my ignorance!!!) If oil only suspend in gas, I agree, but I believe oil do disolve in gas since they are both non-polar ( oil vs water which is polar). I don't believe one can separate out by methods like centrifusion( spinning fast where substance suspend in liquid will settle out toward outer edge). Did you read any articles about this? It will be very interesting to read.

The first engine I ever open is 8 years ago on one of the Weedeater cheap 2 cycle, it had all the ball bearing, the older ones don't have that?

I am not saying what you said is not true, I just don't know. Did you actually open the engine up and see thicker oil substance inside?
Thanks

"falls out of suspension" was an incorrect description on my part, it's not like churning butter. The gasoline vaporizes leaving behind the less volatle heavy oil. Just as if you poured some mix into a pan and left it to "dry", most of the gas goes into the atmosphere leaving behind most of the lubricant.

Some older 2 cycles do in fact have bushings. I suspect some new really cheap motors are manufactured with bushings now.

Yes I have seen oil films inside crankcases. Dip a piece of metal in 2 cycle mix, let it dry, barely any film remains. Your crankcase will have much, much more oil coating it than that.

To Weed Cutter
Thanks for the info.

To all that interested in oil mix issue, I was searching the web and found a link that test carbon deposit in different oil and mix. I am new at this and don't know the brand of oil. Take a look and give me feedback if you can. This is the only one that I found that actually did a control experiment on this issue. If anyone have other links, please share with the rest of us.

Thanks

http://www.geistware.com/rcmodeling/articles/oil_test/index.htm

The late great oil debate:
http://www.sea-doo.net/techarticles/oil/oil.htm

Thanks rmh3481 It is very informative. Anyone have anymore, please please sent us.

Everyone has their favorite brand for whatever reason. I think if you stick to buying a branded oil you will be fine (not some no name found at the dollar store). For hand held yard equipment I use oil designed for air cooled engines as opposed to "boat oil" with the TCW3 designation. I also use a fuel stabalizer as old gas seems to cause more harm than anything.

This is just what I do. I have read lots of posts from folks who seem to have luck with everything down to used oil from their car mixed somewhere between .1 and .001 but that's not for me. I think it's safe to experiment with fuel additives (in addition to the lube oil) if you want. Popular adds are Sta-bil, Seafoam and Marvel Mystery Oil and I think all 3 have some merit in some applications. Even if it's just to smell the spearmint in MMO (airplane folk love the stuff).

Most importantly just make sure to use some kind of oil at some ratio in the 2 strokers, straight gas will lead to a very short engine life. It's easy to get in a hurry and forget to make up the mix or just grab to wrong gas can.

Here's a site to ponder http://www.bobistheoilguy.com/
and good luck with it!

To Weed cutter: Thanks for the info. The web you gave just out of service for the moment, I'll try again tomorrow. About the stabilizer, how long can I store the gas if I add stabilizer. Do I add on top of the oil?

To Navada walrus: What is the update on the newer engines that make it better for emmision? Is the newer engines more subseptable to carbon bild up if excess oil is used? From the link I found that posted a few emails ago ( see above ) it seem to show more oil than about 32:1 give excess carbon buildup. Have you run any experiments on this?
Thanks

Stabalizer in addition to the oil, additives DO NOT replace the oil. Fuel storage 12 months depending on the dosage.
http://www.goldeagle.com/sta-bil/index.htm
Keep in mind Sta-bil itself has a limited shelf life.

To Weed Cutter: Thanks

Not so much carbon build up but cooked oil build up when using too much oil. Pull the muffler off a 2 stroke and look at the piston. If it has any burnt look to it the engine has probably had too much oil or the wrong kind of oil fed to it. This burnt look is fried oil stuck to the piston which makes the piston fit tighter which will lead to BIG trouble.

Thanks for everybody's contribution. Please look at the links that were suggested in the emails. I found it very educational. Didn't realize that oil is so complicated, high temp. oil, low temp. oil. This mean the link that I originally post is only test in one catagory: full speed. I am not sure the result apply to lawn equipments where we are not running at max speed and the engine might not be tune for max performence.

Do you think looking at the plug gives a good indication of whether there are excess buildups. ( taking to plugs off is a whole lot easier than muffler to look at the piston and muffler!!)

Anyone know what kind of oil is Echo, Shindaiwa makes and if I buy oil in Home Depot or Sears, are they good enough? Please advise.
Thanks

There is a book,that talks about 2 stroke engineering;it clearly says more oil gives more power,to a certain point..........also,castor bean oil gives the best protection,(against wear)but,it also builds gum,and carbon the fastest too.Synthetic oil burns cleanest,but doesn't quite give the same protection as castor oil.............But more oil gives more power.............that's why I always add a little extra, ,just to be safe.......just monitor your port to see what's happening..........Mark

Hi Jammer1
Can you give me the name of the book so I can check it out?
Thanks

1) Like yungman, I don't necessarily believe that I SHOULD run a 50:1 mix just because I CAN run 50:1.

2) Since the bottom-end oil supply comes only from the gas-oil mix, an oilier mix seems likely to result in a little more oil margin in the bottom end. This seems like a good thing to me.

3) Some of the mechanics commented that you can get deposits from overoiling, but if that is happening you can find evidence on the sparkplug, yes?

4) Newer engines that run very hot and lean would seem to me to be more able to oxidize oily deposits, yes?

5) Optimal oiling would presumably be affected too by ambient temperature and duty cycle - but the bottom line is, what is the safest general practice? I just use a little extra oil, e.g. use 5 gallons worth of oil in 4 gallons of gasoline.

6) Yungman, welcome to the US! We used to joke that Hong Kong was halfway to Chinea - now we might joke that California is halfway to the U.S.!

Hi Patentnonsense
I see you read my other page!! I like to go down the posting when I have time and soon I'll finish reading all of them.
I agree about a little more oil won't hurt. I always question when people talk about carbon built up. Wrong carb adjustment (too rich)will do the same. I think I'll put 32:1 and check the plug every 2 months.

BTW I am going to do an experiment using 30:1 ratio of Shindaiwa One with Sta-Bil in 91 Octane Chevron gas on both my Echo HC150 (21cc) and Shindaiwa EB3410 (34cc 4 cycle mix oil gas ). I am going to monitor the plugs. I check the plugs and found the Echo plug is a little wet with brown oil. I was using 25:1 before for 1 tankful. I guess it is a little excess. We'll see what happen to 30:1. I keep posting.

Be careful.............you can't really tell how much carbon is building up by looking at the plug!...........You must remove the exsaust;and inspect the port,and rings,thats the only real way to check for carbon building.................The name of the book is:TWO STROKE PERFORMANCE TUNING by A. GRAHAM BELL ....................please read it and get an eduction, and enjoy it..............it's full of hard facts.............

My two cents: Way back in the day two stroke mixtures were common engine oil mixed with gas. As for some of the comments I read, if your equipment is of recent age, mix as labled. Recent two stroke engines are running cats in the muffler. A heavy oil mixture will not benifit but harm your equipment. Be sure you use a good oil. A good oil will have a rating on the side of the bottle, the letters FC are what you should be looking for. I dont think you will find this at the big box stores.

This is one of the more interesting threads I've seen on this subject. On the one hand, the original poster's logic is correct. If the oils of the past were inferior, it's silly to believe that carbon buildup and plug fouling would be intolerable with modern synthetic oils at 20:1. On the other hand, Nevada Walrus makes a good point. In the old days, the more oil we added to the mix the richer we set the carburetor jetting to compensate (2-stroke racing motorcycles.) Many of today's engines don't allow carburetor adjustment, so at some point, more oil could theoretically cause a dangerously lean condition.

For what it's worth, I will now be using Mobil 2T, which I finally found at a Twin Cites Autozone store. And I always mix at 32:1. That's my compromise between the 16:1 I ran in the 70's and the 50:1 required by the EPA Nazis.

Castor bean oil(vegatable oil) give the most power;but it comes at a price;it absorbs moisture from the atmosphere,like brake fluid,and when it burns,it leaves a residue,which must be monitored and cleaned every so often,next is synthetic,wich doesn't give as much power,and not as much protection agianst wear,but burns very clean.............and least is mineral oil,wich offers the least protection,and can be fairly clean burning, but is only recommended for light use,such as a string trimmer,blower,etc..................a chainsaw could see light use depending how it was used;full throttle cutting 12 in dai. logs would not be considered light use.............Mark

I use Shindaiwa One at 32:1, I don't know what kind of oil is that. I am interested in Amsoil Saber and may be use it at 50:1, anyone have any experience on this?

I would go with what the manufacturer recomends,and add a pinch more "to be sure"..........50:1 is WAY too little,(In my book) IF you're supposed to run 32:1....you're almost halfing the oil you're using now.........synthetic or not I'd be leary about using LESS oil,regardless of oil maker's claim;unless it's a test engine,and you don't care if it seizes..........Mark

A number of years ago I had a homelite blower that called for 32:1 for conventional oil, but 50:1 for theirs or anybody elses semi-synth that met the proper spec (FC-JACO or something similar, I can't remember the exact reference)
So apparently even a manufacturer takes into account the type of oil.
My current echo's at 50:1 specify the modern semi-synth oil only.

I found this blog through a Google search of my question...
I was loaned a 25-30 year old Pioneer chain saw until i was able to get my own and was told to mix the fuel 30:1 (32:1). I mixed up 5 gallons and used about 3.5 before getting my new saw (Husky 570). I now have about 1.5 gal. of fuel mixed at 30:1 and my new saw is supposed to run 50:1. I contacted the retailer and of course was told to follow the manufacturers recommendation with no explanation as to what the ramifications would be of running the remaining 30:1 mix before switching to 50:1.

After reading all the replies, my take is I will not have any problems burning up the remaining fuel then mixing up a new batch at the recommended ratio and using this ratio for the life of the saw.

Any thoughts or concerns to my understanding?

It's only because emissions gets stricter . That's it!!!! Nothing else! Dirt bike manufacturers test their 2 strokes at 20-1 or 24-1. Huskavarna did some research and concluded a castor based oil was best for least wear . Echo (same engine) used to be 32-1 a few later 40-1 and a few years later 50-1 . Only because of emissions. Piss on what the manufacturer says . 28-32 to 1 . 32-1 is 4 oz oil to 1 gal gas

Have experimented with various oils on numerous small engine units for 40 yrs. Klotz R in Snowmobiles & Hot Saw @ 50:1 and Opti Tec in Old Chain Saws and Lawnboys @ 50:1. More Recently only Amsoil Sabre @ 50:1 on all 2 Strokes Units. Love the Smell of the Klotz Castor but that was back when tear downs were normal part of required carbon servicing practices. P.S. Only exception run Amsoil in my Yamaha Outboard @ 100:1 for over 10 yrs as recommended by the Manufacturer . Have never damaged a engine from oil starvation ! Oil is a Cheap Investment , buy the Best that you Can Afford !!!

I let the oil injection decide the ratio.

Back in the day Injection was well , less than perfect ! Todays systems much more precise and reliable . Still awaiting injection for my Hot Saws , perhaps Nitromethane Whadda Ya Think ?