converting 32:1 to 50:1

[andyd]

I mix an oily 32:1 I don't care if there are oils out there that can be stretched to a 100:1. At 32:1 I can run any oil in any OPE and know I'm not gassing it. My 40:1 spec Farmboss has been run from day 1 on it. It is 40 yrs old. It may be down a bit in power. Whoop dee doo! Smokes a little too, until it heats up. Doesn't faze me a bit. I have never had any carbon issues either. I may be on its 3rd plug, but the points and condenser are original as is clutch and sprocket

 

[lars11]

You can run anything you can buy in a shop at 50:1. I have not seen an engine spec:ing anything other than 50:1 or 100:1 since 1977 something when the super lemon, 2 cyl, 4 hp Johnsson outboard had a 4% sticker on it (25:1).
1980, 1990, 2000s Husqvarnas: 50:1
1980-1990s Yamaha, Mariner outboards: 100:1
All 1980 outboards: 50:1
Chinese, curve shaft trimmer: 50:1
That said, I run some OPE at ~80:1 with amsoil and Mobil.
And, you will not cause any problems with your 32:1, I would guess the worst that could happen is a dripping muffler, but unlikelly.

I have seen custom racing snowmobiles with scoring and pitted pistons at exhaust, but it does not seem to improve with more oil until you add enough to drop temps.

 

[mtgrs737]

I use 32 to 1 mix in all my 50 to 1 engines. No engine manufacturer would want you to lean out the oil mix in their engine, but the EPA has an eye on emissions and manufacturer's have to deal with them if they want to sell engines. More oil equals more power and less wear. Oil is the life blood of any engine I won't starve them for oil.

 

[BigDawg1]

Thanks to everyone who responded.
I can't believe I've had a separate gallon gas can for each 2 stroke engine (4 of them) with the particular manufacturers oil gas mixture requirement, all these years.
After reading everyone...it seems that whether the 2 stroke calls for 50:1, 40:1, 32:1...ETC, that 32:1 will be just fine. Sure will make mixing so much easier.

 

[Atesz792]

Be advised.. adding more oil will lean out the A/F ratio a bit. Probably not a problem, but still I thought I'd mention it.

 

[lars11]

Well, to some extent, I agree, 32:1 is ok by all means. But, it's unnecessary.
The engine -won't- last longer, you will use up more oil and there will potentially be some more smoke and maybe a liiitttle more cokeing. You won't be able to exeperience any more power in the run of the mill OPE either because of more oil.
So it's kind of a waste of good oil with no real upside. 50:1 is plenty of lube in a chainsaw or similar.
Lean conditions can kill you enginge though.

Originally Posted By: BigDawg1
Thanks to everyone who responded.
I can't believe I've had a separate gallon gas can for each 2 stroke engine (4 of them) with the particular manufacturers oil gas mixture requirement, all these years.
After reading everyone...it seems that whether the 2 stroke calls for 50:1, 40:1, 32:1...ETC, that 32:1 will be just fine. Sure will make mixing so much easier.

 

[Panzerman]

I own more two strokes than four strokes and I run 32:1 in all my yard equipment. My Craftsman weedeater is going on 22 years old. More smoke, no issues. Less oil is for emissions. If it don't smoke, it ain't a two stroke.

 

[DBMaster]

I think I am seeing some math errors.

To calculate a 32:1 mixture for a gallon of mix you need to divide by 33, not 32. (32 parts gas + 1 part oil = 33 total parts).

Using the same logic, to get 50:1 you divide by 51.

Thus, for a 32:1 gallon it's 3.9 ounces of oil. Using 4 ounces is obviously OK, though.

 

[Shrubitup]

Originally Posted By: DBMaster
I think I am seeing some math errors.

To calculate a 32:1 mixture for a gallon of mix you need to divide by 33, not 32. (32 parts gas + 1 part oil = 33 total parts).

Using the same logic, to get 50:1 you divide by 51.

Thus, for a 32:1 gallon it's 3.9 ounces of oil. Using 4 ounces is obviously OK, though.


It's a ratio. 32 parts more gasoline than oil. 128/32=4.

 

[Shrubitup]

Originally Posted By: Cujet


As a young man, I worked for a outboard race engine development team. One thing we tested was the affect of oil ratio on engine output. More oil makes more HP, all the way to 8 to 1. We also determined that 32 to 1 was the ratio that provided the highest wear protection, more oil did not help. BUT, Leaner ratio's resulted in more wear, with 100 to 1 showing significant piston skirt and ring wear.



Not insulting your age or wisdom but likely the best oil used back then did in fact cause accelerated wear at 100:1. Today's oil at this ratio in a low performance application likely don't wear as bad as what you saw.

 

[DBMaster]

Originally Posted By: Shrubitup
It's a ratio. 32 parts more gasoline than oil. 128/32=4.


Right, but 32 parts gasoline to 1 part oil. 33 total "parts."

4:1 does not mean the 1 is 1/4. It means the 1 is 1/5.

 

[DBMaster]

For all practical purposes it doesn't matter. Seems like the majority agree with the rest of you, but I guess, remembering my definition of ratios, they can be converted to fractions thusly.

1:32 really means 1/32. I can see it both ways, but I am going with the majority on this one.

 

[Mike72]

Well, to some extent, I agree, 32:1 is ok by all means. But, it's unnecessary.
The engine -won't- last longer, you will use up more oil and there will potentially be some more smoke and maybe a liiitttle more cokeing. You won't be able to exeperience any more power in the run of the mill OPE either because of more oil.
So it's kind of a waste of good oil with no real upside. 50:1 is plenty of lube in a chainsaw or similar.
Lean conditions can kill you enginge though.

Totally agree.

 

[dirtymudder]

So where do I stand with my 20/1 mixture on my 37 year old John Deere chain saws? I started to use a synthetic 50/1 mixture in it and now I'm wondering if I have done the right thing. Should I go back to the original mix or can I get away with the 32/1 mixture? Dino or synthetic at a 32/1 mix.

 

[Cujet]

Originally Posted By: Shrubitup
Originally Posted By: Cujet


As a young man, I worked for a outboard race engine development team. One thing we tested was the affect of oil ratio on engine output. More oil makes more HP, all the way to 8 to 1. We also determined that 32 to 1 was the ratio that provided the highest wear protection, more oil did not help. BUT, Leaner ratio's resulted in more wear, with 100 to 1 showing significant piston skirt and ring wear.



Not insulting your age or wisdom but likely the best oil used back then did in fact cause accelerated wear at 100:1. Today's oil at this ratio in a low performance application likely don't wear as bad as what you saw.


That's just the thing I'm trying to get people to understand. Two stroke oils are not significantly better at lubricating today! They are, however, significantly better at preventing deposits. (which does result in longer engine life, no more stuck rings and plugged exhaust ports)

Also, in engines with such a lean oil ratio, say 100 to 1, quite simply, the engine is at the threshold of inadequate lubrication under all conditions, regardless of oil type. Even the most pedestrian of two stroke engines produce excellent power and are highly loaded.

In fact, in recent test after test, the exact same results show up. I posted some results above. The magic super synthetic oils, run at lean ratio's result in accelerated wear, period. Regardless of what the oil claims.

Outboard engines do often operate at lean ratio's. They are water cooled, and designed to operate with minimal oil. Even so, at higher RPM and load, they do increase oil flow considerably. Hence the variable ratio oiling systems.

Your chainsaw, trimmer, lawnboy mower and other 2 cycle yard equipment are air cooled, high RPM, reasonably high performance engines. And in fact, often make considerably more HP per displacement than outboards.

Note: Variable ratio averages about 60:1, slightly leaner at idle and slightly richer at full throttle. The older pumps idled between 150:1 (prior to 1990) and engine failures were the result The pumps were changed to idle at 100:1 (1990-1992), then richened up to 50:1 as the engine load increased. Even so, many owners pulled the VRO pumps off due to rapid engine wear.

 

[Cujet]

Originally Posted By: dirtymudder
So where do I stand with my 20/1 mixture on my 37 year old John Deere chain saws? I started to use a synthetic 50/1 mixture in it and now I'm wondering if I have done the right thing. Should I go back to the original mix or can I get away with the 32/1 mixture? Dino or synthetic at a 32/1 mix.



Many of the older engines that specified such rich ratio's are constructed in a way that requires a lot of oil. I don't know if yours is this way.

Some two stroke engines do not have roller bearing connecting rods. (mostly older lawnboy's and low rpm engines) Also many older chainsaw engines simply used cast iron piston rings, often on chrome plated bores. (the opposite of what is common today)

These chrome bores were tough as nails as long as sufficient oil was used.

Also, many older 2 stroke engines simply specified 30W oil. The non detergent automotive oil at the "Rich" ratio. OR, if you used the factory provided oil, you could use a leaner ratio.

I don't know how your engine is constructed. But, I'd guess it's a chrome bore engine. 32 to 1 with a quality synthetic would likely be just fine.

 

[dirtymudder]

Thank you Cujet

 

[lars11]

Cujet knows his numbers, that's for sure. And idling at 150:1 is aggressive...
But, I also have lots of direct knowledge of Yamaha and Mariner(yamaha) smaller outboards under 90 hp. Many of which are labeled 100:1 mix and do not have any oil injection pumps.
I have two of those, one 6hp, one 30 hp, both from the late 80s. Run like champs, have lots of hours and no rebuilds. Friends use the 40 and 60 from that era and they seem to be touch as nails. Johsson Evinrude seem to be less tough but running with mix fuel they seem to last but are gas hogs.

All in all, heavily used outboards almost 30 yrs old do exceptionally well on 1% tcw3. Low specific output engines though.

Then I have read about the carting 16:1 tests and do know first hand about really HO snowmobile engines that kill exhaust sides at very few hours.

So to balance the discussion, I woill keep on runnning 50-100:1 on my low output garden equipmest and outboards.
If I get a ported chainsaw, a racing outboard or a aggressive snowmobile I will make sure I use at least 40-50:1 oil and the highest quality.

 

[andyd]

Whatever, I'm sure there are way more high tech lubes out there. I have a 38 yr old Stihl Farm Boss running at 32:1. My brother has burned out 3 saws in that time. He runs higher mix ratios. My experience dovetails with Cujet's. I have had no trouble with carbon fouling whatsoever.

 

[racin4ds]

Same here... those new lean ratios that started with Amsoils [censored] is a joke!

I will not run any 2 stroke at anything leaner than 50:1. Most everything I have including our race MX bikes with 2 strokes are ran at 40:1. More oil makes more power, results in better ring seal and in turn longer engine life! So what if you have a little carbon or spooge to clean ever so often? totally worth it to me!

Many also don't realize that with less oil you are richer on fuel and vice versa, so jetting and carb adjustments are absolutely necessary to run any mixture outside of what the carb was tuned for.