Opti-2 claims "single mix", yet ratio varies depending on package size. WHY???

[Scrap Farm]

Until recently, I thought Opti-2 had a recommended mix of 100:1. I'm now aware that the 1.8 oz pouches for a single gallon of fuel give a ratio of about 71:1. At the opposite extreme, they sell a 1.06 gallon jug of oil they say mixes with 110 gallons of fuel: That's about 104:1. In between these extremes, other package sizes give various ratios in the 80s and 90s.

Does anyone know why this is? Does the concentration of the ingredients vary depending on the size of container you buy???

Sorry if this has already been covered. I tried searching the forum, but the hundreds of results were impossible to sift through.

 

[bwalker]

Why would you run less oil than the OEM says to run? Do you think a rinky dink company like Opti or Amsoil is on to something so special that their oils can be ran at these ridiculous ratios?
I just don't understand the obsession with running as little oil as possible

 

[MacAttack]

I was waiting for someone else to say it... but 100:1 is just insane, I'd run motor oil at 16:1 before I'd run any oil at 100:1.
Addressing the question, I highly doubt they'd have different blends of oil, they probably are just gambling that anything from 70 to 100:1 will work.

 

[dwaugh]

I think part of is rounding of numbers when converting from Standard to Metric units. The 1.06 gallon is also labeled 4 liters...

 

[slowcar281]

I emailed them and asked the same thing a couple of years ago. It’s to accommodate international mixing, ( liters vs gallons )

I ran it for an entire summer at 71:1 or 1.8 oz per gallon and had no issues, even in my lawnmowers that call for a 32:1 ratio.

Ironically they don’t recommend mixing it any thicker than 1.8 oz per gallon for any machine regardless of the ratio the equipment called for originally

 

[OM617YOTA]

100:1 is ridiculous. Do you drain 3.5 quarts of oil out of your car engine and go drive around too? What about donate a gallon of blood and then go do cardio?

No clue why people try and see how close they can get to running their equipment without oil.

 

[bwalker]

I emailed them and asked the same thing a couple of years ago. It’s to accommodate international mixing, ( liters vs gallons )

I ran it for an entire summer at 71:1 or 1.8 oz per gallon and had no issues, even in my lawnmowers that call for a 32:1 ratio.

Ironically they don’t recommend mixing it any thicker than 1.8 oz per gallon for any machine regardless of the ratio the equipment called for originally

If your 32:1 speed mower is a vintage Lawnboy or a newer Duraforce you probably drastically shortened it's life span.
Why do you think it's advantageous to use some off brand oil at such a high ratio?

 

[slowcar281]

If your 32:1 speed mower is a vintage Lawnboy or a newer Duraforce you probably drastically shortened it's life span.
Why do you think it's advantageous to use some off brand oil at such a high ratio?

Yes they are all Duraforce mowers. Models 22261, 22260, and a 10323. These are homeowner used.

I ran the 22261 at the 71:1 ratio for an entire summer mowing using it once a week religiously to mow 3/4 an acre. They spec about 3200 max rpm but I run it just shy of 3600. They cut a lot better that way IMO

A few months ago I split the case and replaced the seals on the 22261 simply due to age and curiosity of how the engine looked internally. The was nothing wrong with the mower otherwise.

I couldn’t see any abnormal wear and there was hardly any carbon. The engine still had 118 psi of compression.

I’ve ran a lot of different of oils at different ratios just to see what would happen. I’m too chicken to run it at 100:1 but some people claim to with no problems.

I’ve now settled on 50:1 with any major brand ope oil. The Rtek engine is nearly identical to the Duraforce except its piston ported vs the Duraforce’s reed valve. The Rtek recommends a 50:1 ratio in the snowblower and runs upwards of 4200 rpm’s in the high output snow commander snow thrower.

For some reason the Lawnboy still specs a 32:1 ratio and a much lower rpm spec. I’ve read it’s because of blade speed.

 

[ZeroJunk]

I have been running a 10323 since back in the eighties. Use whatever 50 to 1 I use in chainsaws.
The deck is going to finally fall apart. Not sure I can patch it much more.

Engine is fine.

 

[slowcar281]

I have been running a 10323 since back in the eighties. Use whatever 50 to 1 I use in chainsaws.
The deck is going to finally fall apart. Not sure I can patch it much more.

Engine is fine.

It’s probably a different model than a 10323. That mower came out in 1998, when Lawnboy switched from the F series to the Duraforce.

 

[cscltd]

I remember when toro/lawnboy came out with the duraforce/rtek engine.
They said they wanted to run the mower at 50:1, but I think it was showing lubricating issues in California testing at 50:1, but no problem in northern states for mower and cooler temp for snowblower version. So to be safe the mower was labeled 32:1 and snow blower 50:1. Mind you they were testing with their lawnboy Ashless oil, (which I don’t think was the greatest?) may have been ok with a better oil?

 

[slowcar281]

I remember when toro/lawnboy came out with the duraforce/rtek engine.
They said they wanted to run the mower at 50:1, but I think it was showing lubricating issues in California testing at 50:1, but no problem in northern states for mower and cooler temp for snowblower version. So to be safe the mower was labeled 32:1 and snow blower 50:1. Mind you they were testing with their lawnboy Ashless oil, (which I don’t think was the greatest?) may have been ok with a better oil?

I’ve always wondered why the difference in ratio. I always thought it might have been obvious that a mower would be used in hot weather and a snow blower in cold weather, so the extra lubrication would have been needed in the summer.

They were also jetted very lean, with an incorrectly sized throttle plate as well. A lot of them surged terribly out of the box when new

 

[ZeroJunk]

It’s probably a different model than a 10323. That mower came out in 1998, when Lawnboy switched from the F series to the Duraforce.

Wrong date maybe. It is definitely a 10323. I have a couple of F's . May be mixed up.

 

[cscltd]

Not to mention that the crankend bearing and housing on grass side would wobble a 1/4” if was used for heavy mulching after a year in landscaping

 

[cscltd]

Wrong date maybe. It is definitely a 10323. I have a couple of F's . May be mixed up.

Wasn’t there that “z” engine which a bastardized f engine

 

[slowcar281]

“V “ series. It’s very similar to an F I believe

 

[AnthemBassMan]

Wasn’t there that “z” engine which a bastardized f engine

You might be thinking of the V Series engines from the early 90s after Toro took over. It may be coincidental, but the one time I bought Opti oil was when I had my 10201 with the V Series engine. Opti was an 80:1 mix then. I ran my 10201 for a couple weeks with that mix and bye-bye connecting rod. But that one time was the only time I bought Opti. I’ll stick with my Amsoil Saber mixed 40:1. If I run out of Saber then I will get Echo Red Armor. I run that mix in every 2 stroke I own from my 1975 5024 Bricktop with the D-433 engine, and my 1978 5277 with the F-100 engine through my new Stihl MS261C.

L8R,
Matt

 

[bwalker]

Yes they are all Duraforce mowers. Models 22261, 22260, and a 10323. These are homeowner used.

I ran the 22261 at the 71:1 ratio for an entire summer mowing using it once a week religiously to mow 3/4 an acre. They spec about 3200 max rpm but I run it just shy of 3600. They cut a lot better that way IMO

A few months ago I split the case and replaced the seals on the 22261 simply due to age and curiosity of how the engine looked internally. The was nothing wrong with the mower otherwise.

I couldn’t see any abnormal wear and there was hardly any carbon. The engine still had 118 psi of compression.

I’ve ran a lot of different of oils at different ratios just to see what would happen. I’m too chicken to run it at 100:1 but some people claim to with no problems.

I’ve now settled on 50:1 with any major brand ope oil. The Rtek engine is nearly identical to the Duraforce except its piston ported vs the Duraforce’s reed valve. The Rtek recommends a 50:1 ratio in the snowblower and runs upwards of 4200 rpm’s in the high output snow commander snow thrower.

For some reason the Lawnboy still specs a 32:1 ratio and a much lower rpm spec. I’ve read it’s because of blade speed.

The Rtek is ran in cooler temps for starters but it's not a robust engine either. I have ran all my RTEK's at 32:1.
I have had several duraforce motors scatter with a piston collection to prove it. The common failure mode in them is for the big end rod to break from big end bearing wear. The RTek does the same thing as I just had one fail last winter.
You are not doing you machine any favors what so ever running those ridiculous ratios.
Attached is two DF pistons and 1 Rtek piston on the right. All three had big end rod bearing failures, although the one on the left sucked one of the metal reeds through the engine which probably did the rod no favors. The rod is aluminum and has a hokey shell over roller bearing set up that just isn't a good design.

 

[bwalker]

I remember when toro/lawnboy came out with the duraforce/rtek engine.
They said they wanted to run the mower at 50:1, but I think it was showing lubricating issues in California testing at 50:1, but no problem in northern states for mower and cooler temp for snowblower version. So to be safe the mower was labeled 32:1 and snow blower 50:1. Mind you they were testing with their lawnboy Ashless oil, (which I don’t think was the greatest?) may have been ok with a better oil?

You really need to run an ashless oil in them. The are governed to a constant RPM and engines that are run like this, wether they be air planes, boats or mowers all need ashless oils.

 

[bwalker]

I’ve always wondered why the difference in ratio. I always thought it might have been obvious that a mower would be used in hot weather and a snow blower in cold weather, so the extra lubrication would have been needed in the summer.

They were also jetted very lean, with an incorrectly sized throttle plate as well. A lot of them surged terribly out of the box when new

RTEK's do the same thing. I drill the jet out on them to the next size larger.