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Amsoil Dominator 50:1 oil vs. Manufacturers Recommendations

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Yep. Your the man...................

Edited by Mark6299

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Amsoil Dominator oil states to be used as injector oil or 50:1. What gives, 50:1 or manufacturers recommendations?????????

I am sure I could find more. I am interested in Amsoil since I have been using Amsoil at 40:1 in my YZ250 and Rm250 and 32:1 in my YZ125's. I have not seen any problems that I know of and the power valves are very clean after use at these ratios. I had a few friends tell me that they use Dominator at 50:1 and never had a problem. I wouldn’t mind having gas cans labeled with one or the other but having two set of cans could be a pain in the but. I had a dealer tell me that they recommend 32:1 for the 125's and 40:1 for the 250's, so that's what I have been doing. But they were not specific on which oils that refers to either. I know I will have to jet for whichever mixture I settle on nut I really want to know if 50:1 is the way to go. Amsoil did not distinguish the ratio based on the engine size. They talk about the demands of racing engines and such so one would figure that their 50:1 statement is good or it would be followed by a bunch of law suites, right?

I would run 32:1 or less.

But a lot of people run 50:1 and up with good results.

I believe Adam728 once posted that it takes less than 4 seconds for premix to run through the engine at WOT. But something like 3 minutes for it to run through at idle.

Therefore, for someone like me who's WOT all the time (high heat), I'll run 28:1-24:1 in a 250. But if you're lugging high gears around trails at half throttle (low heat), 40:1 would be fine.

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Personally I obeyed amsoil 50:1 ratio because my.bike was better for that. :lol: But I would run the ratio that your bike is jetted for. If one bike is jetted for 40:1 then I would run 40:1.

50:1 wouldn't hurt it all but I would just run what your jetted. It could.possibly make.life.easier in the long run.:)

Thanks man and.god bless

Alex

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I wish we had an answer to something. That being, when they market an oil, how do they go about it? Is it based on makign an engine last longer and have more power? Or is it based on telling a person the absolute minimum you can get by with?

For many years two strokes, of every kind, were 20:1. Then when emissions started becoming a big deal, suddenly it was ok to use less.

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I run Amsoil Dominator at 40:1 but I may end up switching to 32:1 or less this year. Im not getting slower, YET, and I think I may get a little better results with more oil. That means I need to rejet though after spending countless hours getting it perfect already:foul:.

I dont think that there is much to be had as long as your bike is jetted properly for whatever ratio you chose. I just want to give "more premix" a shot for 2 reasons, one being that I ride my bike at WOT pretty much all the time on the track and my oil volume in the crank is low when measured, and 2 I want to give the "more oil = more power" rumor a test. I figure it cant hurt anything.

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It seems to me that there's probably a 'saturation' point for each engine where any more oil isn't doing you any good and another ratio where a lot more starts clogging things up and effecting the combustion process.

Unfortunately there isn't a formula or any serious scientific research being cited to determine what the minimum safe and max-effective oil ratios are for each engine.

To further complicate things, each oil is not created equal. Just like the data on suspension fluid (search the forum) that shows how much difference there is between any two manufacturers oils even at a given specification like 5wt or 10wt.

Two stroke oils don't really even specify a viscosity, film strength, specific gravity, etc. without getting into data sheets or contacting the manufacturers. They just adhere to the ratings like TCW-3, etc which are spec'd for boats, chainsaws and lawn equipment.

ftball90, I run 32:1 in both my YZ250s, I can't say I've done a back to back test with 40:1, but I feel more comfortable with the extra bit of oil and I don't see any problems with clogging up the PV, spooge, etc.

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Maxima sez to use less oil as your displacement increases (and assumed RPMs sustained) AND based on the type of riding expected. For example if you ride trails on a 250cc two stroke they say somewhere between 40-60:1 using their oil. If it's MX racing then down to 24:1.

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And just to throw in a little more to confuse the topic.

Most manufacturers of chain saws, weed whackers, leaf blowers, and other really small 2 stroke engines suggest running premix at 50:1 ratio. I know that those engines are typically run wide open and sometimes for a pretty good length of time. Chainsaws are typically run wide open and under a heavy load.

So, are the oils formulated for those engines better than our typical oils? I know that there are precious few carb adjustments on those engines (really just an idle and an airscrew).

What would happen to our engines if we ran those oils at the 50:1 ratio?

I have often wondered, but never tried it for fear of causing some serious damage.

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It seems to me that there's probably a 'saturation' point for each engine where any more oil isn't doing you any good and another ratio where a lot more starts clogging things up and effecting the combustion process.

A few years back I got to sit and take to an engineer and ubber performance engine builder. He had some theories on the effects of mix ratio on combustion, but it's so much "richer" than what we run that it doesn't matter much, in my opinion. His thoughts were basically don't worry about it, unless you plan to run under 20:1 with castor, or in the low 20's with synthetic (idea being that longer molecule chains in the synthetics can interfere with combustion at a leaner mix). His theories were based on what he'd seen in dyno testing.

Unfortunately there isn't a formula or any serious scientific research being cited to determine what the minimum safe and max-effective oil ratios are for each engine.

I think it would be near impossible because of the various conditions our bikes see in terms of rpm, load, and throttle position. Testing at steady state could be done, but once you throw in that Joe is faster than Bob, or that one guy rides high rpm, small throttle opening, while another rides down below power peak with the throttle hammered, etc etc, the itterations become near infinite.

To further complicate things, each oil is not created equal. Just like the data on suspension fluid (search the forum) that shows how much difference there is between any two manufacturers oils even at a given specification like 5wt or 10wt.

Two stroke oils don't really even specify a viscosity, film strength, specific gravity, etc. without getting into data sheets or contacting the manufacturers. They just adhere to the ratings like TCW-3, etc which are spec'd for boats, chainsaws and lawn equipment.

For most oils that info is fairly available. I'll try and remember (maybe someone could PM me Sunday night?) and post up an Excel file I made with data on about 140 different 2 stroke oils. Some of the new ISO ratings correlate well with what a dirt bike needs. C and D level oils are some good stuff. Unfortunately not many companies have picked up this rating system yet.

And just to throw in a little more to confuse the topic.

Most manufacturers of chain saws, weed whackers, leaf blowers, and other really small 2 stroke engines suggest running premix at 50:1 ratio. I know that those engines are typically run wide open and sometimes for a pretty good length of time. Chainsaws are typically run wide open and under a heavy load.

So, are the oils formulated for those engines better than our typical oils? I know that there are precious few carb adjustments on those engines (really just an idle and an airscrew).

What would happen to our engines if we ran those oils at the 50:1 ratio?

I have often wondered, but never tried it for fear of causing some serious damage.

Chainsaw spec'd oil is usually pretty decent, it has to survive decently high specific power output and high rpm (many Husqvarna saws are spec'd to run 13-14K). Trimmer and blower oils usually are pretty low grade. You are talking 28-40 cc engines that make 1 hp at 7000 rpm.

One big reason for the leaner recommended mixes is emissions. Lawn and garden equipment must met them, and the more oil you run the higher the hydrocarbon output becomes. That, and catalytic convertors don't like it. Most all 2 stroke trimmers/blowers have a small catalytic element in the muffler now (looks like a matchbook sized steel wool piece). It has to last a specified number of hours (50 for homeowner stuff, 300 for pro models). EPA isn't too happy if it gets burnt out/clogged up and emissions goes sky high before the products end of life. Chainsaws have gone to stratified charge to avoid needing cats (yet). Much costlier setup than buying a $1-2 element though.

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Oh yea, and Maxima oils did hte study on oil migration and made mix recomendations from that based on engine size, use, etc. Like stated previously, a small engine wound hard needs more oil than a big one lugged around. That's why it's crazy to believe an oil manufacturer that says "XX:1 is best for everything." A top level SuperMini needs a lot more oil in the mix than Joe trail rider that never gets the powervalve to open.

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I run 40:1 in all my yzs 125,250,85 and ktm 50 and they all run great, very little spooge. It's all in the jetting

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We talked for a bit and shot the sh&^ for a while. In summary, Amsoil Dominator has been thou rally tested and the results show that the 50:1 recommended ratio would supply the best performance and protection. He said that I could mix at the engine manufactures ratio if I wanted but it will not help anything. He also said many racers use Dominator and mix it at 50:1 with best performance and results. As a side note, I know some of you will say that the racers don't care if the engine life suffers because they rebuild their engines on a regular basis. I think if that were the case then the racers mechanics would determine that on their own, or at least in private, with an Amsoil engineer and agree that they will gain performance at the expense of the engine. However, I certainly doubt that Amsoil would print false information on a bottle oil just for let's say fun. That would lead to many lawsuits I think. He said I could safely have one set of gas cans labeled 50:1 instead of several at different mixes. If you are like me, call them yourself with your concerns. I will go with what I heard from the horses mouth and not from he said she said and such. Just thought I would share what I found out.

Rally tested?

How does less oil equal more power?

Everything I've ever seen tested or been part of testing generally shows more oil = more power, to a point (and that point is FAR more oil than a 50:1 ratio). Better ring seal, less friction between the piston skirts and cylinder walls, etc. The downside can be extra drag on the lower end bearings (believe it or not, too much oil can cause bearing skidding, excessive windage, etc).

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I don't know about Rally testing. I am not into that. We talked about dirtbikes, not Rally cars. I didn't even know that they had two strokes in them. :lol: My bad, damn spell check.:) "thoroughly tested" good catch.

Look, I don't know about this stuff, that's why I called and asked them. When you ask a question in a forum setting and most of the replies are very close to one another, you tend to believe that there is some truth or sense to the answers. But when you get so many widely differing opinions than one could shake a stick at, then you had better go to the source. And we could speculate all we want and he said she said or so and so said this and that, till we are all blue in the face. Or, like I said, we could ask the source. That's what I did. Perhaps you should give them a call and share your vast knowledge of lubrication with them. Perhaps they missed something and you could enlighten them. Or they could explain to you what they did and how they did the tests. Then you could post back here better explaining what they said because I surely don’t understand it like many people here. Don’t kill the messenger. All I did was call them and ask the question about my concern about their 50:1 mixing information they printed on thousands if not millions of Amsoil Dominator Racing Oil labels. I am sure I am not the only one who was wondering the same thing.

Not trying to kill the messanger, but your posts never said who the message came from, just "We talked for a bit and shot the sh&^ for a while." I take it from this last post that you called Amsoil directly, right?

I take info lightly without knowing the source. There's plenty of threads on here showing that REALLY poor information can often be found from "experts at dealers, etc. How many threads do we have saying "This is the last year for Yamaha 2 strokes, my dealer told me so!" Along with crap from 14 year olds that will argue with industry experts because of something their buddies uncle told them about powerbands. I didn't know if you were talking to the dealer, your friend's weird uncle, an Amsoil rep, an Amsoil enigneer, etc.

Edited by adam728

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I want to give the "more oil = more power" rumor a test.

its already been proven 30 years ago by gordon jennings and graham bell with castor oil. never seen the same test with dominator type oil. with all the clean burn junk amsoil has in it, i would doubt the "more oil" theory would be true but im no oil expert. if you doubled the oil content from 50:1 to 25:1 your doubling the additives, solvents and what ever other garbage they put in there. ya i dont see the more oil theory being true for the modern age synthetics

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Oh yea, and Maxima oils did hte study on oil migration and made mix recomendations from that based on engine size, use, etc. Like stated previously, a small engine wound hard needs more oil than a big one lugged around. That's why it's crazy to believe an oil manufacturer that says "XX:1 is best for everything." A top level SuperMini needs a lot more oil in the mix than Joe trail rider that never gets the powervalve to open.
I think it would be near impossible because of the various conditions our bikes see in terms of rpm, load, and throttle position. Testing at steady state could be done, but once you throw in that Joe is faster than Bob, or that one guy rides high rpm, small throttle opening, while another rides down below power peak with the throttle hammered, etc etc, the itterations become near infinite.

I agree with both statements, there are just too many factors to make a blanket statement of which ratio is best all the time.

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Well, actually, I did say who I talked to. I guess you didn't see the header. No biggy, I miss those too sometimes myself.

Well, now you had to go and make me look dumb in front of myself. :lol:

I'll stick by what I said. 1 mix ratio is not best for every bike, every rider, every condition. Amsoil is very good at marking, and 3 of the 4 reps I've met were very good at repeating what was written in their brochures, and nothing more.

A shifter kart needs more oil than a CR500. A 125 putting around with a beginner on top of it doesn't need the same amount of oil as a 125 being wrung by Stewart.

There's PLENTY of information out there about these things. Don't just take the word of the company giving you a sales pitch. Research.

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I will mix at whatever I want, and so can you. We are just trying to show you that there's plenty of info out there that directly clashes with Amsoil's claims. A. Graham Bell's 2 stroke book talks a good bit about using different ratios for different bikes, conditions, and even riders. Mentions that faster riders generally need to run more oil because the are revving the bike higher, on the gas longer, etc. Eric Gorr even has some literature out there saying that the more you rev, the more oil you need. Amsoil can't magically beat oil migration.

A little about me

  • I wrenched at a dealer thru college
  • Now am a Mechanical Engineer
  • Work for "the world's largest manufacturer of carburetors"
  • I spent 5 of my years here at engine manufacturers all over the world, working mainly with 2 strokes, and with some engine engineers that have been designing these things longer than I've been alive.

Your profile says you are an engineer. With a little reading it should be very easy to understand why 1 ratio doesn't fit all applications.

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Or just go ahead and mix your oil at what ever you want. But then don't use your cell phone while pumping gas either. We all heard that one too. Wait, the myth busters already did that one, didn't they???

I thought it was a static electric discharge that caused the boom? Either way, did you hear about Mythbusters missing the water barrel with a cannon this past week? Good read.

FYI, the local Amsoil tech rep told my finacee to change her oil once a year. But seeing your earlier post, you might not find that crazy. I asked him if he had done any tests on year old oil for film strength, viscosity, iron, anything? Nope, he heard this info. from another rep.

Go pick up your old fluids book. It's a great read when you don't have to worry about tests.

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