2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Premix potential problem?

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Old Sep 22, 2005 | 06:49 PM
  #1  
ProjectRESuperG's Avatar
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Talking Premix potential problem?

Ok, I may be thinking about this a little too much/hard, but I was just wondering, when you premix, and let's say you add 1 oz premix to 1 gallon of gas, even if you're dead on accurate, and do not over add the premix, wouldn't you end up with an increasing amount of premix?

Not clear enough?

Ok. Say you just started premixing, you go to the gas station to fill up, say 13 gallons, and you add 13 oz of premix, everything good. Ratio correct, everything a-ok. Next time you go fill up, same thing, 13 gallons to 13 oz. However, consider this: whatever's left in your gas tank is ALREADY premixed. While this doesn't sound like much, eventually, wouldn't whatever remaining gas in your gas tank get increasingly more saturated with premix?

Maybe not a real problem with people who always fill up when the low fuel light comes on, but what about the people that like to keep the tank topped up?

I know, I must be bored out of my freaking mind for thinking about this, truth is, I am, haha.

Just thinking out loud, any thoughts anyone?
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Old Sep 22, 2005 | 06:55 PM
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From: Vernon, BC
no.



if the ratio you put in is always 100:1 or 150:1.. it will stay at the ratio... MATH!!! WOO HOOO

if you have it half full of premix, and you fill it the rest of the way, that means you would put in HALF the amount of oil you would if you were filling the whole tank.

weird how things tend to amke sense like that
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Old Sep 22, 2005 | 10:08 PM
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Yup, as long as you are always putting in a constant mixture of 100:1 it will remain 100:1 in the tank.

The only time this is false is when you first start pre-mixing which is why it's always recommended to go ~150:1 on the first tank to make up for the extra fuel in the equation.
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Old Sep 22, 2005 | 10:10 PM
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are you bored or drunk?
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Old Sep 22, 2005 | 10:10 PM
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Hmm...funny how math works like that
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Old Sep 22, 2005 | 10:54 PM
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When to put the premix in it disipates into the gasoline. It mixes. the two do not seperate or anything. It's like coolaid...once you put the little package of stuff in there, it's there to stay.
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Old Sep 23, 2005 | 12:13 AM
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Here's the scary thing.

You always hear " 1 OZ of 2-stroke oil to every 1 gal of fuel " to achieve a ratio of 126/128: 1. I don't know how that ever got started but it shouldn't at all be the "rule" Different manufactures require different amounts of oil to achieve a certain ratio What's good for one manufacture doesn't at all apply to another. Some oils are thicker & more concentrated. Thus, using the standard 126/128:1 (1 OZ to 1 gal) ratio way of measuring it will cause of overly or under rich mixture, depending on the oil used.

Now to freak at the matter a little more. Different manufactures suggest using a different ratio when using their oils. Say you normally mix @ 50:1 but many companies will suggest that you lean it out to 100-1 with their oil because it's that much better and doesn't require as much to achieve the same protection.

The point is, there is no set amount of OZ's to add to 1 gal of gas. The proper mix all depends on the oil used.
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Old Sep 23, 2005 | 12:33 AM
  #8  
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From: Under The Hood In FL
Originally Posted by ProjectRESuperG
Ok. Say you just started premixing, you go to the gas station to fill up, say 13 gallons, and you add 13 oz of premix, everything good. Ratio correct, everything a-ok. Next time you go fill up, same thing, 13 gallons to 13 oz. However, consider this: whatever's left in your gas tank is ALREADY premixed. While this doesn't sound like much, eventually, wouldn't whatever remaining gas in your gas tank get increasingly more saturated with premix?
No. You started off with the correct amount to begin with. You remixed with the correct amount, the outcome is still the proper amount. Your fuel pump isn't separating the oil from the gas. It's being consumed @ X ratio and leaves behind the same ratio.

There are other factors. 1 Cheap oil doesn't stay suspended as well and 2, if the car sits for a long time, the gas will evaporate, leaving behind the oil. In this sense, it will effect the ratio.

Variables aside, you won't create a leaner or richer mix, if you add an equal amount each time. It won't change. No matter how many times you do it.
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Old Sep 23, 2005 | 01:34 AM
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Originally Posted by ProjectRESuperG
Ok, I may be thinking about this a little too much/hard...
Actually I don't think you were thinking hard enough...
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Old Sep 23, 2005 | 04:40 AM
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If you are using TCW III pre-mix, you have nothing to worry about. It will meet the certification for standardized ratios.

Are you trying to find something to worry about, or just couldn't think of anything else to start a thread?
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Old Sep 23, 2005 | 06:15 AM
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1) Look at the bottle - most brands will tell you consult your (whatever is using the pre-mix insert here) for proper ratios. Sure, viscosity isn't the same, but I think the major brands all shoot for very similar ratios when engineering their chemicals. Ratios do not vary much when looking from brand to brand.

2) Unless you drop the ratios down to under 50:1, you can't tell the difference. If anything, I would worry about NOT ENOUGH pre-mix. If you work out the numbers from what Mazda uses for the OMP, I think it comes out to something like 300:1 to 400:1 range. Since we're a lot "richer" than that, I wouldn't worry about not enough pre-mix.


-Ted
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Old Sep 23, 2005 | 05:04 PM
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pic

Idemitsu sugests to use half ounce of premix fer gallon. Now what is confusing is if we can not use synthetic oil in our cars why is it ok to put synthetic premix. Idemitsu is synthetic. I have not been able to find the premixes that were recomende by everyone so I'm using castrol synthetic premix. Here is a pic.
Attached Thumbnails Premix potential problem?-premix.jpg  
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Old Sep 23, 2005 | 07:40 PM
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Originally Posted by redlineracer
Now what is confusing is if we can not use synthetic oil in our cars why is it ok to put synthetic premix.
Well, for starters, premix oil is designed to burn cleanly, leaving a lubricating film behind. Synthetic or not, if it's designed to burn cleanly, it'll burn cleanly.

-=Russ=-
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Old Sep 23, 2005 | 08:08 PM
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Originally Posted by redlineracer
Idemitsu sugests to use half ounce of premix fer gallon. Now what is confusing is if we can not use synthetic oil in our cars why is it ok to put synthetic premix. Idemitsu is synthetic. I have not been able to find the premixes that were recomende by everyone so I'm using castrol synthetic premix. Here is a pic.
BUT! If you pre-mix and have your OMP system blocked off you can run synthetic. It's one of the reasons I switched over on my FC (although I haven't run synthetic yet).

The problem with synthetic motor oils is that many of them leave ash deposits and are not designed for combustion. The synthetic two-cycles are formulated not to ash and are therefor ok.

I've never tried synthetic two-cycle, I've just been getting the Walmart brand TCW-3 certified stuff in the big jugs and it smells alot less and the engine is running just as smooth as it was with the more expensive Castrol TCW-3 I was using.
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Old Sep 23, 2005 | 08:15 PM
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can you put too much oil? could this cause any starting/running problems?
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Old Sep 23, 2005 | 09:20 PM
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i have been running about 80:1 for about 8-10 months. no problems except i think it is clogging my primary injectors
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Old Sep 23, 2005 | 09:56 PM
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Originally Posted by WannaSeeMyWankel
can you put too much oil? could this cause any starting/running problems?
Not that I've seen. I'm sure you could get it to the point that you have nothing but sludge in your tank but if you're stupid enough to put that much in.... well, just don't over-do it.

I've ran it on the heavy side when I first switched over off the OMP just to be sure and because I decided the best way to find out what it likes is to start heavy and thin it out until it stopped smelling like a chainsaw and ran nicely and found that 100:1 seems to work well with mine.
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Old Sep 23, 2005 | 11:19 PM
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What if you ran the omp off of a seperate tank (not crankcase) and used ahigh quality 2-cycle oil?
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Old Sep 23, 2005 | 11:21 PM
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I meant high quality synthetic 2-cycle.
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Old Sep 23, 2005 | 11:51 PM
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Works fine. Rotary Aviation sells the parts you need to do the conversion.
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Old Sep 23, 2005 | 11:52 PM
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The exhaust tends to smoke when you run around 50:1 ratios or "richer".
You gotta be kinda crazy to run lower ratios???
I mean dumping a whole quart into a full tank would barely reach this 50:1 ratio...
Are you planning on dumping a whole gallon of this stuff into your tank?


-Ted
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Old Sep 24, 2005 | 01:20 AM
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what is the walmart brand called and how much?
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