Maintenance & Technical > KX500 Original

Oil thoughts and questions - anyone heard of this?

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dmg:
Anyone using Castor oil based premix any more?

I ran into someone at Chapparal today that gave me an ear full about oils. Here is what he said:

Castor Oil comes from plants, and this is what everyone used to use. The growing and harvesting of Castor oil slowed way down when they found out how to make synthetic oils that worked almost as good. Because the Castor oil plant is toxic, and required harvesting, most oils are now synthetic.

He said that the Castor oil is a superior lubricator. He said the oil sticks to everything in the engine better, and does not wash off with gas as easily. This prolongs bearing and top end life.

The other topic he brought up was about transmission oil. He said there are a number of grades of oil, and there are specific ones for motor cycle transmissions. SAE stands for standard automotive engineering. This is not good for wet clutches because they have abrasion inhibitors in them, and this can cause the clutch to slip. He highly recommended running an oil that had a MA -### on it. It was at the bottom of the label on the back. The racing oils didn't have it. The non racing oil of the same brand did.

He was not a store worker, and not a sales guy. He just offered the info as I was standing next to him by the oils.

Any comments or thoughts?

KXcam22:
dmg,
I think he is pretty close.  In the old days castor was superior to mineral oil as a lubricant. It's only downside was that it would separate out of the gas and tended to gum up rings.  Those are not an issue with new castors who have an addititves to prevent that.  However, when it comes to lubrication synthetics kick the crap out of castor oil.  They do not smell as nice. Nothing does.  Many synthetics run best at 100:1 while you won't find a castor that recommends much leaner than 40:1.  You have to keep in mind that oil brand is a personal choice - everyone has their favorites.  I'm a Belray guy and have used nothing but for more than 30 years -superior results. Again, personality and a bit of superstition involved.  Like many people, I have a selection of different 2-strokes at home (bikes, boats, weedwaker chainsaw etc) so to make life easy I run my 60:1 bike premix in all of them. There are many great oils out there. 

With respect to transmission oils the guy is also correct BUT its like running nitrogen in your car tires. There are some benefits for the cost, but air has worked just fine since tires were invented. Same for oil. The Jaso MA certification means it is for high friction use (ie clutch etc).  Sure it is better but how much better is debatable and regular motor oil has worked for me in my transmission since my first mini-bike.  The one area where I make sure I use a true motorcycle oil is in 4-strokes that share the engine and trans oil. These oils have something like 5X the anit-wear additives and have specific long-chain polymers that are meant to pad gears in a gearbox.  A lot also depends on the type of engine.  I don't feel bad running automotive oil in my sons XR100 but I use nothing but the best synthetic I can get in my 450.  Different stress levels on the engine mean using different classes of oil.  Hope I haven't confused you more.  For the KX500, I would suggest sticking with your castor oil until you feel like trying something else (or get tired of the spooge)  and using regular 10W30 car oil or ATF in the transmission.  Sorry for the sermon. Cam.

Friar-Tuck:
  We can divide 2 cycle oils into 3 basic categories; petroleum based, castor oil based, and synthetics. While a few oil companies market petroleum based 2 cycle oils, they are primarily for lawn mowers, small outboard boat engines, and other low-performance applications.
    Petroleum as a lubricant ? is a pretty good rust preventative. A quick look at a drop of petroleum under a high-powered microscope is enough to convince you not to put this stuff into a high-performance  engine.
    Even the highest quality petroleum oil contains a surprising amount of particulate material: little bits of gritty stuff that looks positively scary under a microscope.  Petroleum oil doesn?t burn all that well and leaves a lot of debris behind when it does.

Castor-based oils have been a favorite of high-performance tuners for more than a hundred years. In it?s most elemental form, it is the oil squeezed from Castor Beans (and its not significantly different from the vile tasting stuff  grandma used to cure constipation).   
 Today?s castor-based 2 cycle oils bring some extraordinary qualities to the table.
 Castor has by nature great film strength. That means it resists pressure between 2 surfaces without being squeezed out and allowing the surfaces to touch. This is especially important in a highly stressed 2 cycle engine.
  The point of contact pressures on connecting rod bearings in particular are almost unimaginable at high RPMs.
  Another of castor oil?s  qualities is what oil experts refer to as ?wetting ability.? Simply put, wetting is the ability of the oil to spread itself out to coat the entire surface of whatever it touches.
   (It?s the same effect that adding detergent to the water in the kitchen sink has, aids in breaking surface tension.  Just like the stuff for cooling systems.
  Some of you may be old enough to remember when oil for your car was advertised as ?Detergent? oil. Those oils had wetting agents in the addative package  to help the oil coat the inner surfaces of the engine for better protection from corrosion & break loose/down particulates.
    But alas, the report on castor oil as a 2 cycle lubricant isn?t all good.
    Some of the gums and other components that Mother Nature put in the castor bean don?t burn all that well and they can leave a gooey mess behind that can make piston rings stick in their grooves. And the parts that do burn can leave behind a significant amount of carbon on the piston crown and the inside of the head.  Most of today?s castor-based 2 cycle oils as described as being ?de-gummed or low ash? but that is really a relative term. They have less gum and leave less carbon than their non-de-gummed cousins, but it is still something the user needs to be aware of. One other negative you need to be aware of is that castor-based oils have a disturbing tendency to ?fall out" (separate) of solution in gasoline when they get below 50 degrees or so.   This is not an ?every time? thing and that may have to do with the various additives in addition to the castor oil in the oil bottle your using. But it is a significant consideration if your riding might include some cold days or nights.
  Snowmobile guys use specially formulated stuff for low temps, and there are blends for "injection" too.   
 
So let?s see, castor oil ?wets? very well, but it leaves a lot of carbon and gummy residue, . So why is it so popular with tuners and engine builders?
    Two words: IT WORKS. 

          But what about the 3rd category of 2 cycle oils; the synthetics.
 As the name implies, these are "cooked up" in the laboratory looking for compounds that offer excellent "lubricity", surface-wetting properties, and, in the case of 2 cycle oils, clean burning.
   These oils were originally based primarily on a family or organic chemicals called esters. By comparison to castor oils, these "new-generation" oils offered a number of advantages. Their solubility in gasoline and methanol made them easy to mix and to keep mixed. Unlike castor they did not deteriorate over time, either mixed with fuel or still in the bottle on the shelf. They also left fewer deposits behind when they burned. They are an excellent choice.
     The energy crisis, with its lines at gas stations and newfound interest in fuel economy, focused a lot of attention on synthetic lubricant research. Sunoco and Mobil Oil in particular made tremendous strides in developing oils that ,
   A: didn?t require petroleum as a raw material, and
   B: provided significant friction reduction to increase fuel economy. Their research spawned thousands of new companies developing and marketing a vast variety of lubricants and/or additives. These products greatly expanded the old ester-based synthetic lubricant sphere.
       By and large these new oils have a lot to offer. They have outstanding lubrication properties, they are highly soluble in both gasoline and methanol, and that solubility is not temperature sensitive, and they are exceptionally clean burning. That does not mean that every synthetic product can do everything it promises. I?ve heard some fairly outrageous claims and tried a few products, but there is also plenty of ?snake oil? out there.
  If you stick with one of the top brand-name synthetic oils, you?ll likely be very happy with the performance.

The cleaner burning properties of these synthetics mean that the ritual cleaning of pistons and rings that was  part of the castor- based world not all that long ago has been reduced significantly.
          (I'm not sure if you all would like the "White Paper" stuff or not )
     I'll try to post up on tranny fluid tomorrow...it's past my bedtime & I'm Pooped!

Tuck\o/

KXcam22:
Tuck,
 Good write-up.  I have to agree with the low carbon aspect of synthetics.  I got 14 years out of my K5 top end (est 400hrs -but singletrack so not as engine stresssing as others).  I had NO carbon -None, and much less than expected wear. It works. Looking forward to the 2nd part Tuck. Cam.

3Razors:
I have seen repeated dyno tests of bikes jetted correctly with castor based oil such as Maxima 927 run at 20-32:1 make 3-4hp more than the same bike with correct jetting for 50-100:1 with synthetic 2 stroke oils.

Also KX500 is not a exactly a high-rpm engine.  They are usually hanging their tonque out around 8k rpms so you can squeek by with running 50:1 or leaner.  But if you had a 125 or 250cc motor on a roadrace or drag they turn considerable higher rpms in the 12K range so more protection/oil is needed.  There are alot of variables and no oil is perfect for everything.  Another note is I would avoid synthetic oils if you live in wet/damp climates as they dont provide the rust protection of castor on the internals of a motor.

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