Oil ratio

don wallace · Posted: Thu Feb 26, 2004 8:03 am Post subject:

Disclaimer, We are Rookies, 4 hole can, kt 100, starting our second season. Locally everyone uses Motul. Our engine builder recommends 7 oz for breakin, 6 oz thereafter. Seemed to smoke a lot with 7, 6 is good. Now in the shop for second topend, all looks good. Everytime I get comfortable with an aspect of the kart, this forum shows me logically that I am 100% wrong. So here goes. My son does not tune the carb yet, so we run a little rich. Lots of greasy exhaust, but only 1 out 10 karts is faster on the straight. I want him to start playing with it, but fear he will lean it out too much and stick it. If I up the ratio to 8oz would it protect against a too lean mix? (just in case). And might we gain a little performance in the bargain? I have learned to pull the head and decarbon regularly, as we only pass tech by a whisker, so alittle build up doesn't bother me. We have neither the expertise, nor the money, to run "on the edge". Looking for good consistant performance with minimum risk.

Pete Muller · Posted: Thu Feb 26, 2004 8:22 am Post subject:

Matt Gaskins · Posted: Thu Feb 26, 2004 9:47 am Post subject:

Pete,

I have several questions on some points you made..

1st: "Needless to say, the jet needs to be "opened up" on the carb as you add more and more oil (so that you're still getting about the same amount of *gasoline*, though more "fuel mixture"). "

Oil and gas are premixed, so opening up the jet will only increase the amount of oil/ fuel mixture, not just gasoline.... Correct?

2nd: "Conversely, more oil will not prevent seizure."

I know nothing can prevent seizures if a engine is run to hot or if it is over revved. But, the more oil, the less chance there should be.. ??

tracy blumenstein · Joined: 03 Feb 2004 Posts: 5

has anyone else tried power plus ,we run 8oz. and cam2 and we have had no problems and it still make good power

Pete Muller · Posted: Thu Feb 26, 2004 11:50 pm Post subject:

Chris Richter · Posted: Fri Feb 27, 2004 2:40 pm Post subject:

Pete,

Have you done any testing to see how the oil mix ratio has an effect on the fuel meter?

Our roadrace committee plans to test for different ratios before the Grand Nationals (maybe even this weekend).

Chris Richter, PKA tech.

c w owen · Joined: 30 Dec 2003 Posts: 35

Pete Muller · Posted: Tue Mar 02, 2004 10:18 am Post subject:

Once again; oil has very little to do with causing or preventing seizures.

The real test of an oil is to pull the engine down and look at the rollers out of the big-end rod bearing under a microscope.

PM

George Miskovski · Posted: Tue Mar 02, 2004 11:02 pm Post subject:

Keith Young · Posted: Mon Oct 23, 2006 7:31 pm Post subject:

For years the Porsche air cooled crowd has debated the effacacy of traditional (dino) vs. synthetic. There have been numerous debates concerning themal viscosity, break down characteristics, adhesion and lubricity. The conclusion, mostly Laughing

has been that synthetics are far and away superior to dino. But, since we are doing oil changes so often, it really doesn't matter becasue the modern oils are great too!

I can understand much of this same argument for kart engines and oils. The synthetics are proably better? But, the traditional oils, given that we burn them almost immediately, are certainly as suitable. So the pudding should be, when similar engines are layed side by side and disassemble, is there any measurable difference between the synthetic fed engine and the dino fed engine?

Steve O'Hara · Posted: Mon Oct 23, 2006 9:36 pm Post subject:

Keith,

Castor is not "dino" as you call petroleum based oils. The properties of castor oil are much different than synthetics or petro based oil. Castor is unique among oils as it will flow toward heat rather than away from heat and that is why it is so effective in two cycle motors. I have done no research on modern synthetics to compare them with castor so I can't say much about them but I have extensive experience with castor and would not run any other oil in a racing two stroke engine no matter what type of engine or fuel I'm using. Serious racers will never run an engine long enough for meaningful carbon build up to occur without having the top end apart to inspect the ring, clips, bearings, wrist pin etc. If that is an issue then you aren't racing hard enough to need castor Smile

Never use less than 8oz. per gallon and use 10oz if you can without fouling plugs.
Pete and I have been good friends for decades and we did much of the testing on this stuff jointly and I can back up everything he has said here. One area of clarification... I think Pete would agree with the statement that more oil will not guarantee against a stick but it can help avoid one if you are right on the edge.
Rule of thumb.... run a lot of oil no matter what type you choose to run and you'll have better results. One thing I can say for sure.... reducing the amount of oil has never made any kart engine I raced run faster... they just wore out quicker.
Steve O'Hara

Larry Andrews · Posted: Mon Oct 23, 2006 11:47 pm Post subject:

I agree about using more oil - 8oz/gal of castor (Maxima 927) really did seem to keep the wear down although practically everyone seemed to think I was loony.

One problem that I never did really figure out was how to manage plug fouling with the engine hot and *off*. Seemed like more oil in the mix would cause puddling in the bottom end of the CR125 stock moto mill, which would then mist up from heat and foul the plug when the kart was parked.

I developed a habit of pulling the plug and shooting it with brake cleaner before going out - but that seems kinda silly as noone else seemed to be doing it. Once the plug was pulled, massive amounts of oil mist would just spew out the plug hole...took quite a while for it to stop.

Anybody got any ideas? Is this to be expected?

Steve O'Hara · Posted: Tue Oct 24, 2006 6:02 pm Post subject:

Larry,

That's a new one... I've never seen anything like you described with any kind of oil in any amount. Any chance you have a minor water leak and the "mist" you see coming out the plug hole is water/coolant vapor?
Steve O'Hara