125-200cc 40:1? 32:1? what ratio are you running?

[HUNhusky]

recently purchased a 2006 cr125, previous owner said he ran 36:1. just looking around to see what kind of oil and what kind of spark plugs you guys are running in your bikes?

 

[2premo]

50:1 synthetic
new bikes show 60:1
when i was sponsoring a bike we were 100:1 synthetic, no wear issues

 

[Cookies]

most people use too much oil, i.e. 32:1. Remember the more oil you use, the less gasoline will be present, thus leaning out the mixture, sure everything is lubed well, but the engine is still lean. With todays Synthetic oils, 50:1 is not uncommon.

 

[HUNhusky]

what brand oil are you guys using?

 

[justintendo]

i use klotz super techniplate castor/syn blend @ 40:1. hardly any smoke, no spooge. my 88 250 has run it almost its whole life. still running great on stock piston.

 

[PowerKord]

40:1 with Maxima K2 here.

 

[justintendo]

your engine will also not be "lean" running 32:1....jet accordingly.

 

[Big Timmy]

Take also into consideration excessive amounts of oil can actually cause the engine to work harder by increasing friction and parasitic drag alone.

To much 2 stroke oil added to the gasoline can also have an effect on reducing the specific octane rating of the gasoline used as well by simple mathematical dilution.

Gotta love the smell of any castor based oil out on the trails as well. Castor based oils once introduced into the internals of any fresh 2 stroke engine, once run at operating temperature will leave a beneficial micro thin layer of protection unlike anything else. That protective layer will remain on the surface nearly for ever unless removed with strong chemical cleaners during teardown. Even gasoline will hardly remove this film or layer.

Even the lower content of Castor oil by percentage in 2 stroke Synthetic blends that are now available will leave an oil film on all the metal surfaces that do not have direct wear against other components. Like the bottom sides of the sleeve or bore, the rod, flywheels, etc. This will protect the internals from oxidation or corrosion during long periods of storage.

Full synthetic 2 Stroke oils just don't have the ability to do this as well in my opinion.

 

[HUNhusky]

what kind of spark plugs you guys running? ive read these husky's are pretty specific in what they need, a spark plug with a resistor ( i think its called ) big timmy.what kind of oil do you use? brand wise

 

[dirt-dude]

Maxima K2 @44:1 NGK BR8ES

 

[troy deck]

Amsoil dominator @50:1 NGK BR8ES

 

[justintendo]

b8es

 

[PowerKord]

B8ES

 

[ajaxauto]

OMG Here we go again but since you asked My 2006 CR 125 which is still on the original bore since new and had won the following

2 National # 1 plates in the AMA National Hare and hounds 1 in the 125 expert class and 1 on the over 50 open expert class
Won a few Dist 37 Desert races
Ran as high as 6th overall finish at a Desert race out of 300 plus entered
Preran King of the Moto 3 years in a row
Has a ton of miles by 3 different expert riders ect ect

So here is what has worked for me Stock jetting from the factory never change from sea level to 8,000 feet
BR9EG Uriduim Plug
mixed lucas semi synthetic oil about 35 to 1
110 leaded race gas
This has worked for me like I said still on the original bore My 2008 CR 125 which is now a 165 gets the same stuff NEVER lost or hurt a motor in either bike
I talked to Walt today as my son wants to make it a 165 and do KOM next year Poor old bike keeps ticking

PS lower end is also all original except one crank kit

 

[Huskynoobee]

Just remember the golden rule. You bought the bike running and jetted for 36:1. Start there and see how it runs, what the plug looks like etc.

 

[Big Timmy]

Been running old school "Blendzall" green label #460 for 40+ years in my vintage Maico's. I buy it by the case.
Have tried a few bottles of the "Klotz BeNol" also but don't look for it or see it very often. Since I get the Blendzall just shipped to my door.

If I store pre-mixed fuel over the winter here which I normally won't do, I'll keep a bottle of the #490 booster additive that keeps the castor from separating if it sits for a long time. Only a few ounces is needed to do this. Shaking the bike around good before riding probably does the same thing. I am one of those guys who leans the bike way over to dump fuel from the carbs overflow tubes all over the floor of my shop or ground when the bike is cold before kicking it anyway. Saves my bad knees a bit and it lights right up.

They now have a #465 Gold label that has the booster already in it but I just mix the two (#460-#490) myself. Its what I've used for years and don't have any reason to change.

I've ran full synthetics before just don't care for them. Except maybe in my 3 chainsaws. Husqvarna, Stihl and my cheapy loaner Poulan, the one and only one that ever gets loaned out.

 

[jmetteer]

This is an article I remember reading back in the day, it has some interesting points.

I personally use Amsoil interceptor at 32:1 on my bikes.

Later,

Pre-mix 101

OK, looks like it's time for a little pre-mix 101. I don't usually get into ratio discussions, because mix ratios are like religions to most people, and they tend to be closed-minded on the subject, but I'll put in my $.02 here anyway.

There is a prevailing myth that less oil is better, and that the oil in the fuel is what lubricates the engine. Both are wrong.

*less oil is better* People think that if they have a plug fouling problem or a lot of spooge, they need to run less oil. Wrong! Both problems are caused by rich jetting, and have nothing to do with the mix ratio.

*the oil in the fuel is what lubricates the engine* The engine is lubricated by the residual oil that builds up in the crankcase. All the oil in the fuel does is replenish this oil.

The best way to determine if you are running enough oil is to check the level of the residual oil in the crankcase. If the ratio you run leaves enough residual oil in the crankcase to cover about 1/8" of the bottom of the crank wheels, then you are fine. If you don't have that much residual oil in your crankcase when you pull the top-end off, you aren't running enough oil for your riding style and conditions.

With that said, to have that amount of residual oil in the crankcase at 50:1 (a ratio made popular by magazines and oil bottles), you can't be riding very hard, or your bike is jetted richer than necessary simply to deliver enough oil. I arrived at 26:1 for my bike with my riding style because that is the amount that gives me the proper amount of residual build-up. Small-bore engines require greater oil concentrations than larger engines to achieve the proper amount of residual build-up, because they rev higher and have higher intake velocities. Along the same lines, someone that pushes the engine harder, and keeps the revs higher, also needs to use higher oil concentrations to achieve the proper residual build-up.

To understand why the residual oil is so important, you have to understand what happens to the oil in your fuel when it goes into the engine. While the oil is still suspended in the liquid gasoline, it can not lubricate anything. It has about as much lubricity at that point as straight gasoline. When the gasoline enters the engine, it evaporates, dropping the oil out of suspension. Now that the oil is free, it can lubricate the engine, but it must get to the parts to lubricate them. The way it gets to the bearings and onto the cylinder is by being thrown around as a mist by the spinning crankshaft, and the droplets are distributed by the air currents moving through the engine. Ever wonder why there are two small holes in the transfer port area of the crankcase, right over the main bearings? These are to allow some of the oil droplets being flung around inside the engine to drip down into the main bearing area.

Some of the oil eventually makes it into the combustion chamber, where it is either burned, or passes out the exhaust. If the combustion chamber temps are too low, such as in an engine that is jetted too rich, the oil doesn't burn completely. Instead, some of it hardens into deposits in the combustion chamber, on the piston, and on the power valve assembly. The rest becomes the dreaded "spooge". The key to all of this working in harmony is to jet the bike lean enough to achieve a high enough combustion chamber temperature to burn the oil, but also still be able to supply enough oil to protect the engine. If you use enough oil, you can jet the bike at it's optimum without starving the engine of oil, and have excellent power, with minimal deposits and spooge. At 50:1, you simply can't jet very lean without risking a seized engine due to oil starvation, unless you're just putt-putting around on trails without putting the engine under much load.

With the high oil concentrations that I use, I tend to get far more life from my cranks and rings than most of my friends that run leaner oil ratios. The high oil content also produces better ring sealing, so more of the combustion pressure is retained.

One small point. No one ever broke an engine by using too much oil.


_________________________________________________________________________________________________

Pre-mix ratios and power production

I have run Dyno tests on this subject. We used a Dynojet dynamometer, and used a fresh, broken in top-end for each test. We used specially calibrated jets to ensure the fuel flow was identical with each different ratio, and warmed the engine at 3000 rpm for 3 minutes before each run. Our tests were performed in the rpm range of 2500 to 9000 rpm, with the power peak of our test bike (a modifed '86 YZ 250, mine) occuring at 8750 rpm. We tested at 76 degrees F, at 65% relative humidity. We started at 10:1, and went to 100:1. Our results showed that a two-stroke engine makes its best power at 18:1. Any more oil than that, and the engine ran poorly, because we didn't have any jets rich enough to compensate for that much oil in the fuel, and the burn-characteristics of the fuel with that much oil tended to be poor. The power loss from 18:1 to 32:1 was approximately 2 percent. The loss from 18:1 to 50:1 was nearly 9 percent. On a modern 250, that can be as much as 4 horsepower. The loss from 18:1 to 100:1 was nearly 18 percent. The reason for the difference in output is simple. More oil provides a better seal between the ring and the cylinder wall.

Now, I realize that 18:1 is impractical unless you ride your engine all-out, keeping it pinned at all times. But running reasonable ratios no less than 32:1 will produce more power, and give your engine better protection, thus making it perform better for longer.

 

[2premo]

lets do some simple math, parts of gas to parts of oil
36:1 = 2.77777%
40:1 = 2.5%
50:1 = 2%
unless you are tuned to the n'th degree on a flat area such as a competition course and i don't mean enduro stuff
realistically unless you are tuning as lean as you dare for the last 2% of power available then less than 1% won't change much
spooge usually comes from poor ignition as in not burning clean, gross over jetting, bad spark plug, low compression, timing off
you probably get where i am going with this
if you don't feel comfortable with 50:1 don't lose too much sleep
don't worry about rejecting when you change the ratio either there is no jet that will compensate 1% available from anyone
if you plan to run a lot of elevation differences typically i jet for the lower elevation
FYI most of my riding is 3000' of elevation difference
the quality of the gas you run is more important, i run Chevron premium as it is the most consistent, the manufacturers of cars use it for emission testing
a lot of members run fuel that is for competition with no ethanol (a big deal) i am at high altitude so don't have the issues that would affect me there 5000-8500'
enjoy the ride!

 

[HUNhusky]

2premo i see what your saying, the minute differences between mixes isn't going to even be noticeable by me, as long as the bike runs fine theres not much to scratch my head at. as far as the gasoline used ( i live in the USA ) what octane do you guys use? pump gas the highest we can get is 97, but I'm sure i can find some race gas around somewhere.. with a 36:1 ratio, what kind octane gas are most of you running? thanks for all the help guys

 

[2premo]

This is an article I remember reading back in the day, it has some interesting points.

I personally use Amsoil interceptor at 32:1 on my bikes.

Later,

interesting read
i sponsored a friend of mines son on a Suzuki 60 in the day, he won almost every event he entered, so we built him a modified 60 that ran higher RPM, again won almost every event, we were teched after pretty much every race for a year and had the top end off regular no wear, 100:1
he was the US mini champ for quite a number of years, i quit sponsoring him when he got a factory ride with Kawasaki
Eric of Eric's Pasadena who won an ISDE gold said there was no reason to run extra oil, he did his dyne work at 150:1 with no visible wear
after long discussions he got me to go 50:1 and said i was chicken, the new as in KTM and Husqvarna recommend 60:1 right in the owners manual
all my buds that ride these have had no problems all these years