2-STROKE SETUP?????

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2/20/2008 6:38 PM
Edited Date/Time: 4/16/2016 5:55 PM

MY 2 STROKE HAS BEEN SPITTING OUT A LOAD OF OIL CHECK OUT THE PIC BELOW LOOK AT THE PIPE AND SWINGARM ANYWAY I WAS TALKING TO THIS GUY ON DIRTRIDER.COM AND HERES WHAT WE HAVE TO SAY...IF YOU ARE HAVING THE SAME PROBLEM OR WANT TO ADD FEEL FREE TO ASK AND POST YOUR ADVICE.




skipkh: Every day the issue of premix ratio comes up - either directly or indirecly. I'm typing this post up and I'm going to put it in my signature line so that I don't get cranky beating this horse any more!

Why do so many of the veteran riders around here promote 32:1?

Here's why.

1. Factories determine things such as jetting, slide cutaway, and spark plug temperature based on a specific air/fuel ratio. If you put less oil in the gas (ie; 40:1, 50:1, 100:1) then the ratio is off and the mixture becomes richer. Cylinder temps go down, plugs start fouling, oil comes out of the pipes, etc..

2. An engine requires a specific amount of lubrication - the lower end bearings, rod bearings, wrist pin, and cylinder wall (just to name a few) have to rely solely on the tiny bit of oil you put in the gas. Less oil = more friction which = faster wear on these parts.

3. The oil in the fuel helps to seal the rings during compression. Too little oil, and the compression sufferes, leading to a loss of power.

4. Oil manufacturers add a detergent package to oil, and in most cases is is based on a 32:1 mix ratio. Any less or more oil, and the detergent package is no longer in spec - causing the oil to perform differently than it was designed to.

Many engineers spent considerable time and resources developing a proper premix ratio - if you follow it, you and your bike will be much happier!

There - it's off my chest. Whew! Sorry if I offended anyone...







ME: can someone please help me...i am currently running 31:1 on my stock setup(with a clean filter every time i ride and a new spark plug every other riding time) and a load of oil still spits out of my pipe and makes a big greasy mess all over the bike...(i have to use a full bottle of engine degreaser each time i ride). I figured that the leaner(put less oil) i go, less oil would come out...so now im running on 40:1 but this guy says "If you put less oil in the gas........oil comes out of the pipe." ????????????? WHAT SHOULD I DO?????






skipkh: SuzukiRM,

I know how confusing this can be.. oil's coming out of the pipe, so you figure there's too much in the gas and decide to put less oil in (higher premix ratio), but no luck. It would only make sense that the less oil you put in the gas, the less comes out of the pipe, right?
I wish it were that easy..
What determines how much oil will come out of the pipe is how hot the conbustion temperature gets. You need a certain amount of heat to burn off the oil. When you run 32:1 premix, you basically have 97% gas and 3% oil. When you run 40:1 premix, you have 97.5 gas and 2.5% oil. So, in 40:1 you have more gas in each charge than in 32:1 - with me so far? OK - now more gas means richer mixture... the mixture is determined by a ratio of gas to air, and oil isn't factored into the equasion. 97.5% gas is more than 97% gas, right? Ok - so now we know that 40:1 ratio is actually richer than 32:1 (Air fuel ratio). The richer the mixture, the cooler the combustion temperature. Believe it or not - gas acts as a coolant in the cylinder! So - by going to less oil (40:1 or higher) then you're actually making the mixture richer, which in turn makes the combustion temperature lower, which means there is not enough heat to burn off the oil.
So what should you do? It sounds to me like you have a jetting problem. Go back to 32:1. Make sure you are running the proper temp plug for your bike, then lean out your jetting a little until the bike runs well, and doesn't drool oil excessively out the pipe. It could definitely be the jetting. We need to know 2 things - what jetting does it have in it now, and what's the altitude where you live/ride. Let me know and I'll get you on target for the proper jetting. Also - double check the plug.. i believe it should be a BR8EG, but your owners manual will say for sure - if it's a different number that's in the bike, like BR9, then you might be running a plug that's too cold..








ME: the plug is an R6918B-8...According to the manual...




skipkh: Oh - that sucks... it's a fine plug, don't get me wrong, but darned expensive. There's a bit of debate over this one, as - technically, an NGK BR8EG should work fine, however there have been cases of faulure when using the standard (cheaper) NGK plug - the one your manual specs has some structural reinforcement to prevent the failure. Now the million dollar question - are you currently running the same plug as specified in your manual? Or something else...
Also, the 05 RM was notoriously fat in on the needle jetting - it should be on the 2nd clip from the top - not the 3rd that the manual specifies. You can also tweal the air screw a little - I like to adjust it until the bike idles well for a couple minutes and doesn't belch white smoke.



ME: thanx ill give it a shot





HOPE THIS HELPED!!!!!!




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Just saying.

2/20/2008 8:04 PM

When rings wear on a 2-stroke, or the bike was not broke in correctly, they will not seat properly.

In either case, the gas/oil mixture (ratio) does not burn completely.

Thus, spewing unburnt oils through it's least path of restriction.

There are cleaner oils to mix...Maxima 927, is one of the better (IMO)
But my guess is that it was not properly broke in, and the rings are not seated. Meaning you got it to hot to soon.

125s are tempermental...you have to be presise when breaking in a 125, for it to function at it's best.

good luck

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2/20/2008 8:42 PM

Mike Bierman wrote:

When rings wear on a 2-stroke, or the bike was not broke in correctly, they will not seat properly.

In either case, the gas/oil mixture (ratio) does not burn completely.

Thus, spewing unburnt oils through it's least path of restriction.

There are cleaner oils to mix...Maxima 927, is one of the better (IMO)
But my guess is that it was not properly broke in, and the rings are not seated. Meaning you got it to hot to soon.

125s are tempermental...you have to be presise when breaking in a 125, for it to function at it's best.

good luck

thanx for the oil recomendation...i am currently running AMS OIL DOMINATOR. Ya im aware of engine seisure and how important it is to break in the bike properly...when i first got it back in december of 06 i took it out to some easy trails thoughrly warmed up the bike, and spent about 10hours with a hlaf open throtle and 5 hours with about 3/4 open throtle...Im just trying to fiddle with the carb and try to get the right jetting ......although i dont thik its improper break in i strongly believe its the jetting because even during my first ride oil was dripping just as bad as now...

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Just saying.

2/20/2008 10:02 PM

Mike Bierman wrote:

When rings wear on a 2-stroke, or the bike was not broke in correctly, they will not seat properly.

In either case, the gas/oil mixture (ratio) does not burn completely.

Thus, spewing unburnt oils through it's least path of restriction.

There are cleaner oils to mix...Maxima 927, is one of the better (IMO)
But my guess is that it was not properly broke in, and the rings are not seated. Meaning you got it to hot to soon.

125s are tempermental...you have to be presise when breaking in a 125, for it to function at it's best.

good luck

927 Smells really nice, but I would hardly call it clean. When I ran it I had to power wheel off the burnt carbon off the power valve. When I ran HP2 I wiped it off with a rag.

The reality of it is, jetting needs to be monitored. This is one of the downsides of two strokes. It effects four strokes as well but not as much. Temperature in the air, moisture, poorly mixed gas. The spooge on the swingarm can be fixed but you will always have to attend to jetting. I would agree with the rings if the spark plug is correct, but it looks WAY too rich to me rings or not.

Every two stroke I have had, 32:1 No problems, I still would get spooge if I didnt jet correctly. Overall I wouldnt worry about it too much. Clean more. It's the nature of the beast.

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