Post by: benji.dojo.3 on September 09, 2012, 03:29:19 AM
Just wondering what the best fuel/mixture ratio is.
Currently running at 32:1 , some guys suggest running it at 40:1, Using MOTUL Oil also.
All suggestions would be much appreciated.
Thanks
Post by: cnrcpla on September 09, 2012, 04:01:55 AM
But 32:1 is usually pretty safe and good to run.
Post by: benji.dojo.3 on September 09, 2012, 04:39:19 AM
running 32:1 at the moment bike runs a dream, just a thin bit of smoke behind the bike thats barley visible to the eye, but heard 40:1 gets more power but more chance of blowing the motor up?
Post by: Jeram on September 09, 2012, 09:49:29 AM
Yeah I got bigger jets, when I put the fmf fatty pipe and powercore 2 silencer, rejetted.
running 32:1 at the moment bike runs a dream, just a thin bit of smoke behind the bike thats barley visible to the eye, but heard 40:1 gets more power but more chance of blowing the motor up?
less premix will absolutely positively NOT make more power, who ever told you that is full of shit
The opposite has been proven, more oil on the bore and rings = a better ring seal = more hp
I run 20:1 but it gets expensive, stick to 32:1 if your motor is stock-ish
Post by: benji.dojo.3 on September 09, 2012, 10:02:20 AM
Yeah I got bigger jets, when I put the fmf fatty pipe and powercore 2 silencer, rejetted.
running 32:1 at the moment bike runs a dream, just a thin bit of smoke behind the bike thats barley visible to the eye, but heard 40:1 gets more power but more chance of blowing the motor up?
less premix will absolutely positively NOT make more power, who ever told you that is full of shit
The opposite has been proven, more oil on the bore and rings = a better ring seal = more hp
I run 20:1 but it gets expensive, stick to 32:1 if your motor is stock-ish
All i have done is change the pipe to a FMF fatty , powercore 2 silencer, put bigger jets & put the mototassinari vforce3 in.
Post by: beaner on September 09, 2012, 02:05:40 PM
The opposite has been proven, more oil on the bore and rings = a better ring seal = more hp
I run 20:1 but it gets expensive, stick to 32:1 if your motor is stock-ish
I understand the theory, but I have yet to see any relevant proof of this. Everybody seems to refer to tests that were done almost 40 years ago when materials and oil were a lot different than they are today. Do you have any info?
That aside, it's impossible to make a recommendation without any information, like bike, riding style and application.
Post by: arnego2 on September 09, 2012, 05:34:33 PM
less premix will absolutely positively NOT make more power, who ever told you that is full of shit
The opposite has been proven, more oil on the bore and rings = a better ring seal = more hp
I run 20:1 but it gets expensive, stick to 32:1 if your motor is stock-ish
+1 I run it 25:1 as I have to slow down once in a while and 20:1 at low rpm is not really the best.
Post by: citabjockey on September 09, 2012, 06:27:37 PM
That is the ONLY full synthetic I have used and since have stopped (because its tough to measure accurately, makes a mess when working with it, and is bloody expensive and is a 30+ year old oil design). I lately have been using the Lucas semi-synthetic at 32:1. Before that I had history with several mineral based 2T oils at 32:1 and never had any problems. The Lucas stuff seems to maintain that tradition. It mixes easy, very little smoke or spooge, no fouling plugs and the engine seems quite happy with it. And its pretty cheap and easily available at lots of auto parts stores around here.
Post by: Jeram on September 10, 2012, 01:48:01 AM
The opposite has been proven, more oil on the bore and rings = a better ring seal = more hp
I run 20:1 but it gets expensive, stick to 32:1 if your motor is stock-ish
I understand the theory, but I have yet to see any relevant proof of this. Everybody seems to refer to tests that were done almost 40 years ago when materials and oil were a lot different than they are today. Do you have any info?
That aside, it's impossible to make a recommendation without any information, like bike, riding style and application.
bernouli's principals is not effected by time, they are much older than 40 years. and just like newtons laws of motion they are constant and will never change.
you put some viscous fluid between the piston, rings and bore therefore constricting this 'orifice' by some degree which reduces the total volume flow possible for a given pressure differential.
As a consequence a slightly higher pressure in the combustion chamber is observed.
Makes perfect sense to me.
but by far the biggest gain is superior engine protection.
Post by: beaner on September 10, 2012, 02:51:41 PM
I'm wondering why manufacturers like Rotax and KTM (not to mention the trials guys at 80-1 and 100-1) are recommending 50-1 and 60-1 now. I suspect that with modern materials and modern oils, that 32-1 is overkill for anything but riders at the top level, or 2 strokes that are truly run on the ragged edge. Something that most of us will never do.
Post by: arnego2 on September 10, 2012, 03:04:25 PM
Post by: benji.dojo.3 on September 11, 2012, 02:38:24 AM
The opposite has been proven, more oil on the bore and rings = a better ring seal = more hp
I run 20:1 but it gets expensive, stick to 32:1 if your motor is stock-ish
I understand the theory, but I have yet to see any relevant proof of this. Everybody seems to refer to tests that were done almost 40 years ago when materials and oil were a lot different than they are today. Do you have any info?
That aside, it's impossible to make a recommendation without any information, like bike, riding style and application.
I have no info just was what some guys were saying down the track, and I myself run 32:1 or sometimes 31:1 And the bike runs like a dream plenty of power, and goes like crazy. Was just wondering what other guys were running thats all. And I don't ride trails very much, bike spends all its time out on the track.
Post by: Stusmoke on September 12, 2012, 08:51:18 AM
Post by: cnrcpla on September 12, 2012, 12:37:29 PM
Post by: 2STROKEREVOLUTION on September 22, 2012, 07:38:28 PM
For the mixture vs power debate. I would think since less oil = more gas, and more gas = more power, then less oil = more power. This may just be made up for in the required re-jetting though.
Post by: factoryX on September 22, 2012, 08:13:06 PM
Post by: Stusmoke on September 23, 2012, 12:27:51 AM
32:1 has been a good mixed used by ALOT of people for a long time, its safe and is often the default mix for stock jets on the MX bikes.
Hey a quick unrelated question to my fellow Aussies is Suzuki still importing their RMs into the country?
Post by: TotalNZ on September 23, 2012, 07:00:40 AM
While we are on the subject of different power output for mixes, I heard around the track and places the expression "leaner is meaner", why do they say that if leaning out the mix doesn't crank out more power? I don't personally believe it is true, I run a bit rich anyways, but I'm just wondering...That saying is referring to the air fuel ratio not the fuel oil ratio
Post by: TotalNZ on September 23, 2012, 07:08:16 AM
It really depends on how you ride. If you are MX racing hard with non-synthetic, go with a mixture in the 40:1 range. I ride trails, sometimes hard, and run full-synthetic Motorex and use 50:1. The manual says I can run up to 60:1 for trail riding. With modern Synthetics 32:1 is old news.You,ve got that backwards, more oil= less fuel= more air ie leaner mixture= more power
For the mixture vs power debate. I would think since less oil = more gas, and more gas = more power, then less oil = more power. This may just be made up for in the required re-jetting though.
less oil= more fuel= less air ie richer mixture= less power
The difference is tiny though. What i think alot of you are forgetting though is that the oil comes out of suspension and pools in your crankcase. Richer fuel oil mix = more oil being spread around your motor. I'd personally never run 50:1 or higher.
I run 30:1 and would go even richer if i could afford the oil.
Post by: scotty dog on September 23, 2012, 01:58:54 PM
Whatever people say I'll stick with 32:1 and may even go richer for my 125 anyway. The 250 is ridden mid range so it could easily run 50:1 I reckon but I'd rather play it safe. The 125 gets wailed pretty decently so I'll definitely stick to the 32:1Don't think so Stu, I may be wrong though
32:1 has been a good mixed used by ALOT of people for a long time, its safe and is often the default mix for stock jets on the MX bikes.
Hey a quick unrelated question to my fellow Aussies is Suzuki still importing their RMs into the country?
Post by: nom de guerre on September 23, 2012, 11:19:12 PM
Post by: msmola2002 on September 23, 2012, 11:58:37 PM
Post by: benji.dojo.3 on September 24, 2012, 07:21:01 AM
You never hear of an engine seizing from too much oil...
Very true.
Prob will keep mine at 30:1 or 32:1. Bike runs great.
Post by: 2STROKEREVOLUTION on September 25, 2012, 12:18:04 AM
It really depends on how you ride. If you are MX racing hard with non-synthetic, go with a mixture in the 40:1 range. I ride trails, sometimes hard, and run full-synthetic Motorex and use 50:1. The manual says I can run up to 60:1 for trail riding. With modern Synthetics 32:1 is old news.You,ve got that backwards, more oil= less fuel= more air ie leaner mixture= more power
For the mixture vs power debate. I would think since less oil = more gas, and more gas = more power, then less oil = more power. This may just be made up for in the required re-jetting though.
less oil= more fuel= less air ie richer mixture= less power
The difference is tiny though. What i think alot of you are forgetting though is that the oil comes out of suspension and pools in your crankcase. Richer fuel oil mix = more oil being spread around your motor. I'd personally never run 50:1 or higher.
I run 30:1 and would go even richer if i could afford the oil.
What you are saying isn't making sense to me.
1) Changing the oil/fuel ratio has nothing to do with the amount of air going into your engine. But reducing the oil does mean more fuel, so yes a richer setting. Then compensate with jetting and the result is more air AND fuel at the same mixture, due to slightly less oil. Will the change from 30:1 to 40:1 be noticeable? Doubt it. Maybe to some pros.
2) I don't see how the oil in my suspension is going to get into my crankcase and pool...
3) The "32:1" was made years and years ago when oil quality was much worse than now. Many people run 60:1 in KTM 2-strokes and get well over 200 hours on a top end. Yes, this is off-road. But I would not hesitate to do 40:1 for MX and save a little $, have less spooge, and that tad better response and power.
Post by: TMKIWI on September 25, 2012, 01:09:29 AM
2) I don't see how the oil in my suspension is going to get into my crankcase and pool...
He is talking about oil IN suspension, not oil in THE suspension.
Post by: TotalNZ on September 25, 2012, 05:43:02 AM
I'll start by saying spooge and throttle response has zero to do with your oil fuel mix and everything to do with your air fuel ratio ie your jetting.It really depends on how you ride. If you are MX racing hard with non-synthetic, go with a mixture in the 40:1 range. I ride trails, sometimes hard, and run full-synthetic Motorex and use 50:1. The manual says I can run up to 60:1 for trail riding. With modern Synthetics 32:1 is old news.You,ve got that backwards, more oil= less fuel= more air ie leaner mixture= more power
For the mixture vs power debate. I would think since less oil = more gas, and more gas = more power, then less oil = more power. This may just be made up for in the required re-jetting though.
less oil= more fuel= less air ie richer mixture= less power
The difference is tiny though. What i think alot of you are forgetting though is that the oil comes out of suspension and pools in your crankcase. Richer fuel oil mix = more oil being spread around your motor. I'd personally never run 50:1 or higher.
I run 30:1 and would go even richer if i could afford the oil.
What you are saying isn't making sense to me.
1) Changing the oil/fuel ratio has nothing to do with the amount of air going into your engine. But reducing the oil does mean more fuel, so yes a richer setting. Then compensate with jetting and the result is more air AND fuel at the same mixture, due to slightly less oil. Will the change from 30:1 to 40:1 be noticeable? Doubt it. Maybe to some pros.
2) I don't see how the oil in my suspension is going to get into my crankcase and pool...
3) The "32:1" was made years and years ago when oil quality was much worse than now. Many people run 60:1 in KTM 2-strokes and get well over 200 hours on a top end. Yes, this is off-road. But I would not hesitate to do 40:1 for MX and save a little $, have less spooge, and that tad better response and power.
As far as the more or less oil goes, you're talking yourself round in circles now. Your motor sucks in a set volume each stroke, if you take fuel from that volume by adding oil then the result is a leaner condition as the oil isn't combustible. the reverse is the same, if you add fuel to the total volume by removing oil then a richer condition is the result. You're right though it wouldn't be noticable power wise between 30:1 and 40:1 i doubt would even show a difference on a dyno. Where i believe you do gain power from extra oil is better ring seal and less friction and heat. Then there are benefits of extended service life.
Post by: 2STROKEREVOLUTION on September 25, 2012, 07:33:57 AM
I'll start by saying spooge and throttle response has zero to do with your oil fuel mix and everything to do with your air fuel ratio ie your jetting.It really depends on how you ride. If you are MX racing hard with non-synthetic, go with a mixture in the 40:1 range. I ride trails, sometimes hard, and run full-synthetic Motorex and use 50:1. The manual says I can run up to 60:1 for trail riding. With modern Synthetics 32:1 is old news.You,ve got that backwards, more oil= less fuel= more air ie leaner mixture= more power
For the mixture vs power debate. I would think since less oil = more gas, and more gas = more power, then less oil = more power. This may just be made up for in the required re-jetting though.
less oil= more fuel= less air ie richer mixture= less power
The difference is tiny though. What i think alot of you are forgetting though is that the oil comes out of suspension and pools in your crankcase. Richer fuel oil mix = more oil being spread around your motor. I'd personally never run 50:1 or higher.
I run 30:1 and would go even richer if i could afford the oil.
What you are saying isn't making sense to me.
1) Changing the oil/fuel ratio has nothing to do with the amount of air going into your engine. But reducing the oil does mean more fuel, so yes a richer setting. Then compensate with jetting and the result is more air AND fuel at the same mixture, due to slightly less oil. Will the change from 30:1 to 40:1 be noticeable? Doubt it. Maybe to some pros.
2) I don't see how the oil in my suspension is going to get into my crankcase and pool...
3) The "32:1" was made years and years ago when oil quality was much worse than now. Many people run 60:1 in KTM 2-strokes and get well over 200 hours on a top end. Yes, this is off-road. But I would not hesitate to do 40:1 for MX and save a little $, have less spooge, and that tad better response and power.
As far as the more or less oil goes, you're talking yourself round in circles now. Your motor sucks in a set volume each stroke, if you take fuel from that volume by adding oil then the result is a leaner condition as the oil isn't combustible. the reverse is the same, if you add fuel to the total volume by removing oil then a richer condition is the result. You're right though it wouldn't be noticable power wise between 30:1 and 40:1 i doubt would even show a difference on a dyno. Where i believe you do gain power from extra oil is better ring seal and less friction and heat. Then there are benefits of extended service life.
You missed some stuff and read my post wrong.
1) Oil mixture DOES affect spooge. Think about it, if you had no oil, there would be no spooge, even with a rich mixture. Because it is the OIL that causes spooge. Less oil will have less spooge. Jetting likely has a much bigger effect than a small change in oil ratio, but oil ratio affects it. Since the oil isn't creating your power, it is essentially blocking the combustion process, remove some and response may increase.
2) Read my post again, I mention jetting at the same time as changing mixture. Basically, to picture it more easily, you have an air/fuel mixture and an oil percentage. Lower the oil and your air/fuel goes up. More air/fuel means more power.
3) If there is so much oil it is becoming spooge or pooling,then it is not helping with ring seal and friction.
How the oil mixture ratio creates a friction vs cumbustion plot would be interesting. What ratio creates the best power? That would have to be experimentally tested.
For me, I'll save the money and have fine reliability at 50:1.
Post by: 2T Institute on September 25, 2012, 11:00:25 PM
OIL doesn't cause spooge, it is a by product of incomplete combustion. Poor jetting and ignition causes spooge.
Post by: Stusmoke on September 26, 2012, 03:30:19 AM
Post by: TotalNZ on September 26, 2012, 05:47:02 AM
Your engine won't ingest a set volume of air each stroke, it changes with throttle position and rpm. In band and WOT will ingest more than the geometric cylinder volume.True true, i should've worded it more carefully, was trying to think of a way to explain some of what 2STROKEREVOLUTION seems to be misunderstanding.
OIL doesn't cause spooge, it is a by product of incomplete combustion. Poor jetting and ignition causes spooge.
Post by: TotalNZ on September 26, 2012, 05:48:35 AM
Post by: arnego2 on September 26, 2012, 03:28:22 PM
I mix @ 25:1 and have zero spooge and about 2mm of premix pooling fallout in the crankcase.
Post by: scotty dog on September 26, 2012, 09:52:29 PM
I have Zero spooge and nice plug readings at 30:1 because my jettings spot on and if you don't have oil pooling in your crankcase then you're in big trouble.Me too....30:1 and not a hint of oil any where
Post by: cnrcpla on September 27, 2012, 12:37:12 AM
Post by: _X_ on September 28, 2012, 02:51:38 AM