2 Stroke Mixing Ratios Question

5/1/2019 10:52am
Just got a 2003 KX125. The Manual Calls for 32:1 mixture. Is that what I need to do?
My 2017 TX300 Calls for 60:1. I'm using Motorex 2T Synthetic

What do you guys run in a 125? Engine is stock
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BR8ES
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5/1/2019 10:55am
32:1, especially in a 125 unless you ride around like an old arse granny. Be prepared for the onslaught of 50:1 crew, etc.
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BR8ES
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5/1/2019 11:01am
Where's Barnett when we need him? He'd know.
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MPJC
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5/1/2019 11:02am
For a 125 32:1 is probably ideal. I sure as hell wouldn't go to 60:1. When I had a 125 and a 250 I just ran 40:1 in both with good results. Jetted right (or even better, with a Kehin carb) the TX 300 would be happy with 40:1.
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zehn
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5/1/2019 11:05am
As long as you're using a clean burning, high quality modern 2T oil, you really can't go wrong with 32:1. You could probably get away with 50:1 but there's really no reason to do that. Keep in mind that your jetting will need to change when you change ratios

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kb228
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5/1/2019 11:08am
Castor 927 @ 32:1. Jet accordingly. Shouldnt have any problems.
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MxKyle (MD)
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5/1/2019 11:17am
Been mixing at 50:1 since... well, lets just say 'a long long time' with no oil related failures. This included a short pro career. Modern oils lube plenty and the higher the oil content the hotter the bike runs.

--KT--
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77Moto
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5/1/2019 11:22am
Max RPM and time WFO determine the best ratio.

32:1 is good. Jetting doesn't change much or is even noticable unless switching extreme ratio gaps and even then its meh.

I run 20:1 in my Kart. Klotz. Smells yummy.
I run 40:1 in everything else.

Lean ratio recommendations are for the EPA and emissions retards. And of course if your engine wears out quicker, you buy more parts.
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Falcon
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5/1/2019 11:23am
Make sure Motorex is applicable for ratios as low as 32:1. It should say on the bottle. Some oils are designed for thinner dilution ratios, and Motorex is one of those brands that has the quality to get away with it.

That said, I agree that a 125 should be around 32:1 for most applications. I've run Yamalube, Maxima K2 and Bel-Ray H1R at 32:1 in lots of 125s with great results.
zehn
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5/1/2019 11:29am
kb228 wrote:
Castor 927 @ 32:1. Jet accordingly. Shouldnt have any problems.
Unless you're pro speed, Castor 927 doesn't really burn all that clean
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5/1/2019 11:34am
32:1 using 100% AvGas and Maxima Super-M on my 2004 KX125. I ride it like you should, ringing its neck all the time.
kage173
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5/1/2019 11:42am
The KTM/Huskys run differently than an old school KX. I wouldn't go near 60:1 no matter what oil you use. Why not start at what the manual calls for. Then move from there as needed. Personally, I'd max out at 40:1.

I run 60:1 w/Motorex on my KTM 250SX. I run 32:1 on my daughter's KX100.

* In my experience AvGas chews up the hoses on a bike. I used it for about a year until my mechanic friend bitched me out as he fixed my bike.
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jeffro503
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5/1/2019 11:44am
I'm running 36:1 with 927 , 1/2 VP 110 and half 92 clean fuel in my 125. I'll be running that same mix in my TC 250 as well. I just switched from a 40:1 mixture to test out , and I could tell slightly that the 36:1 mix leaned it just slightly , especially at the very top. On the 125 I'm running the blue needle ( I think? ) with a 42 pilot and 195 main , and in these temps it's jetted about as perfect as possible. I'm running a high compression head as well , with nice exhaust , V-force , modified PWK with STIC mod and opened up air box.

Same mods on the TC 250 , minus the STIC mod and using a Rad valve instead of V-force. Going to start off with Blue JD jetting needle , 42 pilot and 172 main and go from there.

jeffro503
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5/1/2019 11:46am
kage173 wrote:
The KTM/Huskys run differently than an old school KX. I wouldn't go near 60:1 no matter what oil you use. Why not start at what the...
The KTM/Huskys run differently than an old school KX. I wouldn't go near 60:1 no matter what oil you use. Why not start at what the manual calls for. Then move from there as needed. Personally, I'd max out at 40:1.

I run 60:1 w/Motorex on my KTM 250SX. I run 32:1 on my daughter's KX100.

* In my experience AvGas chews up the hoses on a bike. I used it for about a year until my mechanic friend bitched me out as he fixed my bike.
I personally never like the power output of AV gas. I'm not sure what the differences are , but I just didn't care for the way it ran. Been about 20 years , so my memory is a little foggy.
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BR8ES
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5/1/2019 11:58am
Klotz SuperTechniplate or Ravenol, 32:1, 100ll avgas, jetted accordingly, 2019 TC125... bike runs fantastic.
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5/1/2019 12:01pm
32:1. Castor will gum up your power valves, Max Power RPM recommended Yamalube 2TR to me, runs great.
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peelout
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5/1/2019 12:07pm
i always ran 40:1 on my Yamahas. nothing less than 50:1 for a KTM.

never could get 32:1 to run worth a shit.
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Ing
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5/1/2019 12:08pm
50:1 in every 2 stroke for me. Really what ever the oil specifies. They know how their oil performs.
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toomanykaws
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5/1/2019 1:34pm
One benefit of Av gas 100LL is the lead. Its not the cleanest fuel but the lubrication of the lead doesn't hurt. 40-1 on most my two strokes with Redline oil. Easy to get by the gallon. Burns well. 150 hrs on a piston and still was usable on a 200. Not much carbon. Skirt was like new all the way around.
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BobPA
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5/1/2019 1:49pm
I just sold a full race gas engined 2003 KX125 last year. I ran VP U4.4 just cause. Mixed it at 32:1 with absolutely no issues. Before I went to the full race gas engine, I ran it 40:1...mostly because I did not want separate gas cans between my 125 and 250. Always ran my 125’s at 32:1 because you pound the shit out of them.

Any name brand oil between 32:1 and 60:1 is fine....
Sierra Ranger
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5/1/2019 1:53pm
I run VP C-12 mixed 50/50 with high-octane pump gas and Honda 2-stroke oil at 50:1 in my 2004 RM250- no problems.
I was getting a lot of oil blubber out of my exhaust at the lower ratios, and this seemed to improve that. Course, I am a Vet practice rider and I'm not running redline all the time.
captmoto
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5/1/2019 3:44pm
32:1 using 100% AvGas and Maxima Super-M on my 2004 KX125. I ride it like you should, ringing its neck all the time.
That's my poison right there for my YZ465.
brocster
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5/1/2019 8:10pm
different strokes for different folks... not sure some people understand a rich mixture vs a lean mixture it seems.
FeetUp
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5/1/2019 8:31pm
Bel-Ray MC1 50:1 Whistling
5/2/2019 6:55am
77Moto wrote:
Max RPM and time WFO determine the best ratio. 32:1 is good. Jetting doesn't change much or is even noticable unless switching extreme ratio gaps and...
Max RPM and time WFO determine the best ratio.

32:1 is good. Jetting doesn't change much or is even noticable unless switching extreme ratio gaps and even then its meh.

I run 20:1 in my Kart. Klotz. Smells yummy.
I run 40:1 in everything else.

Lean ratio recommendations are for the EPA and emissions retards. And of course if your engine wears out quicker, you buy more parts.
The whole 50:1 thing was due to leaf blowers and string trimmers.
Wanna make a chainsaw crank last? Up the oil to 32:1.

50 is pretty lean when turning 14-15K.
5/2/2019 7:03am
kage173 wrote:
The KTM/Huskys run differently than an old school KX. I wouldn't go near 60:1 no matter what oil you use. Why not start at what the...
The KTM/Huskys run differently than an old school KX. I wouldn't go near 60:1 no matter what oil you use. Why not start at what the manual calls for. Then move from there as needed. Personally, I'd max out at 40:1.

I run 60:1 w/Motorex on my KTM 250SX. I run 32:1 on my daughter's KX100.

* In my experience AvGas chews up the hoses on a bike. I used it for about a year until my mechanic friend bitched me out as he fixed my bike.
Fake news. The SDS on av gas proves there is nothing in it other than standard ingredients of any race fuel, or any other fuel. If you look at the SDS for the old 110/130 and 115/145, they were basically what VP "Air Race" is today.

The FAA isn't going to allow something that could make planes fall out of the sky.
5/2/2019 7:15am
I've always ran 40:1 on everything just for the simplicity of always mixing a half qt oil in a 5 gal gas jug. And I can get it jetted well on any bike I've ever owned.
captmoto
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5/2/2019 11:00am
kage173 wrote:
The KTM/Huskys run differently than an old school KX. I wouldn't go near 60:1 no matter what oil you use. Why not start at what the...
The KTM/Huskys run differently than an old school KX. I wouldn't go near 60:1 no matter what oil you use. Why not start at what the manual calls for. Then move from there as needed. Personally, I'd max out at 40:1.

I run 60:1 w/Motorex on my KTM 250SX. I run 32:1 on my daughter's KX100.

* In my experience AvGas chews up the hoses on a bike. I used it for about a year until my mechanic friend bitched me out as he fixed my bike.
Ran it in my 05 CR250 for 3 years. Run it in my YZ465. Ran 5 gallons through my FC450. Never had a fuel related problem. The only time I ever had a problem was with pump gad eating the fuel line on my YZ400F and really clogging the carb, After I got it running I put alcohol resistant fuel line for Motion Pro and never had a problem.

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