250 2 smokes premix question

[TheFro#74]

Hey I recently bought a 94/95 rm250 and i havent had it running yet because of a blown stator, I bought some motul factory line fully synthetic premix and was wondering what ratio I should run it at should it be a different ratio than non-synth or not.

[DK662]

I used to run that stuff 50:1 In my 02 rm250. Im was in the c class though. If your a b or a rider probably run 42:1. I would run 40:1 or so if it was conventional oil.

[TheFro#74]

ok thanks i want to run it slightly on the rich side so would 40:1 be reliable with this premix?

[ShackAttack12]

Ideally, its however much oil you need for a pool to build up on the bottom of the crank case. Since you can't figure that out easily, 32:1 is a good number.

[TheFro#74]

k thanks ill have a play around but ill probably end up running aound 32:1 since ive seen many people from aound the internet recomend it as a baseline

[Stormz]

I've only ever ridden two strokes, and I always mix at 40:1. There's a lot if stuff to take into account though. If you're not racing then 50:1 is absolutely fine. 32:1 is way too rich for most bikes. I bet shack fouls plugs out the ass, especially with how he never revs the bike past like 3,000 rpm

[ShackAttack12]

I've only ever ridden two strokes, and I always mix at 40:1. There's a lot if stuff to take into account though. If you're not racing then 50:1 is absolutely fine. 32:1 is way too rich for most bikes. I bet shack fouls plugs out the ass, especially with how he never revs the bike past like 3,000 rpm

I have never fouled a plug because my bike is jetted properly.

[shawn1331]

I've only ever ridden two strokes, and I always mix at 40:1. There's a lot if stuff to take into account though. If you're not racing then 50:1 is absolutely fine. 32:1 is way too rich for most bikes. I bet shack fouls plugs out the ass, especially with how he never revs the bike past like 3,000 rpm

I have never fouled a plug because my bike is jetted properly.

This^ I don't race and ride a 125 at 32:1. Never fouled a plug in my life, also my jet ski is at 32:1 and never fouled a plug. My snowmobiles fouls plugs when it's hot but thats not an oil issue.

[rgaede]

I change a plug once a year in my two strokes because they just wear out. Use whatever mix is recommended for the oil, if no recommendation is listed on the oil I personally go to 32:1. Just jet for whatever mix your running and you should be fine. Remember, you can foul a plug and not have enough oil, because you are getting too much gas and not enough air into the system. I've seen some of my buddies who were fouling plugs in bikes jetted for 32:1 by running 40:1, and then making the problem worse by going to 50:1. For Motul, I would jet for and run 32:1.

[dylan22]

40:1 which is just 250ml per 10 litres. easy as. GE racetune dyno'd my YZ250 and this ratio gave us the best result with motul 800.

[Boblob801]

I ran 32:1 in my cr125 only fouled a plug once and It was because the bike was idealing while I was opening a gate.
Many mechanics have told me it wont foul a plug unless you leave it idealing to long.

[Stormz]

I'm still going to run 40:1

32:1 just seems like a waste of oil if nothing else.

[mbork-1]

I'm still going to run 40:1

32:1 just seems like a waste of oil if nothing else.

lol 32-1 is perfect
just goons when see their exhaust, think they mix too much oil
just rev bike more

[ShackAttack12]

Alright, let me explain.

The goal of premix ratios is to maintain a certain amount of oil in the engine under normal operating conditions. This is why some places recommend different premix ratios depending on what kind of riding you do and, mainly, where in the rpm range you ride the bike most often. The amount of "stray oil" in an engine drastically decreases with an increase in rpm. Thus, a 2-stroke engine that normally operates around 4000-6000 RPM's requires a higher premix ratio than one that normally operates at 8000-10000 RPM's. In fact, the oil requirements scale quite nicely with the premix ratio depending on the operating conditions. So if your engine requires a 50:1 premix ratio at 5000 RPM's to maintain a sufficient amount of "stray oil" in the motor, then at 10,000 RPM's it will require close to 25:1 premix ratio.

Here is a common misconception: Higher quality oils require less quantity of oil in the gas. You can not substitute quantity with quality.

The most ideal setup would be oil injection system that injects oil at precise rates depending on RPM.

[Ih8Hondas]

We've been running Maxima SuperM, which is supposed to be crap oil according the internetz, at 40:1 for several years in our race bikes and only had to go through one bottom end. And it was probably more the fault of the rider than the oil or premix ratio. I have noticed that it seems like there's more wear on the pitons and stuff when we overhaul our bikes now than when we would run the old Silkolene stuff.

I'm thinking about getting my own jug and running Castor927 in mine and my brother's bikes since we actually ride them properly. Plus it smells amazing. The only reason we run SuperM is because my dad never rides and can't hold onto his bike when he does, so he lugs it around all day.