confused

[carpenter]

how come the 250r says 20:1 and yall say 50:1 or 40:1 or 32:1. and whats better synthetic or benol?

[my88r]

Originally posted by carpenter
how come the 250r says 20:1 and yall say 50:1 or 40:1 or 32:1. and whats better synthetic or benol?

those 50:1/40:1/32:1 are because we are using a high grade oil..

i run amsoil dominator @ 50:1 as it formulated to do.

theres many different views on oil brand and ratio.

[carpenter]

so is that what u would recommend? and will all the different oil have they set mixture on them? im new to two-strokes.

[my88r]

Originally posted by carpenter
so is that what u would recommend? and will all the different oil have they set mixture on them? im new to two-strokes.

yep, i use the amsoil..

this is a very beat to death question. many,many, threads on this. do a search you will find all you need. to know about 2 storke oil.:)

[baldathoR]

Klotz 50:1

That's all you need to know.

[88 250r]

ams oil 44:1 thats all you need

[2muchquad]

Maxima 927 32:1,thats all you need to know:D

[trx310R#24]

motul 32:1 thats all you need to know :D :devil: ;)

[RedRider23]

there's a old saying us 2 stroke guys go by....

Lean is Mean!! dominator 32:1

[carpenter]

just the mixture change depending on the diff mods u have vs stock or is it always the same?

[JIMFROMTEXCO]

its all just personal preference, i run 32:1. the 20:1 was for the r back in the 80's but oil has progressed so much since then. what ever you use just make it consistently the same always for your jetting.

[2muchquad]

Yeah but independent test have shown that at 18 to1 (which i dont run) actually makes almost 3hp more than the same engine at 40 to 1.These were conducted on a yz250 motor.3hp is pretty significant imo.The extra oil helps increase compression by reducing blow by.Im currently running 24:1 in my 490 hybrid just for something to do and so far its running crisp and not oil fouling plugs.;)

[my88r]

and this is where the oil wars begin...

[mxduner]

let me add to the confusion:devil:


approximately 42:1, thats 3 ounces of oil to 1 gallon of gas, just makes it easy for me to remember:D

thats amsoil dominator in my 310 and my yz 250

[mxduner]

Originally posted by 2muchquad
Yeah but independent test have shown that at 18 to1 (which i dont run) actually makes almost 3hp more than the same engine at 40 to 1.These were conducted on a yz250 motor.3hp is pretty significant imo.The extra oil helps increase compression by reducing blow by.Im currently running 24:1 in my 490 hybrid just for something to do and so far its running crisp and not oil fouling plugs.;)

where can i find an article on this? i find that interesting. who did this testing?

[2muchquad]

I will try and find it,i think i read it in a link over on everything2stroke.com,i'll look for it...

[2muchquad]

here..i got this over on thumper talk

I have run Dyno tests on this subject, as a school project in Tech School. 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 (an '86 YZ 250) 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. 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.

The bottom line? Choose a mix ratio that is adequate for your needs, and jet accordingly. You don't fix plug fouling and spooge by adjusting your mix ratio.

This is an interesting read that also supports my "more oil is better" claim.

http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf

[atvmxr]

Originally posted by 2muchquad
We used specially calibrated jets to ensure the fuel flow was identical with each different ratio... 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.

umm that seems like a conflicting story to me, of course if you dont rejet the bikes not going to run effectively :rolleyes:

[Fear250r]

I don't know whether or not anyone has brought this up or not, but would a particular oil be better for big bores? Just figured I'd ask.