Mix ratios

[jolly green thumper]

Using Klotz R50 synthetic oil. Can I run a leaner mixture other than the recomended 32:1. Would 40 or 50 to 1 work without any engine problems. Dealer said it "should be" OK. Has anyone tried these ratios and what where the results.

[Polar-Bus]

I've been running Klotz R50 full synthetic @ 42:1 for almost 20 years never had a mixture related engine failure yet......

[Arigato]

40:1 Yamalube. 

[Paul]

Amsoil @ 100:1 with no issues for 3+ years.

[Timbowe]

Amsoil Sabre Pro 100:1 in all my 2 strokes for the last 20 + years. Why clog up your gas with all the extra oil when you dont need to?

[gowen]

I ran Bel-Ray MC1 @ 50:1+. Could have ran less oil, but I also ran super high RPM's drags with a PVL and ended up locking it up. Ran 32:1 after that. Figured a little oil couldn't hurt @ 8000 rpms.

[Polar-Bus]

Some of you guys run 100:1 ratios?!!!!!!!

Well to each his own.  I don't care how good the oil is, 100:1 is living on the edge IMO......... and I guess my next question is why?

[hughes]

40:1 Yamalube. 

Yamalube 2-R @ 32:1. Yamalube 2-R is the best.

[gowen]

Yamalube 2-R @ 32:1. Yamalube 2-R is the best.

Excellent oil. I ran it in my old YZ250 forever. I also ran 2-R + 2-W in my GP1200R waverunner. Which ever was available at the Yamaha dealership. lol

[FuriouSly]

Yamalube 2R 40:1  Not too expensive and you can get it in a pinch just about anywhere that sells MX parts.  Sly

[hughes]

You will find that the Yamalube 2-R will keep you engine clean. You guy's need to try Yamaha's Ring Free.

[KXcam22]

I raced for years at 85:1 with Belray MC-1 but now I use a tame 60:1.  My Yamaha outboard asks for 100:1.  IMO lean with good oil is where it's at.  Cam.

[KXcam22]

Polar,
  You asked why.  Main reason is that oil burns at a much hotter temperature than gas. If your oil can deliver sufficient lubrication at a leaner ratio then your engine will run cooler since it is burning less oil.  Cam.

[Polar-Bus]

I raced for years at 85:1 with Belray MC-1 but now I use a tame 60:1.  My Yamaha outboard asks for 100:1.  IMO lean with good oil is where it's at.  Cam.

I am by no means arguing, so don't take my posts as just that, but the reason outboard and watercraft engines can tolerate a 100:1 oil ratio is #1, there is NO dirt/dust on water, #2)  the relative rpm loading of all marine 2 strokes is no where near the same levels as say a 2 stroke MX bike. Snowmobiles are injected at a rate of about 80:1, same reasoning, there is no dirt/dust on top of snow. I respect your decisions as far as mixing, but like I commented, it just seems to be engines being run on the edge of "safe" for a difference of a few oz. of oil per gallon..... 

[Paul]

It's all about 'shear strength'. The shear strength of a modern synthetic is what allows you  run such low amounts of oil and continue to provide more than adequate protection. In case there are those reading this thread that don't know what shear strength is, it is simply an oil molecules ability to resist being 'torn' by the forces within an engine.

I would lay odds that a quality oil such as Amsoil, used at 100:1 provide more protection than Yamalube @ 32:1. I've run my 500 and raced it WFO (open desert - LOTS of dust, LOTS of extreme heat ) and never had a failure @ 100:1. Hell Glamis can't even kill this thing @ 100:1. All that 32:1 , 20:1, 24:!, etc... oil ratios are from way back in the day when people ran a conventional 2 stroke oil and HAD to run those ratios to provide the necessary protection to the big end bearing. Those ratios are quite simply based on tradition, not on a hard fact that they are needed with modern synthetics.