Octane

[RykerUSA]

Last summer I took my blue bike out west ('15 ST Limited). I toyed with running different in different tanks of gas. I ran each tank down to fumes before refilling. 92 octane got noticeably better gas mileage then 87 at interstate speeds - that is 26 - 27 miles a gallon vs 32-33 miles a gallon. This seems to confirm what's written above regarding performance and efficiency running lower octane fuel than specified.

Always here to fuel the debate!

[Lew L]

I think that compression ration has a lot to do with proper octane requirement of a motor. Soooooooooo---------

What is the comp. ratio of the 1330 motor?????

Kaos

[BLUEKNIGHT911]

A direct result of running lower octane than recommended by the manufacturer.
Your looking at a destroyed piston from my jet ski. The screw driver is pointing at a compression ring exposed. All 4 destroyed. Direct result of 87 octane instead of 91.
Lesson learned from experience. Just my 2 cents

I would like to know - Brand , year , 2 or 4 stroke , size ......... Thank you .................. Mike

[Gsebring]

KNIGHT911;1219549]I would like to know - Brand , year , 2 or 4 stroke , size ......... Thank you .................. Mike [/QUOTE]

IMG_0133.jpg Kawasaki 12-f 4 stroke 1200cc.
Never can figure out how to rotate pics.

[GOZFST]

A hundred years ago when my wife and I used to road race motorcycles we both ran high performance 2 stokes, she ran a Yamaha TA-125 and I ran a TZ 350 you could melt pistons before you got to the first corner at Brainerd Int'l Raceway or Road America if you used nothing but race gas, BUTT those were the days before computers controlled ignition timing and fuel. 2 degrees before top center was fine anything more aggressive and you'd melt the exhaust edge of the pistons again. Modern technology has done wonders for engine performance.

[Bob Denman]

I think that compression ration has a lot to do with proper octane requirement of a motor. Soooooooooo---------

What is the comp. ratio of the 1330 motor?????
Kaos

12:1

The 990 bikes ran 10.8:1
The 991s gave everything a 12.2:1 squeeze...

[BLUEKNIGHT911]

KNIGHT911;1219549]I would like to know - Brand , year , 2 or 4 stroke , size ......... Thank you .................. Mike

IMG_0133.jpg Kawasaki 12-f 4 stroke 1200cc.
Never can figure out how to rotate pics.[/QUOTE]
Thanks for the info - however ... the last year I could find for this motor in a water craft was 2007 !!! .... what year was your PWC ??? ......... Mike

[Fat Baxter]

Some of you said you run on 91 octane. Where do you get that? Is that a regional thing?

Down here in the Southeast, the options are 87, 89, and 93. Lately, I've been running 89 as an experiment instead of 93, and haven't noticed any issues. Mileage seems unaffected as well.

[Bob Denman]

We only have access to 93 octane up here, and that's what I run.