Mine will usually run worse when it's not set to premium no matter what gas I put in it.

 

Your sled with run a little cooler with 91, as far as the switch in Premium it advances the timing 3 degrees(from regular)...in regular it retards the timing 3 degrees(from Premium), that's about it...all things aside the only difference is in the fuel, not performance of the sled. Before I did any mods I ran it with regular gas, not to keen of paying more for gas...now after mods I have to run Premium[] If I had the option I would still be running regular.[]

 

I didnt really notice any gains at all with the premium switch.

 

Before the head change, I tried both settings, could not tell a difference. The times may have quickened but the seat of pants feel was not there.

 

I haven't ever noticed much of a difference but i run premium any ways just a couple extra dollars.

 

on my xcsp 800 It makes a huge difference when going from 87 to 93 octane with the switch. so i would say a large difference.

 

are you talking about a large power difference Polaris800? Like can you actually feel the change? Interesting....

 

I have an 04 800 RMK and noticed NO power difference between regular and premium, maybe it's just me?

 

My 2002 600sp was 1 MPH faster in the 1/4 mile with the switch on premium.

 

i only run 92 octane with added octane boost and i leave the switch on regular

 

It will run better in premium. The switch changes the ignition timing. It wont run as good.

 

From I can find and to who I talked to, the gain is only above 7000 rpm, till then timing is the same.

 

Whilr running premo fuel and the swithch to premo you have less of a chance to have detonation and the switch also compresses the fuel more before it burns it so you have a better explosion in the chambers. The main goal for this system is to make the motor more reliable.

 

How can the switch compress the fuel more. The switch does not lengthen the stroke. The piston travels the same no matter where the switch is. It changes the timing curve, nothing more nothing less.

 

...

I just bought my sled last friday, and the Polaris tech told me:

The Fuel Octane switch is only availabe on machines with digital ignition timing. It simply advances the timing two more degrees and lights up the PREM ONLY light on the Tach.

That info came straight from the tech.

On an aside, I understand I can install this switch on my 550 as I use the same ignition system as the Pro X 440, I would just have to find out where the inputs are to the ignition system, and be sure that no detonation would happen, on premo fuel, with the extra timing.

-Steve

 

XCR 440 You are right, I worded that wrong. It does fire it up at a point wher it is just past the TDC instead of a little later so in reality the fuel air mixture is at a higher rate of compression when burned.

 

Ahhhh, now I understand. Does it not make a couple of hp more when running the premium.
I was told that the 700's run better on premiun than regular.

 

Not really more hp but better throttel response on premo fuel. I had an 03 RMK 700 and all I ran was a 25/75 race/regular mix and it was awsome, I would have never sold that sled, but I broke the chassis in half on a drop and just sold it for parts. The 700 rocks.

 

I was told it advances the timing by 2*. Is this try. What it do if you changed the timimg yourself.

 

I don't think you can change the timeing yourself, unless you got a hack for the polaris CDI Box and are able to write your own ignition curve. and if you are able to do that then you should be out there makeing big bucks. Because their is a large market for this sort of thing.

 

Like what every one has said it advances the timing in your ignition. I'm not sure how much but its probably not more than two degrees. Each degree usually raises the horsepower by 1. So it will be around 2 horsepower gain, not too noticeable. Normally you would have to take out the timing key and replace it with a new one which is down on the crankshaft. The Polaris uses electronics in this case to change the timing. If you put it to premium you'll want to run premium gas. If you don't, after a while it could cause detonation. Heres a link to see where the timing key is located and how you change a normal one.
http://www.arcticchat.com/forums/index.php?showtopic=14335

 

I have the prem only light turn on when my key is in the first position but I doubt that my sled even has the timing adjusting with that switch because its a fan and the speedo with the prem light in it came off a 2001 xc 600.

 

huh? you guys just tought me somthing new, i didnt think i was ever supposed to run anything but premium. why would you run anything but ? cheaper in the long run?