91 octane or ETH settings

[hopewell64]

Does any one know exactly what happens between the two settings. I am running a power addiction 13.6 head and a clutch set up. I also am running a mixture of 91 octane with about 3 gallons of 100LL avy fuel, at 9000 ft and above. Does the ETH setting retard timing and Richens the fuel. Thanks in advance.

 

[Stewy]

It's always been 4 or 5 % richer fuel with no timing changes. I haven't seen this years on a dyno yet but I'd bet it's the same.

 

[bobback]

Dealer told me to leave on eth setting always; even if running "meth" free gas. As ALL gas has some level of "meth"anol in it.

 

[granto]

Mines never left the premium setting since day one 2000 miles later zero issues still runs great. From what i heard just runs a little more rich on eth setting.

 

[hopewell64]

O.K. thanks guys . Guess I will run on the ETH. setting. Hey BobBack I see you are from Bozeman. Do you happen to know Rich Spalone, I'm headed up there to ride with him next month .

 

[sledneck_03]

I clutched mine for 8300 and then figured out how to change to 91 mode now i rev at 8500 max.

Adds 200 rpm max for me.

Run mine at 91 setting always run fuel that has no ethanol.

 

[bobback]

O.K. thanks guys . Guess I will run on the ETH. setting. Hey BobBack I see you are from Bozeman. Do you happen to know Rich Spalone, I'm headed up there to ride with him next month .

Nope.

 

[overboard]

PCV + Eth = rich bog

I left mine on Eth for break in, with SLP stage 3 kit (PCV).

I was getting what I understand now as a rich bog at ~ 1/2 throttle and ~ 6000 - 6300 rpm.

Changed to 91, bog dissapeared. SLP's PVC run +20% fuel in this setting (throttle position and rpm) and it was just too much with the +5% Eth (for a total of 25% more fuel).

Point being that just to run Eth all the time may have effects with modified fueling.

 

[hopewell64]

Thanks for.the answers guys. The reason I asked because I was riding last week and my sled went into a limp mode because of detonation. So as not risk it, I went back to the Eth. Mode. I'm gonna try a richer mixture of avy. 100ll fuel and back to the 91 Oct. Mode.

 

[Ghislain_83]

I run the same head in my 14 pro... I run on 91 oct. I don't have any problems