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Nick110
03-20-2005, 04:12 PM
i wanted to know if u can run 93 octane on a 12.1 or higher. if not what comp. should i get. and if i need anything else to go with it.
ghak99
03-20-2005, 07:27 PM
12:1 is border line, it depends on your individual motor, gaskets, and cam set up. To be safe, I would get the 11:1 if you wanted to stick with pump gas.
04'400ex'er
03-20-2005, 08:22 PM
11:1 on 93 octane. If you run 12:1 then you need to mix race gas with premium for the best results.
400exrider707
03-20-2005, 10:42 PM
Originally posted by 04'400ex'er
11:1 on 93 octane. If you run 12:1 then you need to mix race gas with premium for the best results.

unless your running a 12:1 wiseco then its ok to run the 93
honduh440
03-21-2005, 01:39 AM
i had a 12:1 JE piston and ran 91 octane on it for 2 years only time it had higher octane was durrnig races never had 1 problem
2muchquad
03-21-2005, 08:24 AM
i run 13.5 to 1 in my yzf mx bike,i run 93 from the pump,never had a problem.:)
400exrider707
03-21-2005, 08:38 AM
Originally posted by 2muchquad
i run 13.5 to 1 in my yzf mx bike,i run 93 from the pump,never had a problem.:)

WOW:huh
Silverfox@C&DRacing
03-21-2005, 08:47 AM
the yfz is a liquid cooled bike that is designed to run higher compression piston on pump gas. Nick 110 if you have a 400ex I would stay around 10.8:1-11.2:1 on pump gas, many factors play a part in this like elevation, temperature, engine design,timing ect...
cals400ex
03-21-2005, 10:08 AM
many say you can run the higher ratios others say no. i run a 11:1 426 with a thin head gasket and no base gasket right off pump fuel. i have never had a problem. i tried race fuel and the bike didn't run any noticable different and i couldn't tell it ran cooler either.
F-16Guy
03-21-2005, 10:12 AM
Originally posted by cals400ex
many say you can run the higher ratios others say no. i run a 11:1 426 with a thin head gasket and no base gasket right off pump fuel. i have never had a problem. i tried race fuel and the bike didn't run any noticable different and i couldn't tell it ran cooler either.
I need it in the dunes, but I didn't fix the squish band problem like you did, so you can probably run a higher CR and get away with it.
Nick110
03-21-2005, 12:20 PM
what if i run octane booster
cals400ex
03-21-2005, 12:52 PM
Originally posted by Nick110
what if i run octane booster


that is not recommended. for more info, do a search.