30:1 or 20:1 ???

Joined
Sep 9, 2006
Messages
805
Likes
0
#1
Ok, like some of you know i just got a 1983 KX250. The guy before be said he mixed it to 30:1. Well... I decided to read some of my Clymer service manual. And it said for my bike to mix it to 20:1. Now..

What should i mix it to? 30:1 or 20:1? They mention those but the 20:1 is for 1982 - 1983.

I just wanted to make sure because i needed to mix some gas...

Thanks!
 

Rich Rohrich

Moderator / BioHazard
Joined
Jul 27, 1999
Messages
22,724
Likes
529
Location
Chicago
#2
If you are using good quality oil then 32:1 (1 pint of oil in 4 gallons of fuel) will work well for most situations.
 
Joined
Sep 9, 2006
Messages
805
Likes
0
#4
Okey. will do... AND my mom bought 87 octane (regular) gas...i know your suppoesd to buy the good stuff, but this is all i got... besides running like poo will it cause loss of life for anything? like the topend? i dont care as much for the sparkplug but yeah..

Thanks, ill mix it at 32:1
 
Joined
Mar 12, 2001
Messages
865
Likes
0
#5
Moparman1539 said:
Okey. will do... AND my mom bought 87 octane (regular) gas...i know your suppoesd to buy the good stuff, but this is all i got... besides running like poo will it cause loss of life for anything? like the topend? i dont care as much for the sparkplug but yeah..

Thanks, ill mix it at 32:1
You should be ok with 87 octane short term, but pay close attention to any knocking noise/ping-ing/pre-detonation when you're riding.

Most bikes require 95+ octane, but my 05 YZ 250 runs just great on 94 Sunoco.
 
Joined
Sep 9, 2006
Messages
805
Likes
0
#6
Mine only requres 90+.... So tommarrow my mom is going to buy me some of the higest stuff.. (whatever that is) Can i mix that with whats in it now.. or emptyy the tank and put the good stuff in it... I was thinking 87 + 93 would equil out at 90 :cool: .. we'll see
 
Joined
May 9, 2007
Messages
104
Likes
0
#8
Moparman1539 said:
Mine only requres 90+.... So tommarrow my mom is going to buy me some of the higest stuff.. (whatever that is) Can i mix that with whats in it now.. or emptyy the tank and put the good stuff in it... I was thinking 87 + 93 would equil out at 90 :cool: .. we'll see
It won't work that way. Octane isn't linear. You'll end up with something closer to 88-89 octane.
 

Rich Rohrich

Moderator / BioHazard
Joined
Jul 27, 1999
Messages
22,724
Likes
529
Location
Chicago
#9
Filthy_McNasty said:
It won't work that way. Octane isn't linear. You'll end up with something closer to 88-89 octane.
It doesn't work your way either. You won't know what octane you'll end up with, but it's unlikely to matter either way.
 

Rich Rohrich

Moderator / BioHazard
Joined
Jul 27, 1999
Messages
22,724
Likes
529
Location
Chicago
#11
jdc9q8 said:
just curious, what way does it work?

There is no simple math way to determine what octane number will result from mixing two different fuels. People who tell you otherwise are mistaken.
 
Joined
Oct 14, 2006
Messages
103
Likes
0
#12
Rich Rohrich said:
There is no simple math way to determine what octane number will result from mixing two different fuels. People who tell you otherwise are mistaken.
oh because with my new bike ( 02' KX125) it has been modded by Pro Circuit to have a higher compression. So the previous owner told me that i had to run really high octane (110) and semi senthetic oil. I'm using Yamalube 2R which is fine, but my dad only could find 114 octane. So he mixed it 87 octane. he said it would be fine but i had my doubts. but since its like 6 dollars a gallon and i'm not paying for it (yet :nener: ) i didn't say anything.

is that ok?
 
Joined
Feb 26, 2007
Messages
187
Likes
0
#13
mix 32:1. 20:1 is alot of oil. Your regular octane fuel won't be too bad. Just don't use it for long. I use 94 octane in my bike. runs great
 

Rich Rohrich

Moderator / BioHazard
Joined
Jul 27, 1999
Messages
22,724
Likes
529
Location
Chicago
#15
headshot347 said:
is that ok?
I have no idea what PC did to your engine so I have no idea if it's OK. All you can do is test it and find out.