I recently bought an athena works kit for my yz 125 that claims to have a compression ratio of 14.8:1 and am having difficulty in trying to figure out what octane fuel to use. Where I live the highest octane gas that i can find is 93. Should I try octane boosters or is race fuel that much better?
Fuel for 15:1 compression?
- Thread starter gurt
- Start date
Very few octane boosters actually do very much to improve the fuel. Normally they say it will raise it 10 octane points. What they don't say is that an octane points isn't from 93 octane to 94 octane, it's from 93.0 to 93.1. So you think you're running 103 octane, but you're only getting 94 octane. It makes no sense for the cost to get these negligible increases.
Race gas will be far better, and you will find it well worth your time to find a source for race gas. If you can't find a source, and don't want to order drums of it, you can buy race gas concentrate that you mix with premium pump that truly does boost the octane to that of race fuel. Klotz, VP and others sell it. The cost is similar to just buying race fuel though, so if it is available, simply buy the race gas.
Race gas will be far better, and you will find it well worth your time to find a source for race gas. If you can't find a source, and don't want to order drums of it, you can buy race gas concentrate that you mix with premium pump that truly does boost the octane to that of race fuel. Klotz, VP and others sell it. The cost is similar to just buying race fuel though, so if it is available, simply buy the race gas.
robwbright
Member
- Apr 8, 2005
- 2,283
- 0
You should be able to get race gas somewhere near you unless you live in the desert or alaska. ;) Where are you from? Some here might be able to help you.
It took me awhile to find a distributor, but then I discovered there was one right under my nose - about a mile from my house.
Ask around at the dirt bike shops and such.
I'm at 14.5:1. I'm running a 105 octane very successfully. I have also used 100LL AVGAS a little bit in the motor - before I got the 105. Eric Gorr told me it would be ok if I ran it a bit rich and listened carefully for detonation.
Your results may vary.
It took me awhile to find a distributor, but then I discovered there was one right under my nose - about a mile from my house.
Ask around at the dirt bike shops and such.
I'm at 14.5:1. I'm running a 105 octane very successfully. I have also used 100LL AVGAS a little bit in the motor - before I got the 105. Eric Gorr told me it would be ok if I ran it a bit rich and listened carefully for detonation.
Your results may vary.
Trick, VP, R-Tech and sunnoco are just a few of the more common brands of race gas out there. I have to run trick 114 in my '06 yz 144 even though it says 114 it actually only burns at like 106 so you have to becareful in that respect. I would say probably nothing lower than a solid burn octane level of 103!
Typically what you see or how it's listed: Research Octane (R.O.N.)
What it burns at in the motor how it's normally listed: Motor Octane (M.O.N)
Sometimes they list the anit knock level : R+M/2
Most often you'll just see the research octance advertisted so know your fuel brands before buying.
I know VP and Trick both have websites i'm sure R-Tech does probably even sunnoco. There's a few other brands out there i'm leaving out. Those 4 are the most common brands I see.
Typically what you see or how it's listed: Research Octane (R.O.N.)
What it burns at in the motor how it's normally listed: Motor Octane (M.O.N)
Sometimes they list the anit knock level : R+M/2
Most often you'll just see the research octance advertisted so know your fuel brands before buying.
I know VP and Trick both have websites i'm sure R-Tech does probably even sunnoco. There's a few other brands out there i'm leaving out. Those 4 are the most common brands I see.
MXP1MP said:
How exactly did you come to that conclusion?
well, if you take 144 and subtract from it 114 you get 30 take that 30 and subtract it from the original 144 and add ''06 you get 120 now subtract the 14 remainder from the 114 and you get 106 :)
C'mon Rich I thought you were smarter than that! :moon:
C'mon Rich I thought you were smarter than that! :moon:
- Thread starter
- #7
after looking around today I found out that the only place around me that sells race gas isnt selling it right now. It seems like my only other option is air plane fuel. My friend is telling me that it's 133 octane, which sounds high to me,or is he right? If i were to use the air plae fule would i have to dilute it?
robwbright
Member
- Apr 8, 2005
- 2,283
- 0
MXSparx said:
Been there, done that. . . I've been in a variety of AVgas discussions on here.
Just telling you what Eric told me . . .
MXP1MP said:
You don't know the octane requirement (RON or MON) of his engine so you don't really know if the 101 unleaded fuel will work or not. Just because a fuel has a high MON octane number does not automatically make it a good choice for a two-stroke. The influence of the back end of the distillation curve has at least as much impact on a two-stroke.
