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What octane?

S
Nov 30, 2007
196
5
18
Meridian, Idaho
I am trying to figure out what octane I should be running so that I am not throwing away money or hurting my low end throttle response with to much octane. I am running a bd rg kit. I am running 9 pounds at 5,000 feet and 10.5-11 at 8,000 feet. Sled is an 07 M8. It is easiest for me to do a blend of 110 and pump.

I am used to using this calculator for 4 stroke yamahas. http://www.ty4stroke.com/viewtopic.php?t=23214 who here is smart enough to convert this over to 2-strokes? I'm not.
 

backcountryislife

Well-known member
Lifetime Membership
Nov 26, 2007
10,893
7,413
113
Dumont/Breckenridge, CO
System to system, kit to kit, sled to sled, there's too many options/ variables to give you an exact. I'd guess that 100ll would be more than you'd need, but start a bit heavy on octane, and lean on it till you hit the sensor, then you know to add a touch more.


This weekend I saw a guy on straight 100LL at 8psi, a guy using 100ll for 12 psi, and myself, running 12.5 and only mixing 1 gal of 116/ tank of 91 (probably 1.3 gal/ tank since I don't run it all the way dry each day)

The det sensors are rather sensitive, it's pretty easy to find the line, then back off a bit.
 
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