Trust me I've searched through alot of pages with no luck.

My bike will soon have the Bob B Ignition Advance, Wileyco w/Srinath Flange (Choker), and no re-jet yet.

So what octane is the best for performance (not power, but reliabilty) and I've heard some octanes run cooler, is that true?

THANKS, BigTwin

Lower octane runs cooler.

Higher octane is only necessary if you "do" something with it e.g. advance timing (which you did).  I believe higher octane (somebody correct me) has a slower flame front.

Since you are running the choker flange and no rejet, I would think that higher octane is probably not needed as long as you're not pinging.  I don't know how much the advancer puts in there though.  If it's only a few degrees, I wouldn't worry about it unless you start hearing popcorn

Quote from: V8PintoI believe higher octane (somebody correct me) has a slower flame front.

You are correct. In effect you are "retarding" your timing by running a higher octane.

Well I advanced my timing 12 degrees, so should I go with high octane?

All we have in Ohio is 87,89,93 so no 91. What is best?

THANKS, BigTwin

Run the 87.

ya octane is the resistance to combustion.  It is so you can have the gas compressed more with out it combusting unless there is spark.  to a point of course.

Is there a greater chance of preignition with lower octane?

yes, but I havent had any problems running the low octane, I really dont think you have anything to worry about unless you start to hear some ping knock sounds.

When I was putting on my Bob B advancer earlier today I turned the advancer to the right (meaning while tightening it I rotated it) and I'm not sure if this is a problem? I don't know if it has to be pointing a certain direction?

Bike runs great with it by the way, I also ran out of gas while riding. I pulled over to the side of the road and switched to Reserve, but it ran like crap and only ran for a mile then it died again, is this normal? How long should I put it on prime for? I did it for a few seconds and it started, but a short, I mean short while later it was just bogging down and completely died and wouldn't start back up. Luckily it died at the intersection of my gas station.

What could be my predicament?

And I got 93 octane because this all happened prior to this thread happening, any problems when I switch back to the low octane? This is my first time filling up also, it held 4.9 gallons is that normal?

THANKS to all who replied, BigTwin

I have the Bob B advancer, and my bike runs great with mid-grade (89).  I actually get the worst gas mileage with super (91).  I suppose I ought to try the 87 at some point but I am fine with mid-grade.  Over 2.5-3 gallons it takes to fill, an extra 30 cents won't kill me

Quote from: BigTwinI also ran out of gas while riding. I pulled over to the side of the road and switched to Reserve, but it [...] only ran for a mile then it died again, is this normal?

No.  The ON and RES fuel hoses are probably switched.  (Meaning that you ran your REServe out with the fuel selector set to ON.  Then when you switched to RES you had nothing left.)

Quote from: BigTwinHow long should I put it on prime for?

15 or 20 seconds or so.

Quote from: BigTwinit started, but a short, I mean short while later it was just bogging down and completely died and wouldn't start back up.

That's the perfect time to move the switch to PRIme and leave it there.  But if your hoses are swapped that won't help.  

Quote from: BigTwinThis is my first time filling up also, it held 4.9 gallons is that normal?

The '01+ tank is supposed to hold 5.3 gallons MAX, so that's a pretty good fillup.

PS - I have used 85 octane for most of my 34,000 miles....   :dunno: