I'm curious about who does what with their fuel as i read in Performance Bikes magazine that Fontyyy mixes half avgas and half unleaded and i know WhiteBaitNZ does the same.

I've always run mine on plain BP ultimate 98. I'd like to know what everyone else uses, be it for road or race use.

Anyone race or do trackdays on just unleaded pump fuel?
Anyone use 100% avgas?
Is the 50/50 avgas mix mainly for safety?

Ta very much
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After years of moaning about immigrants now i am one...

it all depends on set up mate.

avgas is used when people up the compression ratio by lowering the head volume or when the std set up of the bike was for leaded fuel. my rs is a 98 unleaded bike but is now set to runs avgas, more ultimate performance could be achieved with unleaded race fuel but avgas is used at it helps with jetting and preserving the engine.

the 50/50 mix people use is normally for safety, lets say if someone had lowered there head volume but not all the way down to a avgas volume or was concearned there set up did induce detonation.

i used BP ultimate in all my roadbikes and used it on the track for trackdays. its perfect for std engines as thats what there set up / jetted for.

Safety and longevity, jetting isn't as critical and everything lasts longer as the lead helps lubrication.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread

I always raced on super-plus (98 octane) and it was fine. Made decent power when I got my jetting right!

Used it again last week at a trackday and again it was fine. Slow as a dog cuz it's standard now, but it didn't go bang.
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I got the same bhp and nm reading when i changed from leaded race fuel to unleaded pump fuel . My engine tuner recut my heads and changed the ports to allow pump fuel . The unleaded pump fuel likes bigger jet sizes and it peaks later in the rev range .

I run 87 in mine and would not expect any performance gains with a higher number. With such a low compression ratio (stock), I don't expect to need a higher octane. Pinging and detonation would probably only arise after cutting the heads or other mods which would raise the compression ratio.

Hermit........your not meant to give away my secrets!

My take on the av gas thing is the lead helps with lubrication and the higher octane helps to stop detonation.

Every NSR around me seems to be blowing up minus my one so I'm happy with the 50/50 mix

I think that half the guys that race or do track days seize because of wrong jetting and proper warm up . This gives the two strokes a bad rep !

WhiteBaitNZ wrote:Hermit........your not meant to give away my secrets!

Sorry Bro, i'm on a mish to gather everyone's knowledge so i can stand a chance of hangin with you at Manfeild!

Incidently, where would one go in NZ if they wanted to get some avgas?
I know someone in the Hutt sells high octane race fuel that a drag racing friend buys from - but i dont think its the same stuff. I fully admit to not knowing anything about this subject!
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After years of moaning about immigrants now i am one...