best fuel to run?

[denidave]

Hi folks,
I have just bought a yz490 and having been out of the two stroke world for a while I am wondering  what the best fuel to run is?   unleaded of what rating   such as 91-91-98   or am I better off running avgas which I have easy supply to as well?

then which premix oil is recommended to run with it and what ratio seems to be ideal...

bare in mind that price is of no argument as I only ride it when I get a chance so Id rather pay for quality if that's whats recommended.

thanks and I hope this isn't like bringing up religion or politics....

[Rossvickicampbell]

no - but soon you will get 1 million different opinions

I run 98 Ultimate - can't get easy access to avgas and Silkolene Comp 2 Pro SX (I think its called) - basically best I can get from Silkolene.  Quite a few others on the market.  I run 40:1 and haven't had any dramas.

Now - let the fun begin

Rossco

[Mick D]

Fuel Consistency is paramont.
Quality
Bang for buck
Easy to manage
Mistakes and wastage don't suk up your fun tickets
BP ULTIMATE

Ticks all my boxes

[pecrazy]

It may be a myth but I have heard BP ultimate does not mix well with 2 stroke oils.

[bazza]

BP 98 blend 50/50 av gas in BSA
vintage and modern 2 strokes , have 5 running BP 98 woth Motul oil 32.1 never problem and piston and bores all ways look good
 

[John Orchard]

Any 98 octane in a big-bore 2-stroke.

[Rossvickicampbell]

actually have been doing a bit of a back to back thingy with my V8 - and yes lots of inconsistencies in what I am looking at - but likes BP Ultimate more than Vortex 98.

[Lozza]

Hi folks,
I have just bought a yz490 and having been out of the two stroke world for a while I am wondering  what the best fuel to run is?   unleaded of what rating   such as 91-91-98   or am I better off running avgas which I have easy supply to as well?

then which premix oil is recommended to run with it and what ratio seems to be ideal...

bare in mind that price is of no argument as I only ride it when I get a chance so Id rather pay for quality if that's whats recommended.

thanks and I hope this isn't like bringing up religion or politics....

Nooooo it's much worse.  In the big pinger run avgas @20:1 with a castor/synthetic blend oil, unleaded needs a dedicated set up to get the most out of. Avgas will be that little bit more forgiving.

[pokey]

The BEST fuel is what fuel YOUR engine is tuned for
Your mates bike will like something else most likely. if you can get Avgas  then tune it for avagas.

just stick lots of good quality oil in it so it wicks that heat away nice and quick.

[mick25]

I have only tryed vortex 98 , so I no stuff all about this topic .
but on the flip side I've had heaps of hole shots over the years running vortex

[Mick D]

I have only tryed vortex 98 , so I no stuff all about this topic .
but on the flip side I've had heaps of hole shots over the years running vortex

So I have heard, bastardo fukin Kiwis   Nah, good on ya Mick
I hope to get back here latter, but I busy at the moment, trying to catch a cat and put him in bucket
He's already seen the bucket and left me dripping in blood just before he was last seen

[smed]

[/quote]

 busy at the moment, trying to catch a cat
[/quote]

When ya catch the pesky feline mate come to my place & deal with the little bastard that keeps crapping in my garden

[denidave]

Hmm so I'm leaning to the avgas and 20:1, consistency in avgas is meant to be spot on. back 20 years ago we ran it with castrolR30, is that still around and a good thing or what  would be the best castor based oil ?
Bike is fresh from the states and running a flatslide carb/boyesen reed block etc and had head mod and porting work.  was thinking of sorting out the fuel side of things then send it down to Dave at TSP in Melbourne to tune it on the dyno, saves me a lot of mucking around as I don't get many days at home due to working away.

[Rossvickicampbell]

few [people advocate 20:1 - others disagree???  Castrol R30 not as good as the new oils out now.

[denidave]

didn't think it would be as good as the newer oils, any particular oil better on big bores than others? I see some such as motorex recommend 40:1 on 500cc bikes?