Race gas - what to get?

[queen of spodes]

Has anyone here tried the new VP blend MRX02?  How about the C-9 premixed?   

Any other blend I should get if not one of those?

[beaner]

Why do you think you need race fuel?

[Jeram]

you will only need race fuel if your motor actually requires it.


Modified motors:
-high comp motor?
-advanced ignition?

stock:
getting detonation and jetting isnt helping (as seen by some TM racing owners)

on a stock motor, unleaded race fuel (even 124+ octane ELF) will have zero effect on performance.
as for leaded, I dont even think about it as almost all race organisations (where is live anyway) have banned it.

[queen of spodes]

Why do you think you need race fuel?

This is a new/old bike.  Previous owner sold with a half a tank of race gas, which I rode out & bike ran smooth as silk.   He is a mechanic and had it jetted spot on.

When I drained the last little out of the tank/carb and switched to my preferred oil (supertechniplate) and 93 pump gas, the bike immediately started pinging on hard acceleration. 

[msmola2002]

My kx is jetted nicely for race fuel - and jeram, for $2.20 aud a litre, (last I paid was 8.80 a gal) it is worth it to not get any of that ethanol laced pump crap - I'd rather not deal with that, and come winter have to deal with fuel stabilisers when the temp drops below freezing and all that jazz. It runs right on this stuff, I'm not screwing with it

I am just running sunoco standard - 110 (R+M)/2 IF the thing is not tweaked far beyond stock, something cheap like the standard would be the go.

Where are you located?

[MPFD]

One thing about it, race fuel is made in smaller batches and the quality control is better. I like to use it in the summer and when I go to ride dunes. It really cuts down on spark knock in high temps.H

[Jeram]

I go out of my way to add extra ethanol to my fuel. 40% ethanol, 60% 100 octane (RON)
I beleive the approx (american) octane rating of my mixture would be around 95-98 plus the added cooling benefits which makes it  great for resisting detonation.

anyhow, back on track
IMO your bike is pinging/detonating most likely because its jetted for race fuel, not 93.
so decide what you want to do; keep running race gas with stock jetting or go to 93 and rejet  your bike.
but if the mechanic has modified the motor, it may infact NEED the race fuel

[queen of spodes]

It felt snappier with the race gas, so I'll probably go with that for a few months.  If I can't burn through 5 gallons in six months I'll just rejet for 93.

[KDXGarage]

Get an oxgenated gasoline for more power.

[motoxr377]

Get an oxgenated gasoline for more power.

Renegade SX2. I'm looking forward to trying it. Running a nicer gas is a good idea the last few years especially in foopers, mainly due to the ethanol blends here in the states.

[coblefutch]

My yz with high compression head mods loves 100LL from the local airport. At 5.68 a gal so does my wallet..
It sound like a coffee grinder on pump gas.

[MPFD]

For me it's not about making more power, it's about better controlled ignition. Pump gas is not always consistent enough for my taste.

[riffraff]

I run 100LL in all my bikes, I get it for free 

[captmoto]

I run avgas too mostly to get away from stupid Cali pump gas and all the additives. My CR250 starts first kick and my YZ465 is 2-3 kicks. Ithink it's mostly because the carbs stay way cleaner with no oil/gas separation. My YZ was a nightmare on pump gas.

[conbread]

i run my bike on VP113 oxgenated fuel.. its about 8.50 a gallon and i run the maxima super K at 32;1 and the plug is a perfect tan color.. Its way cheaper thana piston...