RB head and gas..

Questions and Answers about the best carb and Head mods available for the KDX.
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frenche200
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RB head and gas..

Post by frenche200 »

Hello!
I bought there a few times a RB Head (not for competition gas) at a member of the forum (transaction very pleasant ) I have not still installed but I have a question:

Here in France we have different fuel:
-SP95 (95 RON, MON 85); : Unleaded petrol (lead is replaced by potassium), 95 octane (it seems me it is 5% ethanol)
-SP98 (98 RON, MON 87) unleaded fuel ( lead is replaced by potassium), octane 98
-SP95-E10 (95 RON, MON 85). : Unleaded 95 octane, 10% bioethanol

Currently, my bike ride to SP95 or SP 98, and I wonder if the fuel is compatible with this new head , and which is better?

Thank you :D
i'm French and I don't speak English very well, so, please, excuse me :)
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6 Riders
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Re: RB head and gas..

Post by 6 Riders »

SP 98, everytime, no matter what head you are running.
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SS109
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Re: RB head and gas..

Post by SS109 »

6 Riders wrote:SP 98, everytime, no matter what head you are running.
I agree.
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frenche200
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RB head and gas..

Post by frenche200 »

thank you guys! particular reason to prefer the SP98?
i'm French and I don't speak English very well, so, please, excuse me :)
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bufftester
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Re: RB head and gas..

Post by bufftester »

Highest octane and no ethanol is my guess. Supposedly Ethanol in fuel can be linked to reduced life in seals (specifically crank), although most seals are viton and not harmed by ethanol. Kind of the same argument as synthetic vs non-synthetic oil...
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C George
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Re: RB head and gas..

Post by C George »

6 Riders wrote:SP 98, everytime, no matter what head you are running.

+1 ,,, mostly because it's got no ethanol ,, terrible stuff for 2 strokes
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Re: RB head and gas..

Post by KDXGarage »

In the USA, we have RON+MON/2, so SP98 is 92.5 in the USA.
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SS109
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RB head and gas..

Post by SS109 »

I run the highest octane I can get (91 around here) because my bike just flat out runs better on it.
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scheckaet
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RB head and gas..

Post by scheckaet »

SS109 wrote:I run the highest octane I can get (91 around here) because my bike just flat out runs better on it.
+1 on that.
frenche200
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RB head and gas..

Post by frenche200 »

thank you for all your answers! last question: do you think I need to change jet to mount the new head?
i'm French and I don't speak English very well, so, please, excuse me :)
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diymirage
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Re: RB head and gas..

Post by diymirage »

yes, any change to engine or running conditions you should rejet
if you change what gas you use, rejet
if you change what oil you use, rejet
if you change your gear ratio, don't rejet, that has nothing to do with the engine :lol:
but if you change compression and squish band, rejet
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scheckaet
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RB head and gas..

Post by scheckaet »

check my sig for jetting how to. nothing expensive or complicated, just time and patience.
frenche200
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RB head and gas..

Post by frenche200 »

thank you Diymirage and Scheckaet! I thought about changing my pipe for an fmf so I'll put everything at the same time, to make adjustments only once .. thank you for everything! :grin:
i'm French and I don't speak English very well, so, please, excuse me :)
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