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Technical / Re: Do I need race fuel?
« on: October 06, 2011, 12:39:32 PM »I have a 2006 YZ250 and have been riding it for a couple months. It seems to run well, but I am coming from 3 previous 4 stroke bikes so I am not well versed in 2 stroke performance.>:-D yes I have seen 2 bikes blow up on pump gas because of the detonation issues one 04 cr250 and a kx125 so def make the investment now rather than late
Two other riders that I know that have quite a bit more knowledge than me on 2 strokes say that they went through pistons within 5 hours on their YZ250's because they weren't running high enough octane fuel (race fuel). They both said they ran premium but recommended that if I continue to ride/race my YZ that I run race fuel, or at a minimum blend it with premium gasoline.
This seems like a huge distraction for me as race fuel isn't immediately available, not to mention expensive.
Maybe some background is helpful; I ride 2 -3 days a week all MX tracks. I race monthly in C and Vet classes, so nothing too fast, but still competitive. I am mechanically inclined, I rebuilt the top ends' of my 4 strokes in the past and am not afraid of rebuilding my 2 stroke now.
The bike runs well, the spark plug tells me the jetting is reasonable. I currently use Sunoco 93 octane with 32:1 S2 oil. I haven't pulled the head to look at the piston, but plan on doing that in the near future. I do however notice some odd sounds from my YZ but because I am not used to 2 strokes they may be normal. I cannot tell if it is detonation or just "2 stroke rattle".
Any advice?