03 Kx-250 Pinging Problem

[SHWANTZ34]

HI ! I have some pinging problem with my 03 KX-250. The bike is completely stock, and i'm pretty sure that i have all the stock original jetting. I just bought it a few weeks ago, and everathing , including the tire were original, and praticly new. The guys was using it to train is peewee kids. Ok now for my pining problem.i use Esso Supreme 91 Octane mix with motul 800 mixe32:1 , Same gas that i used in my other bike ( Cr-250 01 ) . My Cr works very good with that fuel. I try to close the mixture screw half a turn to 1 turn it help a bit , but its not perfect.I would like to know if somebody with the same bike have had this problem , and what is the receipe to meke it work ok.I would like to use something as standard as possible , if possible no race fuel or a mix of it with super pump fuel. I'm no millionaire, and used the bike on racetrack but only for fun.If you have any sugestion please let me know.
What is the minimum Octane riquirement, any jetting indication, like delivered to lean from factory etc.. The jetting seems to be ok the plug have a good light brown color.

P.S I' M new with 2 stroke bike, help me if you can.
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[oldfrt613]

If turning in the air screw helped, you may want to try the next size larger pilot jet. Since it's a 250 and you don't really ride it hard, you could try mixing at 40:1 also. In either case you will be richening the mixture. With the pilot jet, you will only be making an adustment on lower throttle settings. Changing to 40:1 will change it at all throttle settings. If none of that helps - you may have to improve the fuel. Try another name brand premium fuel - preferably one which doesn't contain alchohol. We have good luck with Amoco Ultimate. Next you may have to try a good octane booster or perhaps 25% race fuel to 75% premium to see if that helps. If it's stock one of those things should fix it.

 

[ellandoh]

oldfrt, i was looking for octane boost for the truck a few weeks ago, the one i found had a big warning on it not to use in a 2 stroke motor. are there some that are safe for 2's ??

 

[oldfrt613]

Yep - you just have to check - I don't recall the brands though - I'm sure Rich would have a suggestion. I finally came to the realization that it realy doesn't cost that much for race fuel if you shop around in the grand scheme of things, and it pays in spades in throttle response an jetting consistancy, so I haven't messed with those products for years.