Running great but frying pistons!

[Oring]

That just goes to show you they always run good before they go bang!
So much for the paddle tyre in the dunes!
Cooked the piston pretty quick!
Last piston was breaking up on the inlet side.
This piston had the same pattern but the exhaust side was fried down to the ring. Bugger! (didn't the quad guys love that)
When checking the plug this thing looks great! mocha brown!
I must not be giving this thing enough throttle!
Any ideas on making it last longer, ie up a jet size etc?
Maybe piston choice?
Bike is running great when going, feels real crisp! Pings abit when running flat.
:
On the subject of paddles! wow that made my bike hammer,
reminded me of the yz 426 in the sand. Front end up everywhere.
Starting to think that 2 strokes and I do not mix
:
Help me out guys I've gotta get this to run more reliably!
Don't want to go to the 4strokes! Can see a 525 EXC or 450 YZ on the horizon!
YZ 250 03, 14/50 running silklene at 32/1 premium fuel
Pro circuit pipe and muffler.
Footnote: I'm really starting to hate Quads!

[Aus_Rider_22]

I think your bike is definetly jetted to lean!

Richen up the main (this is where you mainly ride in desert,WFO) a few sizes.

Has your bike got any engine modifications?? Porting, shaving etc?

[Oring]

No not yet it has a standard barrel and piston.
Used a Yamaha piston last piston.

[Thumprding]

No doubt richen that puppy up. It should not ping. Plus add in sand riding with a paddle. You have some serious load on that motor and use alot of throttle.

I would start with lowering the clip one. If that does not do it. I would put the clip in the middle position and go to the next larger main jet. That will basically richen the entire mixture from about 1/4 throttle to full throttle.

[audacity]

make sure you use leaded fuel for your plug chop!...WOT in top gear for 1-2 miles on fresh plug...DO NOT IDLE after.