stroker jetting

[k4f5x0r]

my friend just cracked his piston for a 2nd time(he thinks the piston is cracked atleast). We think its because he is running lean. his quad does not pop or anything but the piston barely has anytime on it and has no reason to crack this early. so im asking for some jetting help
this is for a trx450r electric start. an 06

he has
511cc stroker +3 mm stroker(balanced)
13:1 piston(wiseco)
sparks full pipe
K&N intake no lid
he is goin to get a coolerburning spark plug
he is also on a stock carb (06)

were on long island so we are at sea level and we ride motocross.

Any help is appreciated. :)

[k4f5x0r]

anyone guys? just need an idea on where to start. for the pilot and the main jet aswell. :)

[pro-rider46]

try like a 180 main, middle position on a aftermarket needle, 45 pilot, 55 leak jet. that should get you guys close. make sure he warms it up before riding it at all.

[k265r]

you should run half race gas and see what happens.

[k4f5x0r]

i forgot to mention he runs VP high octane mix with 93.

i think he hasthe hrc needle in right now because he's too damn lazy to jet :grr:

[hendershot106]

i ran a stroker crank/ je 13.5 piston/sparks cam/sparks exhaust/uni filter last half of 2007

i ran between 185-195 mainjet
hrc needle on 4th clip groove
boyesen quickshot
stock pilot
2.5-3 turns on fuel screw depending on track elevation.

[k4f5x0r]

we figured out why it kept spiderweb cracking pistons... he needs variable ignition timing. he was basically having explosions non stop whenever he revved over 1000 RPMs. so he's gunna get a new piston ignition box and a rev box.

it actually wasnt his jetting. his jetting is actually slightly rich since his sparkplug is blackish.

Thanks anyway though!

[jjm400ex]

umm ok