motor help

[adrenilinjunki]

i need help i have a 2001 banshee that has been mildly ported its bored 50 over the timeings advanced 4degrees, toomy t5s toomy jets k&n pod filters duncan reeds and a boost bottle. it keeps blowing pistons at first it was the were just wore out so i replaced them with a set of numara pistons witch are crap for any one who wants to know i blew one to peices with less than 2hrs on the rebuild. next i bored it out to the next size to to some scratching of the cylinder, and put in a set of weisco pistons ran it less than an hour seemed fine then all of the suden it just died and it wouldnt kick over. i took apart and found another blown piston this time on the oppisit cylinder there weisco so i couldnt blame it on crappy knock offs. i checked the water pump and its getting coolant through the motor, the jeting was right on and there was plenty of oil in the mix i wansnt romping on it hard becuse i was just breaking it in so im at a loss im thinking something might be up with the crank or cylinders the rods, crank and berings all seemed fine when i tore the motor down so any ideas where to check would be greatly apreciated

[lowriderb]

are the pistons coming apart or are they melting in the center of the crown of the piston?

 

if they are coming apart then you may have a crank problem.. if they are melting on the crown first then it is probably a crank seal if not the jetting..

[FasterThanU90]

yea need more info on piston condition it could be a number of things

[adrenilinjunki]

the pistons are comeing apart the tops look fine but from the rist pin down is in a hundred peices

[FasterThanU90]

if the skirt is shattering the cylinder is probly out of round or has a good amount of taper u can get a dial bore gage and a mic if u can read them, or take it to a shop