my r blew up

[bens250ex]

well i was riding today and i was messin with the jetting and then i found the right one so i rode about 30 mins then a couple hours later i go and ride in my yard for about 10 mins and then bam it just shuts off and i hear this clunk i was like **** i knew what happind i tried to kick it over to see if it moved but it wouldnt so i pushed it in the garage and started tearin it apart and i got the cylinder off and the piston was like done for had gashes and missin parts of the rings...well i tried to turn it over but it still wouldnt so i pulled the motor took the stator cover off and got the nut that holds the stator on to back off and then i went to tighten it and it stated to move freely again....it turn smooth now and all but i still need to flush the case to get all the stuff out but my question is i gotta get new piston and rings and all but it was bored to a 262 which bore size is that and isnt there only one more bore left? if there is i think im going to go ahead and bore it to the next level to make it smooth...what size is after 262? and how much will it run to get bored? also what is a good brand of pistons i wont a really trustable company so if anyone has any let me know thanks

[Tom TRX250R]

I believe the next bore is .80 over which is a 265. You can run up to .140 bore if you run an 86 piston. Just have the machine shop bore it .10 over, that should be plenty unless it really gouged the cylinder. To bore the cylinder should only run you about $40. I have always ran Weisco Prolites with good success. Just make sure to break it in really good and you'll have a reliable set up. Also make sure you get jetting good, I would run a little on the rich side for breaking in to be on the safe side.

[Dave83]

.080 over is the bore for a 261-62 next would be .100 over (68.5mm) for a 265 cc cylinder.