blown engine

[ATC250Rider]

ok guys, bad things happened this past sunday:mad: . my 250r, blew up. heres the ? ok i had already bored my trike as far as i could go, and yes i am the one who was asking about the porting. see i am in college and i had a blown head gasket, so i ordered a new one and had my little brother (who yes he knows what he was doing) instal a new gasket. well he forgot to fill the radiator back up, and it sliped my mind becase i was excited to get back on it. so my ride got really hot, needles to say. so now i am looking for what i have seen on other rides. i beleive they call it a 340 power valve cylinder, i am low on money right now up until the month of june. but can anybody get me more info on this topic, and or were i could get one or the info on it?

thanks ATC250Rider
Yeehaw, i get to make it bigger:)

[Wickedfinger]

Let me ask you a question .... did you overbore your stock cylinder past .80 because you thought it would give you more power, like a Thumper or was it just through progressive rebuilds and next size boring?.

[Oldshell4481]

its not the size of the bore its the compression you get that gives you the power isnt that what sleeves are for?? when you need to get your cylinder back to size. im not sure thats just what i was guessing, ive never had experience with boring and stuff

[ATC250Rider]

well when i received the trike it was blown up, so i was going to rebuild it, well i got all the parts and was puttinmg it back together when a ring jumped off the piston half way and gouged the cylinder, so i had it bored to the next size and found out that wiseco don't make a 250r piston and 1.75 so i ended up going to 2.00 over. i had planned to have it ported and polished, and from what the other guys said have the head milled too. i have also been looking for a dyno too but all the shop round here tell me to go buy a four wheeler