I'm wondering if anyone knows how far a 250 can safely be bored. I'm looking for what mm piston the std bore is and what mm piston you can go to. I'm planning to build a drag bike and trying to get my facts straight before I start. Thanks

 

the std is 72mm. the biggest piston wiseco offers is a 74mm which is .080 over. i wouldnt reccomend boring it to the biggest size right away cuz if you fry the cylinder you wont have anything else left to bore which will leave you with a useless cylinder. if you absolutely want to bore it i wouldnt do anything over .040 with is 73mm.n then you will have extra to bore later. and boring wont give you much of a power gain. check out rick ritter or hpd's site for engine kits. hope i helped.

 

The reason I ask is because I found a site (I can't remember exactly where) that sold a big bore kit for a 400 and I didn't know if there was anything like that offered for a 250. I am also assuming that the big bore for the 400 is just an over bore, unless it is a completely new jug, because I can't see how a 400 jug could be resleeved. I have a 03 400 and it looks like it is poured around the sleeve somehow.

 

you need to talk to Az Bad boyzz they do alot with the 250 motor has stroker kits an reedcage convertions.http://pub8.bravenet.com/forum/show....rnum=612682403 this is the web site can leave question there. He has really good stuff an also drag races

 

Exactly!!! If you are seriously wanting to set up a drag 250 than you need to talk to Dennis. I just got my 12mm 250 back from Dennis and raced a stock banshee a just walked away from it. I have the 4" swingarm on it and can't even keep the front end down. Thinking about changing my rear sprocket to a 34. Right now i am set up at 13 36.

 

Just a couple more questions, where are az bad located and what is involved with having them do the work? Do I send my motor to them and they take care of it? This one is for 1fast, If you don't mind could you give me an idea of what it cost for the 12mm. I assume that you worked the clutching over as well what did you do to yours. Thanks for the help.

 

Located in Phoenix, Arizona....That is why he is called AZ BAD BOYZ....You just send him the motor or whatever he tells you to send. He is good to work with....To do all the motor work is around $1600....I put his race pipe on and you will need a 300 cylinder and a 34 mm carb or 35 kehin..You will need to call him for a price quote.....Worth every penny...Everybody says to me why spend the money on a 250 when you can just get a 400. First of all if you already have a 250 and you want more power then you will spen the same money as if you were to go and buy a 400 cause usually you will loose money when you sell the 250. I have three 400s and I would do this over in a heart beat.

 

dennis's race pipe will work on teh 300 jug? how does that thing run? i want it lol. right now im thinkin about jsut goin for the reed mod and then maybe later cell the jug and piston and go get a 300 jug and have it reed modded and stroked and bored. which route would u go. i want good performance and i need to be able to hang with shees adn warriors(i know i would kill these with the reed mod). and i could always go to the 7mm stroker with the stock jug.

 

Just all depends on how fast you want to go. I like them both. Me personally, I love the 12

 

do u have any pics of your bikes? could u give a quick rundown of the mods that u have on your 7mm? thanks, scott