Build a 250 Mod?

[TEXWS6]

I have toying with the idea of building my daughter a 250 (4stroke) based mod for awhile now. She is 12 years old, 5' and weighs 85lbs in gear. I am just ready to get her off these mini's, as she is currently racing a DC Apex, and a TRX125. We race TQRA and she would be racing this 250mod in the women's 450 class. Questions:

Will a smaller bike with a 250 motor run with the 450?

I found a smoking deal on a shortened 400ex frame, does the DC or JB pose any advantages when going this route?

What powerplant is the recommended one(CR, YZ, RM)? I have found a good deal on a 2004 YZ250F.

Any other comments and/or suggestions would be greatly appreciated.


Thanks,


Kelly

[ds450racer]

i used to have a yfz 450 with a yzf 250 engine in. It would keep up on technical tracks but if you got one a bit more of a wide open track it would struggle to keep up the the fo fiddys. Great bike though and i would reccomend getting a wr250 engine for it.
It wont let me post pics up but if you pm me your email address ill be happy to email you some pics across of it.

[woodsracer144]

Originally posted by ds450racer
i used to have a yfz 450 with a yzf 250 engine in. It would keep up on technical tracks but if you got one a bit more of a wide open track it would struggle to keep up the the fo fiddys. Great bike though and i would reccomend getting a wr250 engine for it.
It wont let me post pics up but if you pm me your email address ill be happy to email you some pics across of it.

linke he said the 250 would have a hard time on a wide open track... but dungey was on the RMZ250 racing in the 450 for a little bit and doving VERY well... i got a buddy taht ways racing a crf250f and he was beating 450s...

[kincaid6pack]

best junior hybrid you can build is yz or honda 250f like iv done, with yamaha my 12 year rides and loves it. with little motor mods it will run with 450 beginers.

[kincaid6pack]

best junior hybrid you can build is yz or honda 250f like iv done, with yamaha blaster my 12 year rides and loves it. with little motor mods it will run with 450 beginers.

[400ex4ever]

I would have to agree with kincaid6pack. I went with the Honda 250F for two reasons. No external oil tank (cleaner build) and it's a Honda. To date mine only hase the modified exhaust and it is really fast. My son is adjusting quickly but it is still a hand full switching from the 2 stroke powerband. Here's a pick:

[woodsracer144]

is that a JP 90 geo chassis? or a 400ex or what? thanks

[400ex4ever]

Originally posted by woodsracer144
is that a JP 90 geo chassis? or a 400ex or what? thanks

Not to sure what a JP 90 chassis is but mine is a JB Mod frame. The one he uses for his 150 builds.

[kincaid6pack]

hey 400ex4ever, i talked to you for a min at the glen helen nationals this month, my son rides the white yamaha 85 cobra. your son looked really good on that new bike, he's gonna be hard to stop when he really gets a handle on that thing, his starts are great, that thing really hooks up. hope our boys get to battle soon. maybe see ya at the itp series

[GOTFEAR]

i
I just did one for a customer a JB 90 frame mod with a crf250 motor and pip its a sweet bike and you can work on motor in frame