250x run with a 400ex?

[fastkid400]

I have a 250x and was wonderin if u put a high comp piston, cam, 400ex carb, pipe, just most of that kind of stuff, if it wood run with a 400ex?

[roostin_dale]

get a curtis sparks motor kit..you will have no prob. beating 400ex's

[fastkid400]

where at, is it alot bigger?

[wvspeedfreak]

The 250x is a great 4 wheeler but with the mods you listed it won't touch a stock 400ex.

[atvracr350]

Yea sorry dude but you might as well buy a 400ex for the price of the stuff you will have to do to that 250 to make it run even close to the 400. I mean think about it, older engine at 250cc's or a newer engine at 400cc's its common sense. I raced a 250x on my 400ex with him having a pipe, airfilter, jetted right and holeshots and I beat him by about 20 bike lengths. not even a close race.

[CowsBitePeople]

Or u can put a 350x motor in that beast:macho

[westcoastmxer]

hey man i run w/400ex's all the time at the tracks and the only motor mod is a tc racing exhaust wich gave me like 3 times the power of my fmf and a uni filter w/no airbox lid..i highly suggest gettin a tc racing exhaust or curtis sparks.(i prefer tc tho)im also gettin a web cam and maybe a 330 kit..good luck dude

[roostin_dale]

Originally posted by westcoastmxer
hey man i run w/400ex's all the time at the tracks and the only motor mod is a tc racing exhaust wich gave me like 3 times the power of my fmf and a uni filter w/no airbox lid..i highly suggest gettin a tc racing exhaust or curtis sparks.(i prefer tc tho)im also gettin a web cam and maybe a 330 kit..good luck dude

im sorry to make a rude comment but you also said you could beat custom crf quads on your basically stock 300ex..

[RMX500]

Originally posted by roostin_dale
im sorry to make a rude comment but you also said you could beat custom crf quads on your basically stock 300ex..

I second that. :D

[westcoastmxer]

hey dude i didnt say that i said i beat this stock crf450 at the track cuzz it had a sucky rider on it ino i couldnt beat one w/a good rider

[quadmxracer]

Has anyone on here seen a 250X bottom end with a 350X top end on it? I have and the guy said because the 250 has a good lower end and the 350 has an excellent topend. He said its just a pisser to start. But he said its worth it. Just wondering if anywone else has heard of this setup?

[Xowner]

why not use the 300ex bottom end ? or use the 350X bottom end 6 gears and a kicker and bottom end that was made for it you might break a rod or something with a 100 more cc then the 250X bottom end was makde for

[fastkid400]

Yesterday, i was racing my dad, him on 400ex and me on 250x. With my 400ex carb and cobra piece of shat exhaust, i kept up with him until third gear, then he started to pull away, but man im inpressed:D

[wheeltrax]

I know my 250x isnt too bad, but there isnt any way i can hang with a stock 400ex. I was thinking about getting an engine kit, but then lookin at the 1000 that id be spending, i got to thinking for another 500-800 bucks, i could have a 400ex, and in the end that would be better to stick money into. So come fall or late summer im looking to get a 400ex

[wilkin250r]

It's entirely possible to build a 250X to beat a 400EX. One method is to put the 350X engine in. The 350X will hang, but you'd still need some mods to make it beat the 400EX.

Even without the 350X engine, you can build a 250X to beat a 400EX, but a simple high-comp piston and camshaft isn't going to do it. You'll need a stroker crank, a HUGE bore, high-compression, camshaft, oversized valves, port and flow, as well as a carb and exhaust to compliment the entire kit. And that's just the motor, now you need suspension to handle all that extra power.

Basically, the point is that while yes, it is possible, it's not very practical. Because after all that, you can't go any further. You really are better of taking all that money, and just buying a 400EX to start with.

[TRX300X]

My 250X will smoke 400's all day long and best of all it's for sale :D.

[roostin_dale]

got pics, price, mods? or a link to the forsale section or sumthin?