a 450 is nice but i would go with a 400 450 will probly need alot of head and valve work if u run it hard plus a 400 will save u money.....

 

I agree that it's not worth putting money into the 250ex. My brother already spent 1000 on extras for his, and he's wishing he had just saved the money for a 400 instead. In my opinion the biggest limiting factor is the shaft drive. It's maintainance free and super reliable, but the gears are too low and you can't get any more top speed out of it no matter what you do to the engine.

Running WOT won't hurt the engine. I've held both my recon and my brother's 250ex wide open for miles at a time, and it never did any damage. My recon got rode wide open A LOT, and it went 5 years berfore the first rebuild. My brother's 250ex is still on the original rebuild, with no signs of power loss or smoking.

 

Riding wot with a big bore is nott good for ur engine...Riding wot with a stock moter is nott very good either i mean u run the chance of over heating and seizing up but with a big bore u moter over heats faster so ur just runing in to a more chance that ur gona over heat nd seize up ur moter..........

 

The big bore on a 250ex isn't a very big one. And when you're running wide open for extended periods of time you're moving fast, which means more air is moving over the engine, and it's cooling off more.

Just yesterday I went for a wide open run down the road on my bro's 250 because my warrior isn't back together yet. I was running wide open throttle for about 5 minutes straight except for a couple sharp turns, and when I got back home the motor was cooler than when it gets when trail riding, beause when you're blasting down the road at 55 mph you have a LOT more cooling then when you're going 15 around a trail.

Sure, the higher rpm's will put a little more wear and tear on the parts, but nothing has worn out yet. This engine is almost too weak to really do any harm to itself to be honest, that's they way honda designed it, that's how they design most of their quads, which is why they are so reliable.

 

i have a 250ex and ive wanted more power at times, ive added a pipe and jet kit and filter, this improves it alot , but im still wanting more power . so ive decided to get a 400ex. theres no point in getting a big bore for a 250ex. its kinda pont less. its shaft drive and auto clutch and the engines really not made to be bored out on this quad

 

Exactly. Once the pipe, filter, and jet kit aren't enough there's no sense in spending big $$$ on motor work. With a big bore kit, cam, and a ported head on a 250ex it still wouldn't be close to competing with a bone stock 400ex.

 

IM getting ready to get a new 4 wheeler something aroutd a 400 can someone tell me wut i shoud get????

 

How bout some more info? Like what kind of riding you do, what your size/weight/age is, and how much you're looking to spend.

 

i have a 250ex and i admit it aint worth fixin it up to race about the clutch thing my friend has a lakota (kawasaki) and he went to the dealer they have all the parts i think it was gonna be about 300 including labor but it will be a little diff. and thats if they even have the parts so the best place to look is probably the dealership but if you could find one somewhere else just make sure it has everything and if you do tell me where you get it and how much

 

i've also got a 250ex unfortunetly i don't have a big budget so i can't buy alot of upgrades for it even if it was worth it so instead of buying a pipe for it i took out the spark arrestor(or something that slowed the air flow) and i got much more torque