450r carb for 400ex

[GB400EX]

I have a 2005 400ex and im looking into doing a upgrade for the carburator and was wondering peoples opinions.. What year 450r carb would i need if i went with that?

[Sanddraging28]

i use a carb off a 04-05 trx-450r. i have done a bunch of these. you also need the throttle cable and fuel line off the 450. let me know what else is done to your bike and i can get you in the ballpark with your jetting......a 450 carb makes an unbelievable difference with power and throttle response. if you need more help let me know

[GB400EX]

so far i just have a stage 1 hot cam, full header and exhaust and jetted. I noticed your ported and polished, did you notice a big difference with that??

[Sanddraging28]

the port and polish made a decent difference, i think the bigger valves made more of a difference. the quicker you get the air in and out the more power you can make.....with those mods i think you would love a 450 carb. once it is jetted right it is like riding an EFI quad. ebay is a good place to look for them, but dont pay more than about $150

[GB400EX]

I was thinking about doing either a 416 kit or a 426 kit what do you think?

[Sanddraging28]

both are good bikes if they are built right.. it really depends what kind of riding you do. i have a 416 and i am in the process of building a 426 for my brother..i have had 2 426's and both ran awesome, great power, the down side is that when it comes time to rebuild a 426 you have to get a new sleeve pressed in. with a 416 you still have a chance to go one more bore size on the stock sleeve. but you can get a 426 piston in a higher compression than 416. but with either one you should upgrade to a stage 2 hot cam, or maybe a mega-cycle cam but they are kinda pricey