how much does it cost to make a 400ex a 440ex

[Manny55]

I have a 400ex and i want more power in it. I was wondering what the total cost of a 440 big bore would cost as far as jetting, 440 kit, the labor/bore job and everything else i might need does anyone know how much this cost.

[Bill X_R]

Not real sure, but I'd bet you could sell your 400ex then add the cash for the upgrade ... the total wouldnt be to far away from the cost of a new 450r!? Guess it all depends on what your bike would bring. Think you could get 4g's out of you 400ex? If so...seems like a no brainer to me!

[Manny55]

thats what im think selling it for 4000 grand and getting a 450r or and YFZ450 or all just make it a 440ex not sure yet.

[TravEX]

it can be done for $600 to $1500 depending on what all you choose to do

a buddy of mine made his a 440 for $800 with JE piston kit, Curtis Sparks Rev Box, pipe, and silencer. he noticed a HUGE gain, he mainly drag races, and has SMOKED piped and jetted Shee's, Raptors, Predator's, and a hopped up DS650.

[350Xccelerator]

yea i seen a 440ex a while ago, and holy crap was it fast! i asked the guy what he had on it he said he had a 440 kit, bigger carb, jets, filter, White bros r4 pipe, and it had 18in. fast trekkers, that thing was awesome!

[200xer]

you'll have to be very lucky to get 4k out of a 400ex. about 3k to 3500 is the going rate now.

[YTZ250#1]

According to TC racing,most 440 kits are only 430 to 435cc.When I looked in to doing mine he said it is cheeper and you get better results by just boring it to a 425.Why pay to have it resleeved when you only get about 5cc more than a plain old bore job.do a bore job,high comp. piston
and a nice cam,k&n power kit,and a nice pipe and you would be good to go.Keep in mind you can mod the stock head pipe and save some cash.
Just weld the pipe to the flange on the out side,and grind the welds off the inside.That opens the pipe up for better flow,and is a big improvment with a slip on silencer.Good luck with your quad,and if you find mine there is still a cash reward for it.

[smokinp]

I was reading in dirtwheels that you can get a 460 kit for the 400ex