416 or 426

[chevy400racer]

hello i am deciding on wheather or not to boar my 400ex out to a 416 or 426... all right now i have a yoshimura slip-on and im definatly buying a header, but am having trouble deciding. i ride woods, tracks, drag, and road ride. cost isn't really a concern but i dont wanna put more money in a motor i just rebuilt that blows up.... any suggestions are apppricated.

[underpowered]

search. this topic has been beaten to death on here. search here or the 400ex forum, all kinds of info and opinions on this.


in general, they are both about the same as far as reliability goes, and similar power wise. the main thing is life. with a 416, once it wears out you can go to the 426. if you to a 426 you are on you last bore on the stock sleeve, or you can resleeve and start at a 426 then go to a 440 when it needs rebuilt.

it is all what you want to do, and how you want to do it. IMHO i would do a 416, that leaves you one bore on your stock sleeve left, but thats just me.

[chevy400racer]

if you don;t mind how much did it cost you and how long have you had your boar, on your 2000 400ex.

[GPracer2500]

I'd also go 416. The 426 isn't a bad choice, but when you weight out the pluses and minuses of each size, the 416 just looks better. IMO

[underpowered]

been together since oct of 03, so over 3 years now.

bought it the way with the bore, but just freshened it up last summer.

Piston:$150
Bore: $49 (varies alot depending on who does it
cam:$120
gaskets:$30


all i did this past summer was replace the piston, the bore was well within spec, only had about .5 degree of taper from top to bottom, so i kept the 426 bore. been on the same bore since 03. all i have to say is proper maintenance works wonders on longevity.

[atb7346]

Go to whoever is going to bore your cylinder and see if they have a 400ex cylinder laying around or just print out the picture in the manual and have him show you how far the bore go's. The 426 is almost bored over into your stud bolts and the 440 is right next to your stud bolts. I would go with the 416. Because like the guy said before, you can go to a 426 without a re-sleeve. I just made mine a 416 and it runs great. the only thing I screwed up on is replacing the cam chain. It slaps a little now when you bog the motor down. You might as well replace it while you have the engine broke down.

[proff x]

i bored my buddys out to a 426 and there where no problems just loads of power. the cam chain is a very good thing to replace while ur in their there is a company that makes a double roller id lookinto the forsure if i was you id say 426 it was under 400 to bore it out me and my friends did it in 3 days. the decompreesor gave us grieve. the 426 was able to keep up with my un mooded 450r and its better on the bottom end vs the 440 and the 416. it pulls hard and is a very potent quad to race. Id go 426