416, 426, 440??

[lonestar13r]

hello all. right now my 400ex is still the stock bore and piston , i'm plaining to upgrade next winter to somthing a bit more radical, but i'm not sure what to go with yet, money wise the 440 seamed decent, but the 426 seams to be a winner in top end. i have never really herd much about the 416 .I'm rebuilding the bike for motocross . can some one give me some pros and cons of either the 416, 426 or 440 kits ?? how much money did you do it all for?? what did you do for a carb ?? thanks alot !!!! -Ethan

[400ex28]

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[DaleJrFan]

i have had this debate for a while now. i want to upgrade but you have to weigh you options. i would stay away from the 440 for motorcross. you have to bore the stock sleeve so thin that it can crack. the 426 is good but there is a lot of other stuff you coud do to make it better like port and polish and bigger carb. I think for the money, the 416 revs higher and you still have reliability with it. if something goes wrong, you can still bore and what ever bore you decide to go with, dont get talked into hardened rockers and springs, i have two buddies to it, one with a 426 and one with a 440 and both bikes were constantly overheating.

[cals400ex]

if i had to do it all over again, i would get a huge bore. i do NOT want a stroker. to many people get theirs done and they are slower for drag racing. for woods or low end power, they can't be beat. with the larger bores, like 440 and larger, you don't have to shift nearly as much and it has a lot of low end power, even with a stage 3 hotcam for example. i have a 426. a 426 is actually right over the limits for the stock sleeve. most just reuse the stock one but i wouldn't. for a 440, you don't have a choice. you need a new sleeve. if reliability is more of a concern, i would build a nice stock bore to a 416 and get a cam that suites your riding style and a good FULL exhaust system.

[smith_400ex_213]

go with the 426 it revs alot fast than the 440 ...more leliable...my buddies 426 has jsut about every motor mod u can do wiht it dont over heat....one day we went race and he is in the b class and did 5 laps and won..and my other buddy raced 5 laps in the A class the exact race after the b class...and won that one too... and still pullking strong

[TC426EX]

^^

I dont know man, youre gonna get a certain level of fading if you ride a built EX Wide open for a long period of time. I definitely can sense some slight fading on my 426 after an extended period of time at practice especially since its air cooled and all. I even got the FST auxillary cooler, Quadtech scoop hood, side air scoops, run synthetic oil, went to a cooler plug, run straight race gas, and it still will fade a bit after an extended period of time...

[frogburner]

Originally posted by smith_400ex_213
go with the 426 it revs alot fast than the 440 ...more leliable...my buddies 426 has jsut about every motor mod u can do wiht it dont over heat....one day we went race and he is in the b class and did 5 laps and won..and my other buddy raced 5 laps in the A class the exact race after the b class...and won that one too... and still pullking strong

Reving is not everything. I have a buddy with a 426, I have a 440. His may rap a little quicker, but the monster torque that the 440 builds is impressive, I can slap gears extremley early and pull through them without a problem, I would go 440 anyday over 426. I rode at Turkey bay all last weekend, and my 440 ran warm, but never had a problem with over heating. If you build it right, take your time, and do your homework, you would find that 440's are very impressive and reliable.. I just dont like people getting bad images of big motors..

[lonestar13r]

Yes, i'v herd that the 426 was more noted for fast reving. at the local quad shop here, they had a 426 for sale about a mounth ago (should of bought it !:blah: ) but any how, the dude was telling me that you almost have to go with an after market oil bladder. other then that, i didn't really look closley at the bike. I also new about the new sleeve for the 440 kits. the 440 sounds like less work and money, but the 426 seams like it rips alittle harder ( for MX any ways). can some one tell me alittle about what other mods came with doing the 426 engine?? such as oil bladders, Carb, ect ect. I allready have a Full Yosh. E-lll exhust on it. thanks alot guys ! ....and p.s....why couldn't honda make the 400ex's liquid cooled ?!?!? ha' later
-Ethan

[jhvmat]

I build motors I have 3 426 in GNCC they are very reliable. I do recommend port and polish, stage 1 cam, depending on how old motor new timing chain and guides, valve job and seals. we run Klotz 113 in all the engines makes them run cooler 93 octane will overheat the engine. We also run a oil additive made in Fla. All the 2 wheeler guys use it but not many quads yet. I have specs on the additive it will lower your temp 60 degrees. let me know if you need any help. I can e-mail you the spec sheet. pm me and I will tell more about it if you want to know
J V.

[lonestar13r]

I'll PM you asap JV !! thanks for the help, the motor i'm thinking of doing is an 01' , i think you can work a 450r heavyer timing chain in them?? i'd have to look into that some more. as for the additive running 60* colder, thats a big plus !!! i think i am going to go with the 426 now thoe... Port and Pollishing isn't to expensive i don't think (?) for what it is, i would deffently get that done. now i'm trying to come up with a list of what i need and need done, i don't have much yet... piston (not sure what size it is exactly) rings ,,, not sure if its nessesary or not, but i'd buy a heavyer Rod ,, i'm going to look into what kind of work it takes to make a stroker and what bennifits it gives.. basicly i'm getting ready to do lots and lots of home work befor i touch it at all. thanks for the help guys
Jv like i said, i'll PM you next time i see your on , later
-Ethan