Upgrade to 440EX or stick with 416EX??

[ATVGurl]

I have to get motor work done on my 416EX anyway as it's blown at the moment...just curious to hear opinions on how much of a difference the 440 kit would make if I decided to 'upgrade'. Thanks in advance.

[bartlettracing]

dont go 440 .. you race xc and mudd .. the 440 wont realy give you more hp. but it will run hotter and unless you get the hd stud kit you will have head gasket trouble in the future ....

just run a 11:1 piston and a stage 2 cam ... and remove the choke from the stock carb .. this will give you plenty of hp for any xc race we go to ...

also replace the cam chain ... they tend to wear quickly ....


see you in fort dodge .... :D

[mxpimp2000]

if i were u id go with the 426 kit its soo much faster and real reliable to i had it plus stage 2 hotcam crf450 dirt bike carb. no air box lid HD cam chain it was super quick and had no problems with gaskets or studs if u go with a aftermarket cam dont let the engine idle i made that mistake b4 and cost me rocker arms and a new cam

[atvhonda-rider]

stick with the 416 for sure, 426 same amount of power jsut runs a lil more hotter and i like the reliabilty and flexibilty of the 416.

[burnthesnikle]

i haven't ridden a 416....but love my 440...stage 2...always ran strong...but yes do the head bolts...

[Dew2008]

Stay with the 416, more reliable in my opinion. If you want to go bigger go with the 426. I had a 440 and did not like it. It was really made to go fast, not good for trails. Piston just went out on me so I am going down to a 426. Just my $0.02

[r-exrider0003]

if i were you, id go with a 426. ive gotta 426 11:1 hc st II, 04 450r carb, port and polish, and its got plenty of power. never seems to over heat either, im going to install a spal fan soon i think. i cant really compare to a 440 or 416, as ive rode neither, but my 426 set up runs pretty stong.

[gcart2]

just get yourself a good motor builder and you will not have to worry about boring it over. with a Good motor builder you could easily get plenty of power without sacrificing your motors reliability.

[Cool Guy07400EX]

So then in what way is the 440 more powerful then the 416?

[burnthesnikle]

i have to get my motor back in a frame....440

and race a 416...because my 440 up against a 400....just kills it

and when i raced my cousins 450r i stayed right with him neck and neck...which made him a little upset

[REDRIDDER]

all ill say is i love my 426 it's in between the 440's power and the 416's acceleration in my opinion.

[Ruby Soho]

the 440 really doesnt have heat issues as long as you keep moving:p

[JOHNDOE83]

440s the way to go

[exrider272]

go 426... what i found out is that you dont get more power out of a 440 unless u have a bunch of motor work done... b/c ive owned 3 or 4 ,440s and they dont run anything like my 426.

[atvhonda-rider]

i always get deterbed when people say 440 or nothing... you realize how much more work and maintainence they are? with the cylinder wall that thin they over heat easier and when you can build a 416 with the same amount of power and MORE reliability than a 440, go 416 because if that blows.. you can go 426 then 440... start small on bores.. a 440 sounds more powerful, but its just a bigger displacement.. a 416 with a higher compression piston would mop a 440 with a lower compression.. your engine is all about the combination of parts and how well it breaths.. get a 416 with a port and polish with a carb and watch it scream, now when it comes to cams, a hotcam stg.2 i think is the best cuz its mid range power which is usually where you'll need your horses. BUT theres also a web race cam but you'd need to harden your rockers and get titanium valves and springs, but it'd breath and work well and be reliable with your port and polish. not knocking on hot cam at all because you can do the same with them as well. ALSO, get a good exhaust, a slip-on is senseless if you race due to the stock headers usually aren't built to breath as efficiently with a P&P and engine work etc. compression and air flow are everything, displacement just gives it a LIL bit bigger area to blow the mixture up on! (thats how i picture it :D )

[Cool Guy07400EX]

Originally posted by atvhonda-rider
i always get deterbed when people say 440 or nothing... you realize how much more work and maintainence they are? with the cylinder wall that thin they over heat easier and when you can build a 416 with the same amount of power and MORE reliability than a 440, go 416 because if that blows.. you can go 426 then 440... start small on bores.. a 440 sounds more powerful, but its just a bigger displacement.. a 416 with a higher compression piston would mop a 440 with a lower compression.. your engine is all about the combination of parts and how well it breaths.. get a 416 with a port and polish with a carb and watch it scream, now when it comes to cams, a hotcam stg.2 i think is the best cuz its mid range power which is usually where you'll need your horses. BUT theres also a web race cam but you'd need to harden your rockers and get titanium valves and springs, but it'd breath and work well and be reliable with your port and polish. not knocking on hot cam at all because you can do the same with them as well. ALSO, get a good exhaust, a slip-on is senseless if you race due to the stock headers usually aren't built to breath as efficiently with a P&P and engine work etc. compression and air flow are everything, displacement just gives it a LIL bit bigger area to blow the mixture up on! (thats how i picture it :D )

Well I've made my decision...416 it is!!

[CSR400EX]

Originally posted by atvhonda-rider
with the cylinder wall that thin they over heat easier
most 440 kits come with a thicker sleeve, and they dont overheat as bad as some people let them out to be. i owned one and used a stock exhaust, stage 1 cam, and a rev box and never had any issues of reliability or overheating. i also used the HD stud kit for insurance of head gaskets. performance wise, with the mods listed above, it ran a bike behind a stock 450R with a 13:1 piston.

[Ruby Soho]

the 440 really isnt as unreliable as people make it out to be.

it does get hot, but not THAT hot.

keep up on your maintenance and you will be FINE. mine is 1.5 years old now and shows no sign of wear what-so-ever.

my 11:1 (true 11:1) 440 with mods in signature was beating 450's of all kinds on straights at the mx track.

[madmartin]

i have the 440 kit and it runs excellent. can't say i know much about any of the others though. check out the gt thunder web site. look in the test bench section and you will find they ran tests on just about every variation of the ex that you can imagine. You can't argue with dyno results. I just ran an xc race last weekend and i have to say the bike performed great. no problems at all, and although it has all the work done to it (stg 2, ported head, exhaust, and carb) it did not give an inch to any 450 out there.

[300exkid123]

i had a 400ex with a 440 kit and never had any problems as long as the its moving over heating is not a problem and that motor would blow the doors of any 416 or 426

[JOHNDOE83]

absolutly...i agree...lol

[400ex28]

Originally posted by atvhonda-rider
i always get deterbed when people say 440 or nothing... you realize how much more work and maintainence they are? with the cylinder wall that thin they over heat easier and when you can build a 416 with the same amount of power and MORE reliability than a 440, go 416 because if that blows.. you can go 426 then 440... start small on bores.. a 440 sounds more powerful, but its just a bigger displacement.. a 416 with a higher compression piston would mop a 440 with a lower compression.. your engine is all about the combination of parts and how well it breaths.. get a 416 with a port and polish with a carb and watch it scream, now when it comes to cams, a hotcam stg.2 i think is the best cuz its mid range power which is usually where you'll need your horses. BUT theres also a web race cam but you'd need to harden your rockers and get titanium valves and springs, but it'd breath and work well and be reliable with your port and polish. not knocking on hot cam at all because you can do the same with them as well. ALSO, get a good exhaust, a slip-on is senseless if you race due to the stock headers usually aren't built to breath as efficiently with a P&P and engine work etc. compression and air flow are everything, displacement just gives it a LIL bit bigger area to blow the mixture up on! (thats how i picture it :D )

x2

[atvhonda-rider]

i understand 440 is a good build as well, and i wasnt trying to knock it. but if you do go 440, HD studs are required as well as a more expensive head gasket to ensure it not blowing as easy, and im not saying they overheat so easily, but they do rather than the smaller bores... im simply saying 416 or 426 would be smarter for now IMO due to you can build a 416 to the same power, as said before by a fellow rider on this thread, find a good builder and you'll be set...