Honda 400ex bore question?

[BenHonda400ex]

This christmas I'm getting a sparks x-6 exhaust and new oem plastics... Well I was wondering If the 440 big bore kit will burn up your engine and make you have to rebuild it alot? Is there a that much difference in power wise between the 416 big bore kit and 440 big bore kit?http://

[beags86]

no and yes....

[BenHonda400ex]

What do you mean by that?

[CJM]

440 is awesome in the respect it makes alot of power. Problem is if you dont do things like heavy duty head studs (some will argue they arent needed, it is debatable but imho you need them) you may blow a head gasket.

The 440 it creates alot of heat b/c the cylinder wall is much thinner and if something happens where you needed to bore it you need a whole new cyl or the insert needs to be replaced.

Personally speaking unless you want to race I dont see needing a 440 except to show off if all you do is casual riding on trails.

Thats just my opinion, but its up to you in the end.

If I were you I would sink my cash into a stage 1 or 2 hotcam and a simple slip on since a full exhaust may only gain you a tad bit more power. Where you save your cash on the exhaust you can put the cam in. It will make the quad that much faster. Im quite happy with my slip on, II hotcam and 416 bore w/11:1 piston.

[beags86]

i was kind of waiting for some of the more opinionated members to speak up.... in my opinion a properly built 440 (i.e. H.D head studs, spall fan, oil tank,etc. )should not sacrifice any reliability.
so in my opinion a properly built 440 will have more power then a 416. honesty i myself have not ridden a 416, but i have ridden a 440 and 406, they had similar mods but not excactly the same, and the 440 was much faster.

i myself would skip the rebuild until you have jetted the carb to match your new pipe, install a sparks key, opened up your air box and upgraded to some 450r or aftermmarket front shocks.

[beags86]

Originally posted by CJM
440 is awesome in the respect it makes alot of power. Problem is if you dont do things like heavy duty head studs (some will argue they arent needed, it is debatable but imho you need them) you may blow a head gasket.

The 440 it creates alot of heat b/c the cylinder wall is much thinner and if something happens where you needed to bore it you need a whole new cyl or the insert needs to be replaced.

Personally speaking unless you want to race I dont see needing a 440 except to show off if all you do is casual riding on trails.

Thats just my opinion, but its up to you in the end.

If I were you I would sink my cash into a stage 1 or 2 hotcam and a simple slip on since a full exhaust may only gain you a tad bit more power. Where you save your cash on the exhaust you can put the cam in. It will make the quad that much faster. Im quite happy with my slip on, II hotcam and 416 bore w/11:1 piston.

basiclly what i meant by some of the more opinionated members, cjm, steve, ron, etc.

they all have good opinions and different views,

just remember what you want to do with your quad and build it to suit....

cjm- if the kid wants a 440 then who are we to stop him...
every gearhead always wants more and
everybody falls victim to the snowball effect

[BenHonda400ex]

I don't do ANY racing at all! I just want a trail bike that people can't keep up with. Would you be able to get as much horsepower as a full sparks exhaust from a slip on?

[beags86]

no... most slip on are close to the same power output.. some being higher then others.. but a full sparks system puts out the most power, in the tests i have seen

[beags86]

Originally posted by BenHonda400ex
I don't do ANY racing at all! I just want a trail bike that people can't keep up with.

buy a 700xx

[BenHonda400ex]

Originally posted by beags86
buy a 700xx
My friend has one but I don't like the independent axle... But they do have alot of horsepower..

[BenHonda400ex]

So how hard is it to install a hot cam on a Four-wheeler?

[CJM]

Easy really.

All you gotta do is set timing, remove the valve cover and yank it out, and put the hotcam in (ok well thats the cliff notes version). This explains it better, but its not hard at all: http://www.lspsonline.com/howto/400ex%20hotcam/index.htm

[BenHonda400ex]

How much doe's it cost for a shop to install a 416 bore kit? And is there any power difference from a 416 bore kit? Thanks!

[honda400ex2003]

im taking the night off lol ill report back my opinion tomorrow lol steve

[CJM]

Originally posted by BenHonda400ex
How much doe's it cost for a shop to install a 416 bore kit? And is there any power difference from a 416 bore kit? Thanks!

Depends on the shop and what parts you use really.

Its not hard to do yourself with the manual and some basic tools. You do need some special stuff like a torque wrench and feeler gauge among some other items but your basic metric socket and wrench set will do it. If you havent ever worked on it and have some mechanical expierance it isnt to tough-if you dont know much it would probably be a good idea to pay someone to do it or at least have someone who knows whats up to help you.

You must send the cylinder, and your piston out to a place to have it bored. A machine shop can do it, and there are several motor builders aorund like hung racing, CD racing, GT Thunder, etc.

There is of course a power difference of a 416cc to 440cc (actually 435c iirc). You have much more displacement with the 440-but like I said (and its your call in the end) it creates alot of heat and can blow headgaskets easy in some cases. Dont get me wrong its an awesome setup but reliability is lowered in the end in my opinion. However some dont have any issues-me I play it safe to be sure. I did a 416, specs are in my signature and trust me it rips more than enough for me vs stock. The higher compression piston and cam are what really does it I think.

[dirtrider77]

here is my opinion, take it for what its worth:

if you want a trail quad nobody can keep up with then sell your 400 and go take out a loan

there is no need in a 440 kit....yes they are sweet, yes they are fast, and built properly and well maintained they can be reliable....however they are not practical in most situations

if you want a sweet reliable 400ex that you can go out a crank up every day and not worry about anything then i would recommend:

as far as exhausts are concerned, the sparks is great hands down....good choice

yes a 440 is faster than a 416! yes a 416 is faster than a 400....

hot cam installation is definitely high up on my list! best mod i have done thus far! recommend stage 2

......so if i were you i would do this....buy a hot-cam, install your exhaust your getting, if your wanting that extra power go on up to a 416 and get a 10:1 piston...also invest in a uni or k&n if you haven't already

then take the time and jet your bike properly or you have wasted all that money on parts

as far as shop costs, most places charge about $50 to bore your cylinder, and here they charge $70 to install the parts......you will have about $135 in piston rings and gaskets and $130 in hot-cam

So.....

internal motor parts ~ $265
shop labor ~ $120
total = $385

now, another recommendation i have is to save $70 or so and install the parts yourself (you still need to send cylinder & piston off for boring) .....there are plenty of how to guides to assist you

...now im done rambling...if you have anymore questions please ask (:

[hiway6969]

you want a 400 that no one can keep uo with on the trail???? well go out and ride, practice, and ride harder! make your self faster before you make the bike faster, save your money for wear and tear parts like chain/sprockets and brake pads and oil/filters that you will wear out riding your bike more often and eventually faster. just stating facts, its not always the bike. i race a 400 in xc races , got a wall full of #1's to prove my sweet 400 spanks 450s and those pesky ktms that are like 900's lol

[bbender85]

i ran a 426 piston in my EX. 11:1 and all the basic supporting mods (hotcam, intake, pipe, 450 carb). was dependable for me with the exception of the headgasket i blew. had GTT heatstuds installed, put fresh gaskets in and it ran great until i parted it out. i'd have to guess a 426 sleeve is about as thick as a 440, since the cylinder is bored to fit the bigger outside diameter of a 440 sleeve when installed (which is another cost you have to keep in mind).


if i were you, i'd go with an 11:1 stockbore piston in, or if you need a top end rebuild right now just go up a size. with good compression and a cam to match you'll make good power. i think the reliability of a smaller bore with increased compression and a cam will outweigh the minimal horsepower gain of the 440, plus you have cylinder left to bore next time it needs a rebuild.

[brandon400]

my friend had exhaust and a rev box on his 400, and a stage one cam didnt do anything at all, am i retarded or did he need a piston with it?

[dirtrider77]

Originally posted by brandon400
my friend had exhaust and a rev box on his 400, and a stage one cam didnt do anything at all, am i retarded or did he need a piston with it?

if a cam didnt do anything...something is bad wrong lol

piston is not mandatory

maybe when he installed it he got the timing off or something

[BenHonda400ex]

Doe's anyone have a link on how to rejet a carb?

[honda400ex2003]

check the stickies, there are quite a few good ones in there. lots of tips also in many different threads. check out Jets R Us also and their FAQ section that has some really good tips also. steve

[honda400ex2003]

http://www.jetsrus.com/FAQ_selection.html

http://www.exriders.com/vbb/showthread.php?s=&threadid=445695&highlight=jetting+placement

http://www.exriders.com/vbb/showthread.php?s=&threadid=394028



steve

[BenHonda400ex]

Should I go with the stage 2 or stage 1 hot cams?

[honda400ex2003]

do you want more low end or top end? low end and mid get the stage 1

mid and top end get the stage 2

Both are great cams but they have their places when wanting power in a place. it also depends on what compression you have too. decide everything else you want to run before choosing your cam. then we can help you as to what cam to run with a particular setup. steve

[BenHonda400ex]

Well I'm getting a Curtis Sparks exhaust x-6 and a 416 bore kit so what cam should I get?

[honda400ex2003]

what type of riding do you do? you have a top end pipe, what compression are you running and where do you want your power. if you want to match your pipe then get a stage 2. you will probably be much happier with it no matter what compression you are running. especially if you ride faster trails or open areas more.

the stage 1 is known for its low end torque and good mid range but not for top end.


ill give you a bit of an example now. I like to have a well rounded machine- so what i would do is run the sparks with a stage 1 and have a good compromise of everything. others will argue that the stage 1 will not really see its full potential since you are running the full exhaust... but... with a great top end pipe, and a lower end cam you get good mix of low end, good mid, and good top. I get mild port and polishes to help with the overall flow of things also. I set my engines up like that though for trail riding and very occasional track times.

My vote will most likely go to stage 2 anyway no matter what the circumstance you choose just to go with the pipe and have nice top end and mid range.

just my .02 though, steve

[BenHonda400ex]

I do some trail riding but mostly I'm going running 3rd or 4th gear... Like at Saint Joe state park where we usually go to it has sand and trails but mostly we stay on the sand... Thanks for answering all my questions!! Just got one more question do you need to run a stage 1 or stage 2 hot cam if you put on a 416 kit or just can you keep the stock cam?

[dirtrider77]

you can keep stock cam

however while it was apart id spend $130 and buy a cam

i have a stage two and i ride alot in tight woods and on a track...seems to work great both places...deff reccomend

[CJM]

I like the stage 2 cam, I have a 416 and really keep in the mid rpm range anyways.

[honda400ex2003]

my vote goes to stage 2 now that you said how you ride.

you can keep the stocker as said above too if you prefer. it will be a real low end cam. lol steve

[BenHonda400ex]

Dang now I can't wait for Christmas!! I'll have the fastest Four-Wheeler in the group, I don't right now because my friend has a stock dvx 400 and I have the stock 400ex and he just whips my butt sometimes

[dirtrider77]

haha yeah the dvx, ltz, and kfx line are a little quicker

i have a 400 with mods almost identical to what your wanting to do, and my dad has a z400 with full exhaust, k&n and powerlid and they feel about the same

so if your buddies is stock, you should be good

if you rack up this xmas, grab you some used shocks...get your rear done by gt-thunder and a good set of any brand fronts set up for you will make you way faster

...i never believed it until i tried it

[rinconrider]

Def some good info in this thread for us new guys! Thanks for all of the setup info guys!

[blwn3800gs]

I'm also new to a 400ex,but traded a 00 polaris sportsman 500 for the honda i have now.This one was built by the guy i bought it from with the 416 kit. All i've got to say is this machine is a blast to ride,it pulls hard and always want to come up in a wheelie. Starts real easy and so far no problems. I couldnt be happier. I'd say go for the 416 kit also,will be a blast for sure. check out my sig,should give you some ideas.

[BenHonda400ex]

Doe's the 416 bore kit destory your engine? My dad keeps telling me that it will destory my engine

[dirtrider77]

Originally posted by BenHonda400ex
Doe's the 416 bore kit destory your engine? My dad keeps telling me that it will destory my engine

No no no no no......your dad, like most of us kids dads grew up in a time when things were not made the same...back in the day modding engines wasnt as reliable as it is today...however things have changed and things are made differently in todays world

trust me, i had to convert my dad over and pop his "stock cherry" lol

i have seen many friends with 416s and they have had no more problems than anyone elses bike

it all comes down to doing it right and taking care of your bike

16cc is not like 40cc.....your engine will be fine

go ahead and get 416 keep it for months to show him its fine, and then you will be good to go haha

[CJM]

mine keeps on going and going and going, no issues at all besides some carb tuning.

[dirtrider77]

Originally posted by CJM
mine keeps on going and going and going, no issues at all besides some carb tuning.

just like the energizer bunny :p

[blwn3800gs]

Originally posted by dirtrider77
just like the energizer bunny :p


lol, Like everyone else says go ahead and do it and dont worry about any problems. Cause you shouldnt really have any! Good luck with your project!

[BenHonda400ex]

So do you think if I asked a dealership if it will destory the engine what do you think they will say? Because if they say it won't then my dad might buy it

[blwn3800gs]

i dont know what a dealer would say,they might just talk you into the stock set up just to be on the safe side. Just tell your dad its a honda they have great motors,so you should be safe with the 416kit as a upgrade.

[honda400ex2003]

they should say that it wont but some guys are just like your dad at dealers, i get that from my dealer every time i go in to get jets. i get the 100 question test as to why i am messing with my machine again. lol steve

[dirtrider77]

lol yea a guy here at my dealership, im friends with both of his sons, one who is pro, and all he preaches is stock lol...the man even buys oem grips

haha great guy, but some people are just set in there ways

tell your dad you want money for xmas....then order the parts online (: