not enough power...

[metalhead95]

I bought an 07 400ex earlier this year, actually 2 of them. One for me and one for my son. The trail riding at Wayne and this weekend went to Richland furnace, contains some trails where you have a sharp turn then an uphill climb, which I have to drop into first because 2nd is to sluggish. Then if the straights get too long I have to go to third for 3 or 4 sec because 2nd is revving out, Then drop back to 1st to come out of the corner. The problem is I think I have shift way too much. If 2nd had more power and revved out higher, I think I would spend less time shifting up and down, up and down. I went 1 down on the front sprocket to try to get more low end power and I think all that did was create more shifting. Another thing, if I am climbing a hill I have to stay in 1st to the top unless I get one hell of a start and use momentum in 2nd, but if the hill gets too high 2nd will bog out and I have to shift back into first mid to 3/4 way up. I am not talking extreme hills either just long inclined trails through the woods. I have been reading about 416, 440, stage 1 and 2 cams and high compression pistons in previous posts. I am not sure what fits me. I like what I see about stage 2 cams. Also I would like to keep some top end, but I am not a racer and would like to continue using pump gas. What advice do you have?

[Hondamaster5505]

If you want to get up hills, get a different quad.. I go through the same thing.

But, ive practiced enough to do it where I can retain speed in 2nd, and just turn and rip up the hill.

It sucks though. Unlike a banshee or 450 that hold power up the whole hill sometimes, the 400ex just starts to drop dead.

If you don't want to bother with another quad,

What type of riding do you do? Fast? If so, I would go with:

440 Big Bore
11.1 Compression
Stage 2 cam
450r FCR carb
Decent exhaust
And if you really get into it, some porting.

If you're worried about it getting real hot, go with all the same as above but with a 416 instead of a 440.

And if you have a lot of money, I think a 440 stroker is the way to go for you. It's an 87mm piston with a +4mm stroke. It would give you a ton of torque for climbing hills.

[metalhead95]

I forgot to add, I do have a pro circuit exhaust system.

[gcart2]

Originally posted by metalhead95
I forgot to add, I do have a pro circuit exhaust system.


sorry to say it but.... buy a 450.

[metalhead95]

I have ridden 450's and they are too much for me. Besides I just bought these so obviously I can't just run out and buy a 450. From what I gathered when 3 of my riding buddies had 450's they are temperamental maintenance nightmares. I like to ride atv's not work on them if you know what I mean. They were constantly tweaking things and tearing them apart for this or that. Ridiculous. Sorry but owning a 450 is not an option.

[bigbad400]

thats wierd to me cuz i dont got any more real mods than you and i can dump it in third at the bottom of a sand dune with holeshots on and it will gain speed till the top. are you like 300lbs, cuz im 160 and its easy for me. but a good start is a good intake, veocity intake with the k&n and such will open it up too.

Originally posted by metalhead95
I have ridden 450's and they are too much for me. Besides I just bought these so obviously I can't just run out and buy a 450. From what I gathered when 3 of my riding buddies had 450's they are temperamental maintenance nightmares. I like to ride atv's not work on them if you know what I mean. They were constantly tweaking things and tearing them apart for this or that. Ridiculous. Sorry but owning a 450 is not an option.

that is the exact reason i traded my 450r and went back to the 400ex...

work on the suspension, it will let you take turns better, therefore going faster...after the suspension work get and exhaust and and after market air filter and make sure it is jetted properly after that...doing those 3 mods(suspension/exhaust/filter) will make a big difference

[metalhead95]

Originally posted by bigbad400
thats wierd to me cuz i dont got any more real mods than you and i can dump it in third at the bottom of a sand dune with holeshots on and it will gain speed till the top. are you like 300lbs, cuz im 160 and its easy for me. but a good start is a good intake, veocity intake with the k&n and such will open it up too.

I am about 175lbs

[Wheelie]

As stated before, if you have fairly deep pockets and want a quad that rips--build a stroker.


For less than $500 (if you do the work yourself) you can build a solid running ex that won't break the bank. A 10.8:1 416--still pump gas friendly, HC Stg 2, open up the airbox and install a slip-on. The slip-on will push it over the 500 dollar mark, unless you find a good used one.

[MtnEX]

I'm searching for the answer to this puzzle myself.

I wanted a torqy quad with great handling that I could ride slow through the tight woods and rip when I got the chance... and maybe play on the track a little.

So far the 400EX is proving to be close, but no cigar....

I can tell you first hand that the 450R's are NOT the answer to this puzzle. The YFZ had explosive power, and I think actually LUGGED the gears a little better than the 400EX... but reality is, all of the 450's love to rev and are high strung... a bit much reving and clutching for tight rides.... pretty close to the old 2-strokes I used to ride.

Metalhead,

What gearing are you running?... I'm at 14/38... and trying to decide which way to go... up to stock 15/38... or on down to 13/38 like I'd planned...

Our trans ratios may be a little different, but for me, 14/38... second is OK but revs out fast, and third doesn't have much balls... so I spend a lot of time shifting between the two, and into first sometimes here and there too... way more shifting than I was hoping for.

It should have a crawl gear, a hill gear, and a really wide range gear it can pull from a lug to high rpm, and it just doesn't have it.

The K&N and exhaust really haven't done a lot for it either. All the stuff we are talking here about aftermarket improvements... we're still talking 25-28hp from stock to piped/jetted/etc... not a lot of gain.

It's getting better and I'll keep tinkering with other enhancements and gearing... but I'm not particularly fond of the big bore kit idea... and if I had to do one I'd certainly stay below the 440.

I knew this thing wasn't going to be as fast or make as much power as my Sport 400. But I sure expected it to have a lot more grunt and torque.

Yeah, my Sport 400 goes from 0 to 40hp in seconds... but it's also 100lbs heavier, automatic and 2 stroke. It still spanks the EX with extreme ease, on everything but extremely slow riding... like 1st gear crawling work. Up hills... that ain't even a fair comparison... the Sport 400 is a top dawg hill shooter.


All this leaves me wondering what the heck Honda is thinking sometimes. Myself, I think they ought to have built a true sport 650EX... with the engine from the XR650R... instead of the 700XX thingy. But I guess they didn't want to have to compete with the Yamaha 700R directly like that?

[exrider272]

the good thing about 400s are that parts are cheap there easy to work on. and you can build them to eat 450s without dumpin loads of money into it

[AZ440ex]

[/B] [/QUOTE] I have been reading about 416, 440, stage 1 and 2 cams and high compression pistons in previous posts. I am not sure what fits me. I like what I see about stage 2 cams. Also I would like to keep some top end, but I am not a racer and would like to continue using pump gas. What advice do you have? [/B][/QUOTE] [/B]

I think there is some small stuff you may try before going to a bigger bore.

Remove the air box lid. Ditch the OEM filter and inner cage. I run UNI, Twin Air etc. Just keep them clean and they are great.
Might need to re-jet. There is about a million threads on this, my only recomendation for jetting is do what is right for your bike in your area. I have seen main jet size recomendations from 150-200?!?. There is no one solution!

You may try a different rear sprocket. One tooth on the front is about 3 on the rear. I dropped a tooth in the front for MX and found I was shifting too much. Turned out 2 teeth on the rear was perfect. Just an option to think about.

The stage two cam might not give great gains on a stock bore but it's not a bad investment if you plan future mods. It is a good mid-top end cam.

A rev box might get you the extra rpm's you need. Also will go good with other mods.

A sparks timing key (Never had one but they are supposed to be good on stock motors, advances the timing like 6 degrees)


If you do go big bore build it right and it will be reliable. (the manual has TQ specs for a reason, not using a TQ wrech is being lazy)I have run a 440 for 6 years now with no problems.

As for pump gas, if you can find a good station with clean fuel and stay below 11:1 you should be fine. (I inspect fuel staions for my fire dept. After talking to the contractors and seeing the fuel tanks and corrosion there is very few stations I trust)

[Duke Nukem]

I know it's expensive, time consuming, and you never know if your going to be happy with it or not. But, when I did my 440 stroker I loved it. Makes more low end power than my dad's HRC 450R, and it's a great all around quad from all the improvements I have made to it. I can shoot up hills in 4th or lugg up them in 5th.
Just an idea though.

[REPOMAN]

the responses are hilarious in this thread. a 400 will not beat a 450 the rider of the 400 might beat the rider of a 450 but thats that. i had thousands and thousands in my 440 and thought the same thing until o got a 450r. i dont have to do any work on my 450r but was always working on something with my 440. gearing and suspension are going to be the place to start for you. that is my opinion anyway.

[Duke Nukem]

Originally posted by REPOMAN
the responses are hilarious in this thread. a 400 will not beat a 450.


You must have had a problematic EX then. Mine and alot of other EX's can with ease.

[powermadd400ex]

Originally posted by Duke Nukem
You must have had a problematic EX then. Mine and alot of other EX's can with ease.
:rolleyes: repoman is right a 400 cant beat a 450. but the riders can make the difference.
let me put it this way if you want a fasst quad the 400ex isnt the quad for you. stock it hits 69 MAX. if you want fast buy a 450.
like stated before in your case metalhead, a 416 or 440 is your best bet along with suspension it should handle great and take hill alot easier.

[leasureryan]

I'm having the same problem

[AZ440ex]

Originally posted by REPOMAN
the responses are hilarious in this thread. a 400 will not beat a 450 the rider of the 400 might beat the rider of a 450 but thats that. i had thousands and thousands in my 440 and thought the same thing until o got a 450r. i dont have to do any work on my 450r but was always working on something with my 440. gearing and suspension are going to be the place to start for you. that is my opinion anyway.


You must have had a problematic EX then. Mine and alot of other EX's can with ease.

I thought the idea of the thread was to help the man out with a little power?
But if we are going to get off the subject!

Yes 440's are strong may beat a 450 in a race but as said above there it is more the rider. Don't get me wrong, I LOVE MY 440 and I can beat a 450 or two but the DYNO does not lie.

MY 440 dyno's at 46-48hp depending on fuel, how fresh the top end is etc...

My 450r motor is 54-55hp, stock bore, cam, ported.

Seriously, Would you agree that Factory Honda Mechanics probably can take the motor to its fullest potential?
They chose to run 450's for a reason, it's a better motor. Liquid cooled motors have so many advatages.
Why do you think HYBRIDS dominated before factory production rules?

[MtnEX]

Originally posted by AZ440ex
I thought the idea of the thread was to help the man out with a little power?
But if we are going to get off the subject!

Yes 440's are strong may beat a 450 in a race but as said above there it is more the rider. Don't get me wrong, I LOVE MY 440 and I can beat a 450 or two but the DYNO does not lie.

MY 440 dyno's at 46-48hp depending on fuel, how fresh the top end is etc...

My 450r motor is 54-55hp, stock bore, cam, ported.

Seriously, Would you agree that Factory Honda Mechanics probably can take the motor to its fullest potential?
They chose to run 450's for a reason, it's a better motor. Liquid cooled motors have so many advatages.
Why do you think HYBRIDS dominated before factory production rules?

Your legs and the condition of your oil will tell you some about the advantages of liquid cooling... and it goes so-so much farther beyond that. The main thing is that being able to cool and control the temperature better.... this allows so much more to be done inside the engine to make power.


I'll agree with you too... there is a big gap between the 400EX and any of the 450's... BIG GAP! The YFZ made way more power than this 400EX. Big gap... And in my opinion it is one that is not really worth trying to close. Want to make the 400EX better?... Fine... Want to try to make 450 level power... what's the point?... Just get a 450.

I went to the 400EX because it is simple, air cooled, hard to hurt and low maintenance. But I'd be gone back to the 450's in a second if I could learn how to extract some low end grunt out of them and make them better for some of the tight woods riding I do.

[REPOMAN]

Originally posted by Duke Nukem
You must have had a problematic EX then. Mine and alot of other EX's can with ease.
it makes more sense to say you were racing "problematic" riders. the only realway to make a 400, 416, 426, 440 is to drop a 450 in it. tell you what. i will pay for your gas to come here to new mexico and even give you a place to stay and i will prove it to you. :D i am not trying to argue or ruin this thread but i had over 12 grand in my quad and it was by no means problematic. i thought i could beat a 450 also but i was just beating riders.

[Duke Nukem]

I completley understand what your saying ;) What I meant was a EX setup like mine vs. a stock 450R, then we are in the same ballpark. But take a modded out 450 and yeah no way any EX could take it.

[metalhead95]

Originally posted by Duke Nukem
I know it's expensive, time consuming, and you never know if your going to be happy with it or not. But, when I did my 440 stroker I loved it. Makes more low end power than my dad's HRC 450R, and it's a great all around quad from all the improvements I have made to it. I can shoot up hills in 4th or lugg up them in 5th.
Just an idea though.

Wow; lugging 4th and 5th, it must be a real torque monster.

[metalhead95]

Sorry fellas; I didn't mean to start a 450 v/s 400 war.

What exactly does the rev box do for you? Other than hence the name. I do have a uni filter but I can't remember the jet size I put in when I put the exhaust on. I'll have to check that out. I would like to leave the airbox lid on for the times that I approach water in the woods. When I put the stock 14t front back on that did stretch out the gears a little so I think I am on the right track. The gearing is close to right, now I just need to build a little more power in each gear. I saw that you can get different compression pistons. If I bought the stage 2 cam, would or should I change the piston? I really don't want to change the jug just yet. Looks like it's quite a few more $$ to go that route. For about $160 the cam seems like a good place to start; at the heart of power production, or am I thinking totally wrong?

opinions?

[AZ440ex]

Originally posted by metalhead95
Sorry fellas; I didn't mean to start a 450 v/s 400 war.

What exactly does the rev box do for you? Other than hence the name. I do have a uni filter but I can't remember the jet size I put in when I put the exhaust on. I'll have to check that out. I would like to leave the airbox lid on for the times that I approach water in the woods. When I put the stock 14t front back on that did stretch out the gears a little so I think I am on the right track. The gearing is close to right, now I just need to build a little more power in each gear. I saw that you can get different compression pistons. If I bought the stage 2 cam, would or should I change the piston? I really don't want to change the jug just yet. Looks like it's quite a few more $$ to go that route. For about $160 the cam seems like a good place to start; at the heart of power production, or am I thinking totally wrong?

opinions?

The stage 2 cam won't hurt but you will not see it's full potential on a stock motor. A stage 1 is better for bottom end but if you ever mod the motor you will want the stage 2.
Shop around, you should be able to get a cam for $130 or so.
Being air cooled and the type of riding your doing I would say no to the high compression piston. When you do the cam you could replace the head gasket with a xr400 or cometic 3 piece steel one. They are both thinner giving a little more compression. A 10:1 is really not a 10:1 until some things are done.
Read through this article. I think there is valuable info for 400ex owners. It explains some compression issues etc...
http://www.atvriders.com/articles/askmickey1.html

[AZ440ex]

Oh, i forgot. The rev box will usually give you about 1,000- 1500 more RPM depending on the brand. I think some even changing the timing curve a bit.

I saw some for sale in the classifieds for like 40 bucks. they are about 100 new

[metalhead95]

Originally posted by AZ440ex
Oh, i forgot. The rev box will usually give you about 1,000- 1500 more RPM depending on the brand. I think some even changing the timing curve a bit.

I saw some for sale in the classifieds for like 40 bucks. they are about 100 new


Are they worth the money? Will it add to my attempted solution?

[project400ex19]

try different gearing...i would drop a tooth in the front (14) this helped me a lot when i was younger and climbed a lot of hills at gravel pits. It's cheap and easy to do also. Then I'd go for engine mods, pipe, jetting, cam, piston.

I run a 416 which is bored 2mm over (87) 10:1 compression with a stage 2 hotcams and a 450R Carb, CT Racing full exhaust, I noticed a huge difference with these mods.

[AZ440ex]

Originally posted by metalhead95
Are they worth the money? Will it add to my attempted solution?

How much power will it add? Not sure, I added mine when I did the Big bore. If you can get one cheap I think its worth it for you. Combined with a cam and stuff it should help out.

Maybe a 450r carb, new they are $160 and ZRpilot has some adapters for it. seems to be a pretty popular mod

Search sparks timing key, it seems to be an alternative to these. I have no experience with them but there is lots of people on here with them. I think its only 30 bucks.

good air filter and exhaust do make a noticable difference but not a big gain until you change some other things and that 2HP you saw from the exhaust and airfilter on a stock engine could be so much more if you start changing the cam and piston. My quad runs real strong with the mods I have. It could have more power but I don't need more power. I am completly done with performance mods until I get my suspension rebuilt and a few other things. There arent many hills that I cant climb the only thing that stops me from climbing is my front end going up on the hills. I have climbed through the gears to 4th up a hill but it wasnt real steep. Steep hills 2nd gear for me I can just fly up. The only time I have gone full thottle up a steep hill was when there was a 4 foot cliff at the top. I mean this was a 4 foot cliff straight up it was almost like hitting a wall and it was fun while it lasted lol

[metalhead95]

Originally posted by FoxHondaRider
good air filter and exhaust do make a noticable difference but not a big gain until you change some other things and that 2HP you saw from the exhaust and airfilter on a stock engine could be so much more if you start changing the cam and piston. My quad runs real strong with the mods I have. It could have more power but I don't need more power. I am completly done with performance mods until I get my suspension rebuilt and a few other things. There arent many hills that I cant climb the only thing that stops me from climbing is my front end going up on the hills. I have climbed through the gears to 4th up a hill but it wasnt real steep. Steep hills 2nd gear for me I can just fly up. The only time I have gone full thottle up a steep hill was when there was a 4 foot cliff at the top. I mean this was a 4 foot cliff straight up it was almost like hitting a wall and it was fun while it lasted lol


It sounds like you have exactly the power range I am looking for. I want enough to do about anything I am comfortable to attempt without running out of power but not overkill. Can you guys give me a parts list of what I am going to need for the cam change, other than the cam obviously :rolleyes: , but any gaskets or things I might replace while its apart? Keep in mind it's only six months old, and has not been rode hard and put away wet.

Thanks,

[Hondamaster5505]

Originally posted by FoxHondaRider
good air filter and exhaust do make a noticable difference but not a big gain until you change some other things and that 2HP you saw from the exhaust and airfilter on a stock engine could be so much more if you start changing the cam and piston. My quad runs real strong with the mods I have. It could have more power but I don't need more power. I am completly done with performance mods until I get my suspension rebuilt and a few other things. There arent many hills that I cant climb the only thing that stops me from climbing is my front end going up on the hills. I have climbed through the gears to 4th up a hill but it wasnt real steep. Steep hills 2nd gear for me I can just fly up. The only time I have gone full thottle up a steep hill was when there was a 4 foot cliff at the top. I mean this was a 4 foot cliff straight up it was almost like hitting a wall and it was fun while it lasted lol

If you think the 400ex is a good hillclimber, you obviously never rode a 450 or banshee up a hill. lol.

I take my 400 up a hill, and, ehh, it made it but struggled a little.

Then i hop on the banshee, and it literally makes hills feel easy.

I don't like the 400 for big hills at all. It starts to bog down so easily because the power is on the lame side.

For blasting around trails and such, it's fun. But take it somewhere with hills, and it's so lame. its not a powerhouse at all.

[AZ440ex]

Originally posted by metalhead95
It sounds like you have exactly the power range I am looking for. I want enough to do about anything I am comfortable to attempt without running out of power but not overkill. Can you guys give me a parts list of what I am going to need for the cam change, other than the cam obviously :rolleyes: , but any gaskets or things I might replace while its apart? Keep in mind it's only six months old, and has not been rode hard and put away wet.

Thanks,

If you are not going to mess with the piston or head gasket it should be just the cam, stuff for an oil change, feeler guage for setting the valves. You may need a valve cover gasket but probably not. Mine has been fine and I pull it periodicaly to TQ check my head bolts.

If you do a piston swap then you will need a new head gasket.

Originally posted by Hondamaster5505
If you think the 400ex is a good hillclimber, you obviously never rode a 450 or banshee up a hill. lol.

I take my 400 up a hill, and, ehh, it made it but struggled a little.

Then i hop on the banshee, and it literally makes hills feel easy.

I don't like the 400 for big hills at all. It starts to bog down so easily because the power is on the lame side.

For blasting around trails and such, it's fun. But take it somewhere with hills, and it's so lame. its not a powerhouse at all.

i have rode both, 450's seem to be a little rev happy and so do banshees. Banshee's seem to just spin and never make it up any of the hills near me and 450's will do just fine. If you ask me I say you want torque to climb which is where a 4 stroke accels. Have you jetted your 400ex yet? 400ex bog when they are lean too.

[400ex28]

idk about yall but my ex never bogs down.

but i dont trail ride

[AZ440ex]

Originally posted by 400ex28
idk about yall but my ex never bogs down

Mine bogged once, but I was pulling some Yahmacrap up the hill behind me. :D :D :macho

[Hondamaster5505]

Originally posted by FoxHondaRider
i have rode both, 450's seem to be a little rev happy and so do banshees. Banshee's seem to just spin and never make it up any of the hills near me and 450's will do just fine. If you ask me I say you want torque to climb which is where a 4 stroke accels. Have you jetted your 400ex yet? 400ex bog when they are lean too.

Yeah, I jetted it a while ago.

450's and banshee's being rev happy are what make them good climbers. They rev up and hold power.

Idk what your talking about with banshee's. They didn't get the nickname king of the hill for no reason. It may be different with woods climbs, but coalmine and dune climbs, the banshee will go up anything. That;s what i love about it.

It's actually top end that gets up hills too, at least in coalmines, which is why the four-strokes dont accel. They want to grip too much and get traction, making them bog down occasionally. The 2-strokes get in powerband and hold it, almost paddling themselves up it.

[Hondamaster5505]

BTW: so I don't confuse people.

The hills it bogs on sometimes are in ashland. The 400ex in the woods though, will climb anything in 2nd gear