400ex Problems FEW MORE QUESTIONS!

[SYKO]

well I got my fiance' a 02 400ex, that was neglected to say the least, never had the oil changed much less the filter, the air filter had never been cleaned either. its running alot better now and is rideable, but....


say when you first start it up and take off it dosnt skip a beat, but after only a while once it warms up it spits and miss's a bit, The baffle is missing right now, and of course it wasnt ever jetted for that, and I expected a little poppin but it will loose a bit of power and really sputter...

Then if you take a chill pill for 20 mins and start up and take off it will run great untill it warms up again.

any ideas? could the baffle being gone effect it that much?

the spark plug may have never been changed either.. I guess I should hit that up now as well

anyone?

bueler?

bueler?

[SCEADU]

Sounds like jetting to me! Do those have an oil cooler? Maybe overheating.

[SYKO]

well its all stock except for the baffle missing out of the muffler even has the stock style honda air filter, with lid on the airbox.

it has the factory oil cooler on it, the motor dosnt feel overly hot just normal.

[SWIGIN]

cold=lean so a cold motor will run a tad leaner then when warm.

so if it runs good cold and if the problem is jetting it must be rich.

look at the plug and see

[Groundworx]

I don't think the baffle being out will affect the jetting that bad unless they tried to change the jetting. I get a lot of quads in without baffles and that usually doesn't affect them like that. I just sounds like crap. You might check your plug. My experience with the 400EX, plugs usually just completely quit with no warning at all. It will just die and not start again. However, if the quad has sat a while and not been ridden, that could be a problem. You should probably just go through and change all fluids, filters, and plug. Mabey even clean the carb out.

[SYKO]

there is fresh oil and filter in it, the stock filter I cleaned the hell out of it, but never changed the plug. I think I will do that today I dotn feel like taking th ecarb apart yet lol (lazy day)

[SYKO]

OMG how the F do you get the spark plug out? what size is it? my 5/8 plug socket wont even fit in the space where the plug is!? wtf? who made this design?

[SWIGIN]

lol....most new motors have plugs that are hard to get to...on most new quads you got to take the tank off.

dirt bikes too then i guess but i forgot to say in my last post that i never had to rejet for takeing out a baffle.

there was an old saying and i forget the exact % but it was like ''76% of the time a carb problem is realy an electrical problem''

[SYKO]

O you can get to the plug but finding something that will fit the hole to go on the plug is the problem

[honda250sx]

MUAHAHAHA....You have to buy the tool from Honda. Check the toolkit. I worked on one recently. The Honda sparkplug tool has the clearance needed!

http://i71.photobucket.com/albums/i151/brauerpower/DSCN3557.jpg

http://i71.photobucket.com/albums/i151/brauerpower/DSCN3558.jpg

[SYKO]

what tool kit? ive never had a machine with tools on it! lol! im not that lucky!

[honda250sx]

Unless your grinding the socket. This is the only way. Regardless thats what you need.

[SYKO]

is it a 5/8ths? what size is it?

[honda250sx]

I believe its 18mm.

[Jason Hall]

Syko, I have used a craftsman socket and got the EX plugs out. I want to say a 17mm for some reason sticks In my head. It needs to be a thin walled chrome socket. Once you get it loose, use a piece of 3/8 fuel hose to spin It the rest of the way out. When does It spudder, when you first throttle In, when your on the gas hard, just at a cruise? Is there a sign of black smoke when It's spuddering?

[SYKO]

thanx for the tip, no smoke at all, if you ride it hard it will sputter throught the powerrange, stumble a bit off idle, kinda like a fould plug on a two stroke. I will get a new plug before I go any further with it.

[Groundworx]

You don't have to have the one in the tool kit. I don't remember what size I used, but it was a regular plug socket. Believe it or not, the EX is actually one of the easiest to get to. Most of the newer quads you have to pull the tank off. You can get to the EX plug without it. Not easily, but you can.

[smokinwrench]

Your gonna love the 400ex once you get the bugs worked out. I had some bad luck when I bought mine but once I got that fixed it was perfect. I just gave my 400ex plug socket away a couple months ago or I would have sent it to ya. You can buy the tool kit dirt cheap from honda thats what I did, my ground down socket wasn't very good.

[Jason Hall]

Well let us know If the plug fixes It. If not, the 400ex carb Is VERY tunable. They have an adjustable accelerator pump. You might want to make a decision to keep the modded stock pipe, or get a slip on. I say this because If you tune the carb to the pipe you have, then decide to switch you'll have to do it again.

[Groundworx]

Your gonna love the 400ex once you get the bugs worked out. I had some bad luck when I bought mine but once I got that fixed it was perfect.

I agree. IMO, the 400EX is one of the best "all around" quads you can get. It is simple, predictable, and reliable. It isn't the fastest by any means, but it is still quick. You can always have a lot of fun on a 400EX. It is one of my favorites.

[smokinwrench]

Mine was great, definantly needs aftermarket front shocks for agressive riding and an easier thumb throttle.

I put a 10.5:1 wiseco, stage 3 hotcam, cold air intake, slipon pipe, 1 bigger front sprocket. Dynoed at 35hp it would run with any stock 450. The handling is great on them. I wonder if the 450r handles like the 400ex?

[Groundworx]

Mine was great, definantly needs aftermarket front shocks for agressive riding and an easier thumb throttle.

I put a 10.5:1 wiseco, stage 3 hotcam, cold air intake, slipon pipe, 1 bigger front sprocket. Dynoed at 35hp it would run with any stock 450. The handling is great on them. I wonder if the 450r handles like the 400ex?

The 450R is similar to the 400EX in handling. It can handle the more agressive riding better than the 400. I would say of all the 450s, the Honda is the most trail ready/friendly.

[TravEX]

Syko, I got the stock muffler off of mine, if you need it, it may have 10 miles on it!

18mm socket and come in from the right side of the motor to get the plug out, they are easy to get out once you do it the first time. The socket wrench in the tool box works best, and I've heard of some guys grinding down the outer walls on a 18mm socket to keep on the quad, most sockets I've tried are very tight to get in there, I almost got one stuck in a buddies 400EX.

Once, you get it goin good, you'll love it, the 400 is a great quad. Had mine for 6 1/2 years, no problems.

[SYKO]

hey PM me on the muffler! its my fiance's so being all raced out isnt needed, so stock is fine, just trying to do other things like nerfs and new plastic and such.

thanx for the tip on the socket, i found its easy to get to if you stand the quad on its grab bar and just look right at the top of the motor.

[TravEX]

I also got some red race cut front plastic that would set if off great! I like em, but not too great where there's cow manure!

[SYKO]

Ok well I hit up my favorite motorcycle shop and they were kind enought to put a new plug in it for me, havnt rode it yet to see if it helped.

New QEUSTIONS:

has anyone improved the trottle pull? I meen this thing feels like im pulling a throttle on a deisel tracktor by hand! I know my fiance's little hands will get worn out quick like this.
I have taken springs out and shorten springs before to make throttles on my little stuff for my daughter to have it easier but never messed with a big bike.
And are the clutches on these bikes hard to pull? I feel like this is harder to pull then it should be

[ditchmud]

Yep the clutch and throttle are heavy to pull. When we first got my sons I thought something was wrong so I replaced the cables and they are still hard to operate. Maybe try another throttle housing from something else that might help.

Side note: When adjusting your clutch free play at the lever be sure to have the slot in the adjuster and nut facing upwards. The angle that the cable shoots down at will cause the cable to get cut through otherwise. That has been my experience.

[super90]

The clutch shouldnt be hard to pull. My friends 400 clutch is light as a feather. The clutch basket is probably shot.

[SYKO]

theres no notchyness to the clutch pull indicating a worn basket, its just plain hard to pull! Im pretty sure the clutch is near about ready to go out since this thing was so well taken car off. I may put one of those cheap pit bike hydro cluttches on this since there less then $50 so if it works it works if not then trash!

[TravEX]

Mine has never been that hard to pull, I keep it lubed good. I had a buddy put that EZ pull device on his clutch lever and he said it helped.

You got it fired up yet since the new plug?

[SYKO]

YEA IT RUNS a bit better, but havnt gotten to ride it hard yet, tomorow i will though.

[smokinwrench]

Yes throttles a hard to pull. Mines clutch never seemed that difficult.

You can remove a small spring from inside the throttle housing that helps. You can also install a thumb lever from a trx90 they are longer and make it much easier to push. As far as I know any year trx90 will work. I have the true honda manual for a 400ex to if you need any specs.

[rdlsz24]

Right click, save as for the factory service manual:

http://www.freewebs.com/honda-atc185s-rebuild/Honda_TRX400EX_Service_Manual.pdf

Rob

[TravEX]

Any updates on the 400?

You get your stuff today?

Travis

[SYKO]

got the stuff, will put the silencer on and ride it hard this saturday, we'll see if it was just a bit leaned out becouse of the open baffle, runs a bit better with a new plug in it, but still a bit choppy at times

[VABCH350X]

Since nobody else did, I'll toss in a vote for adjusting the valves, tank will have to be removed though. Beware the little plastic rivets, they are removable and reusable if you know how they work...sadly, I did not at first.:)

[SYKO]

I planned on going for that after putting on a baffled silencer on it as the jetting is stock and the baffle was taken off. If nothing changes with the stock baffle on the valves will be adress...

this is why I hate 4 strokes... if it dosnt start running like it should, I may rip it out and toss in a 250R motor... YEYA!!

[Erics350x]

have you pulled the carb, cleaned and adjusted it? i don't see the baffle causing any problems.

[SYKO]

well without a baffle it would be near the same as adding a slip on, more flow, causing a leaner condition since it of course wasnt jetted for it. So im hoping the baffle will return it to stock, I remember this machine when it had the baffle and it ran good not like it does now.

[200x350x]

check the valves

[SYKO]

put the baffled silencer on last night, thats a BIG improvement! need to get in a bit of seat time to see how she runs, if it still has some chopieness I will adjust the valves and clean the carb out.

[NOS_350X]

unlike everyone elce here i HATED the 400ex, For the throttle pull you can get a FCR carb, thats about the only way to make it easyer. I hated that 400 soo much i pulled it out and put that cr500 that you have now, in the quad.

[SYKO]

yea well its for my fiance' its a allright quad, hopefully later this year she will want a 450R or is she misses her 2 stroke I might put in a 250R motor, but she allready asked if it has reverse, wich it dosnt. So a quad with reverse will be on the menu next im sure, she cant pick this up as easy as the blaster.

[SYKO]

OMG what a DOG! it runs better, but it feels like it lost power now.....errrr..... I hate 4 strokes.....

ok well anyway, its my ladies ride but for future reference, what would be the quitest slip on silencer I can get for it? I would like to improve performance, but not make it loud like it was before, maybe just a bit louder then stock, wich sounds fine to me.

[TravEX]

There is not a quiet slipon. Even the quiet core ones are loud. All of the name brand ones good and perform basically the same. I have a white bros e series on mine and like it ok.

[SWIGIN]

I planned on going for that after putting on a baffled silencer on it as the jetting is stock and the baffle was taken off. If nothing changes with the stock baffle on the valves will be adress...

this is why I hate 4 strokes... if it dosnt start running like it should, I may rip it out and toss in a 250R motor... YEYA!!

this is why i never got into them, a 350rx will kill one and if you build them the topend studs pull out.

there is a fix for the stud problem but the 400ex in my mind has always bin hondas turd.

[SYKO]

well I have to fight the urge to do anything to this one swing, like I said before its my ladies whip, so if she tells me its to slow then im tearing into it!! or putting a 250R motor in it!

[TravEX]

The 440 kit is the only head stud problems I know of. They can be built strong, but hell, the stock motor is bullet proof. If you want the power of a 450, buy a 450. The 400EX is a great quad, no power monster, but a very fun quad to have.

Alan, go through the carb, set the valves and you're good to go. I set my valves about once a year if I ride alot. The maintenance on the 400EX is really a piece of cake, a hell of a lot easier than a fresh topend every year. Gas, oil, oil filter, valves, lube the chain, that's it.

[SYKO]

fresh topend every year? dont think so bro!

in any case, I think the no reverse factor might play a roll in keeping this one a long time, I want something that she will ride forever, and the trx450 will be the best bet, they come with reverse right?

[TravEX]

No reverse on the 450R's

[SYKO]

No reverse on the 450R's


well thats lame as hell..... geezzz... I guess she will just stick it out with the 400 then.... maybe she will be like... I miss my old 2 stroke! then I will be like HELL YEA!! sell the 400ex running gear and pop in a gold ol' 250R motor! ( I really REALLY hope she says that! lol)

[TravEX]

If you pull that motor, maybe I could trade ya out of it, hehe.

[SYKO]

If you pull that motor, maybe I could trade ya out of it, hehe.


whatcha got? :naughty:

[TravEX]

The 110 in my sig, I could part with it.

[SYKO]

lol! I thought you had a 250R motor sitting around! I think my fiance' would be upset if she wanted to ride and I stuffed a 110 motor in her 400ex!! LMFAO!

[TravEX]

O, my bad! I thought you had an R motor laying around the way you were talking! Lol