desperate for help....

[DieselBoy]

I have a 2000 400ex stock, new rebuild, I'm trying to make it run so i can ride. It's getting fuel, I replaced the coil, it ran beautiful when i parked it, and now a couple month's later it's being a bugger. It so badly want's to start but something's wrong...

It's kicking a bit, but it's just not enough to make it run. WHAT could be wrong? new plug/coil/cap/wire, There's so many electric components, and so expensive, I don't know what it is. What do you thinkit could be?

notes:
stock cdi, nothing in that regard has been changed.
kill switch on, neutral switch on.
new coil, spark but may not be consistant or strong
its not a constant kick, but every once and a while
freshly rebuilt, but ran phenominal after rebuild

could something be wrong with the cdi/rectifier?

when you say rebuild what did you do??? you might want to check you timing, or valve clearance to start.

[Iliketogofast]

400EX's are always a ***** to start after sitting for a while. Make sure you have the choke on and maybe change the pilot up one size. The more gas it's getting the better chance it has to burn.

[450rrider69]

clean ur pilot jet out, if it sat for awhile its clocked. same thing happened to me.

[SGA]

Try a new plug. If mine would pop and not start, I would change the plug (even though it looked fine) and it would run good for months. Just one of those things about a 400ex.

[csimp3]

i let mine sit for a month or so, and it ran perfect when i put it away, but when i pulled it out, just wouldnt start, so i changed the plug, and hooked it up to a jump box cause i killed the battery trying to start it, i had the choke on full and held the throttle down and held the start button for like 5 minutes, at first it just chugged and chugged but wouldnt start, finally it popped, smoked a bit, and then ran fine, but i had to give it tons of gas, also, make sure theres fresh gas in there

[honduh440]

my old 400 use to never start i had to get someone to pull me down the road and drop it in 2nd gear almost everytime. Also are you using the same gas that has been in it since it was last used?

[DieselBoy]

i added new fuel.....the new plug is wet, you can smell it....but it's acting as if the spark's inconsistant.... im gonna ruine the starter tryin to get this thing goin...

[SGA]

Originally posted by DieselBoy
i added new fuel.....the new plug is wet, you can smell it....but it's acting as if the spark's inconsistant.... im gonna ruine the starter tryin to get this thing goin...
New plug? as in a new one out of the box since you have had trouble starting it?

[250rinLV]

I think your problem is that its a 400ex you should sell it and buy a 250R!!!:devil:

lol i dont know anything about 4-strokes hope it turns out all right

[exrider008]

take the plug out and turn it over without the plug in it then put it back in and try that and if thet dont work then try getting a pull by a friend and pop start it.

[DieselBoy]

I was thinking about the tow-start, It might just work (i hope).
new plug out of box.

so with all the obvious/simple thing's asideI need to look closer at the electrical components. Possibly the spark is not consistant, a stator? i am not sure. this is where i need help with some electrical knowledge. I know nothing about these CDIs/Rectifiers.

[xx3003xrdrxx]

put it in fith and push it down a hill , once you get going dump the clutch , when it turns over pull in the clutch and give it gas , put it into nuetral and blip the throttle till its good and warm.

[DieselBoy]

Im gonna have to find an alternate location, our neighbors go NUTS if your SEEN on the road with one. Our whole area is full of psycho neighbors, up the road this kid stabbed his dad, another wife tried to stab her husband with a knife, another is on workers comp for life an he has NO disability and he evades taxes like its nothin tries to get me in trouble with the law all the time, everyone seems to have an anger problem...


i still doubt it's going to fire up though for some reason...

[exrider008]

Originally posted by DieselBoy
Im gonna have to find an alternate location, our neighbors go NUTS if your SEEN on the road with one. Our whole area is full of psycho neighbors, up the road this kid stabbed his dad, another wife tried to stab her husband with a knife, another is on workers comp for life an he has NO disability and he evades taxes like its nothin tries to get me in trouble with the law all the time, everyone seems to have an anger problem...


i still doubt it's going to fire up though for some reason...

sounds like u need to move.:eek2:

[EXevan91]

true dat, dont try and pop start it in fith... try pop starting it in 1st... good luck

[ryanh250ex]

you try cleaning the carb? my 250ex sat for a year, jump charged the battery, new plug, still wouldn't start. cleaned out the carb, stumbled and coughed to life.

[csimp3]

when your going to try to bump start or "pop" start, mechanics told me that 2nd gear is the best, just what ive heard

[Aceman]

Originally posted by csimp3
when your going to try to bump start or "pop" start, mechanics told me that 2nd gear is the best, just what ive heard

I would also try to pull start it, just to get it running. Don't listen to those guys telling you to start it in 1st or 5th:huh Always try 2nd first. If your tires skid, stand up and then sit down fast to put more weight on the rear. Try 3rd gear if the tires still skid.

[DieselBoy]

i'm pretty good with engines but when it comes to this electrical that i'm not familiar with I feel like such a dumbass, but I think it could be the stator. And I saw on some site it was $193 :eek2:

[exrider008]

just give pop starting it a try befor u start playing with it and spending a ton of money.

[DieselBoy]

i'll try it...does anyone have a picture of the left case off? I would just like a heads up and have an idea what's in there.

If you can it would be appreciated.

[sixer3]

nothin to it, just a flywheel and stator, unbolt and replace, i doubt its the stator, try spraying some ignition fluid into the intake tube while starting over, it does turn over right?....you could also try turning your crankshaft with a wrench like when your adjusting your valves, cuz i know you send when your cranking it, its and in-consistent crank, cranking with a wrench will tell you if the piston is siezed (possibility after rebuild?)

[exrider008]

Originally posted by DieselBoy
i'll try it...does anyone have a picture of the left case off? I would just like a heads up and have an idea what's in there.

If you can it would be appreciated.

go to this link and im sure ull find a pic. http://216.37.204.206/Mcmart/Honda_OEM/HondaATV.asp?Type=12&A=92

[DieselBoy]

wtf would cause the stator to go, on that site its $224.16 thats fing rediculous

[ryanh250ex]

try cleaning the carb, if the carb had any sort of gas in it it probably turned into varnish and this gummy chit, nasty stuff

[DieselBoy]

took the carb apart, blew out all the jets/canals... it's working good, float is free.

[DieselBoy]

its cursed

[werda400ex]

I always had those kind of problems, new plugs galore, i ran a NGK dpr8z plug for the past 3 years(recommended stock plug), but since this winter it wouldn't run on that kind of plug, so i went with a dpr7z and it started right up and ran great.........i really don't know why...........just my info

[DieselBoy]

it's just acting so weird. It's like pop......pop....pop.....it wants to go but something wont let it, it's a pain in the anus to figure out WHAT though. Never had anything like this.

[DieselBoy]

wow i think i'm at the point now where i just want to pour gas on it and burn it. i can't even work on it i get too pissed off at it

[rneal]

1) Charge your battery
2) Install a new spark plug
3) Do not touch the choke!!
4) While charger is still connected, crank the motor over about 10 revolutions.
5) Pump the throttle 3 times and try starting.

I have a 42 pilot jet and if I try to use the choke, it floods the motor.

[400exrider707]

Ok you still haven't said what upgrades or what exactly you did in this "rebuild" Give us some information here. Why is it that you think it is electrical? I had the exact same problem as your describing when I put mine back to stock and it was the decompression plunger (as in I forgot to put it back in) Need more info here!

[DieselBoy]

there's virtually no spark. the valves are set just right, it's getting fuel, fuels on, kill switch is free, new plug, new gas, battery charged well, throttle pumped, 416 piston & rings, rebored, new gasket's galore, stock cam, stock valves... no spark visible. i think it's the stator/pickup coil... it COULD be the decompression plunger, but it ran great after i finished putting it together, started like a dream, and one day it ran and just stopped, and hasn't run after that.

the only thing it will do is fire, not run. no matter where the choke is, the throttle, anything. the spark i'm guessing is inconsistant and weak, cause i sure can't see one when i ground it to the motor.

[RedneckYFZRida]

dude just go sumwere were some one can pull u and put it in 2nd gear and dump the clutch. just get pulled till it fires and if it dont get the dealer to work on it

[SGA]

Try using a small screwdriver or a piece of wire instead of the sparkplug to look at the spark. One end in the boot and the other about 1/4 inch away from the block. What kind of spark do you get?

[DieselBoy]

Originally posted by RedneckYFZRida
dude just go sumwere were some one can pull u and put it in 2nd gear and dump the clutch. just get pulled till it fires and if it dont get the dealer to work on it

dealer? HA...... they would be as puzzled as I am, they don't know bull. I don't wonna go in that deep - I'd rather just sell it for cheap.

[DieselBoy]

SGA - I'll try the screwdriver thing. I heard somewhere if you unplug the rectifier and you get spark, that's an indication your stator is bad, can anyone confirm this?

In all the pieces of sh.... i've owned I've yet to come across something like this. I've had the biggest piece's of sh.... running perfectly, and I've never seen anything like this in my entire life. This thing is truly cursed.

[CHEVYZ]

You need to go out and buy something to check your voltages. That would solve your problem right there. I did so and found the reason I had no spark to be my CDI. Yours could be the same, or it may be something different. I say just check it out and see.

[DieselBoy]

tried the multimeter in the wire going into the CDI from the stator, says 0.01 DC, but I dont know if that's correct. their saying 0.07, so i checked back near the battery, same thing. at one point it said 0.45 so i dunno

[400exrider707]

Ok its definitely not the decompression plunger at all, I didn't see anywhere before when you said that there was virtually no spark, sorry. Yeah electrical is not my thing, but there are quite a few members on here who know their stuff, somone should be able to make some suggestions. I would get in touch with wilkin250R he knows his crap. He's not overly familiar with 400ex engines, but engines in general. PM him and send him the link to the forum.

[PismoLocal]

So have you tried to pull start it or not?

[DieselBoy]

kind of...

[sixer3]

are you positive your getting compression?

[wilkin250r]

Originally posted by 400exrider707
I would get in touch with wilkin250R he knows his crap. He's not overly familiar with 400ex engines, but engines in general. PM him and send him the link to the forum.

The best suggestion I've seen yet! ;)

Get a multimeter and a service manual (not owners manual). It will give you electrical diagnostics. There's no way to test the CDI, but you can get a good indication of your stator.

If you're getting a "pop" now and then, try this. Get a new spark plug (yes, another new plug), and make sure your battery is fully charged. Take off your air filter, spray a little starting fluid or carb cleaner directly into your air boot, and try to start it immediately. Don't put your filter back on, because starting fluid will evaporate really fast. Don't pump the throttle, hold it about 1/4, and just see if the starting fluid gets a fire.

If it fires and dies, it's a fuel issue. If it doesn't fire at all, it's a spark issue. That starting fluid is really combustible, if you have any spark at all, it will fire. Like I said, do NOT pump the throttle, you don't want to add any extra fuel, but you also don't want the throttle completely closed. Spray the starting fluid directly down the boot, hold the throttle at 1/4, and crank it for about 5 seconds. Let me know what happens.

[DieselBoy]

Originally posted by DieselBoy
tried the multimeter in the wire going into the CDI from the stator, says 0.01 DC, but I dont know if that's correct. their saying 0.07, so i checked back near the battery, same thing. at one point it said 0.45 so i dunno

[wilkin250r]

A multi-meter on a DC setting won't give you anything. The signal coming from the stator is going to be an AC signal, but I don't even think the AC setting will give you an accurate reading, because it's not a true sinusoidal waveform.

If you have a peak-detection attachement, you would get a meaningful reading, but that's getting more advanced. Let's try some simple tests first, before you go buying new test equipment.

Did you try the starting fluid?

[SGA]

Well? Is it running?

[DieselBoy]

still workin' at it... haven't really had time, but i will be working on it tomorrow

[SGA]

How did it go? Did you find the problem?

[DieselBoy]

finally this weekend I will be swapping the stator & pickup coil, I will let you know then, I'm 80% sure this is the problem.

[Lamont400ex]

I have had this problem. First though has it kicked over and ran at all? do a carb clean. Pull her apart and juast tear it down and clean it all up. clean the plug right up and check to make sure you have no blockages in the fuel lines. fresh fuel is a must and then look at your kill switch make sure it is fouled at all. I have seen them get screwed up and cause no spark at all. Good luck

[DieselBoy]

i've completely disabled the kill switch, and I have ruled out fuel delivery, it will spark here and there, but the stator is my best guess. Spark is also weak when it does, and sparking is few and far between.

Stator's usually just quit without notice, and this seems to be what has happened.

[DieselBoy]

Going to get a stator saturday, god I hope this is the problem. I'm praying.

[wilkin250r]

Originally posted by DieselBoy
i've completely disabled the kill switch, and I have ruled out fuel delivery, it will spark here and there, but the stator is my best guess. Spark is also weak when it does, and sparking is few and far between.

Stator's usually just quit without notice, and this seems to be what has happened.

Did you get a manual and go through the electrical diagnostics? I can't imagine that you would spend hundreds of dollars on a new stator without spending a few bucks in diagnostics. It would be absurd for you to change the stator, and then find out the problem is the CDI.

[xc416ex]

I think you need to try to push start it. NOT! I had similar problems with my 400 but mine turned out to be a ground. If you don't have any luck with the new stator I will sit down and type you out a step by step to check everything from the battery to the plug. If you end up needing a recifier I have one laying around from my last bike and I can send it out to you cuz I don't really have any use for it. Good luck

[xtullyx16]

whats the news

[yfzfelix]

if its sat for a couple of months like you said I would think its the fuel, change it!!!

[DieselBoy]

waiting to hear back from Royal distributing about the stator for 231 (with tax). Until then, I'm going to pull all connections and check them over.

[DieselBoy]

Okay, apparently the stator cannot accurately be tested with an OHM meter according to this bike mechanic. He says they can both test the same, one may work, and the other may not. the only real way to know is to install one. I made some progress tonight and I've inspected everything I can think of and I'm stumped. I'm going to take the machine down to a guy I know in Bolton who runs a shop, and he has used 400ex parts, so he's going to test another stator in my machine, and we will see if that's the problem. It's beyond me now, I just don't know what else to check. Could it by Rectifier/CDI? I just don't know!

[wilkin250r]

That's sort of true, a stator that tests good still may not work. But if it tests BAD, then it's a pretty sure bet that it's bad.

Seriously, a multi-meter isn't all that expensive. Go through the electrical test. Even if you don't discover the problem, it's a terrific learning tool.

[DieselBoy]

wilkin- I tested the stator output from the rear fender and it read with the following results:

While it was turning over it read 0.00, the second you release the starter button it gave me the following results from the stator wires Blue/yellow with positive meter wire, and negative Dark Green (negative) at the rear near the battery. I tested up by the CDI plug with same results:

1. 0.05
2. 0.35
3. 0.07
4. 0.12
5. sometimes 0.00 (no reading)

It says the stator should read a minimum of 0.07 in the manual, but it jumps around, and when its cranking it doesn't really show any readings until the starter motor has been released...I'm confused.

What type of problems can a faulty CDI cause?

Any help is appreciated...

[DieselBoy]

I have also tested the coil with a 12v. battery and the spark appears strong using a screwdriver, when hooked up to the stator on the bike no spark is there.

[xc416ex]

I belive to test the stator you need a special meter that calculates peak voltage not actual voltage. i hooked up a meter to mine a while back and had the same readings but it wasn't my stator it was the ground to the cdi box. i ended up dropping it off at a shop and having them test it. good luck dude

[wilkin250r]

You need a manual to do a proper diagnostic. Trying to read a voltage won't do you any good.

I bet your readings are jumping all over the place, aren't they? That's because it's not a constant voltage coming out, it's a series of pulses, and your meter cannot react fast enough to read and display them accurately.

A manual should have the proper resistance readings for you to check. If the resistance measures good, it's a pretty sure bet the stator is good. It's only a few coils of wire, what could go wrong? They could melt together (which would have a low reading) or they could break (which would have a high reading).

Multi-meter. Manual. Turn to the electrical section and read up on the diagnostics. If you need help with your multi-meter, let me know and I can help you.

[DieselBoy]

I've done all the above and followed the Clymer's manual step by step, with a multimeter, but I'm going to take a chance and spend $126 on a new stator and hope for the best. There's no spark, so something is definately wrong with the stator, or, the pickup coil. I've already replaced the coil. And I don't think the CDI would cause no spark.

Also the way it's acted the spark wasn't right, and then the spark stopped working leading me to believe the stator was failing, and then eventually it did fail completely.

If this isn't it...I'm going to burn the machine to ashes and forget it. I don't know what else could be wrong.

My dad's a mechanic and he's had engines with faulty stators and he says they go without a sign. I'm eager to ride it, and I'm tired of screwing around with the electrical. I KNOW the coils working cause we tested the coil. Everything else is working fine, except this. I've even disabled the killswitch completely. The neutral switch works fine. The clutch switch works fine. the starter turns over fine also. Lights, etc. all work great.

[wilkin250r]

Don't give up TOO easily. I had a similar problem with a 250X. Sometimes it would start, sometimes it wouldn't. Sometimes it had a weak spark, sometimes no spark.

It turned out to be the CDI.

[DieselBoy]

Well if the CDI was junk, shouldn't it atleast run for even a sec? I mean, it's so weak it won't even kick more than once every now and then, it hasn't even thought about running even with fuel in the spark plug hole, and it is indeed getting fuel with a clean air filter. I've been told you cannot test a CDI. I just wish I knew someone nearby with a 400ex who could let me test their CDI on mine so I can rule it out....

I attempted to do a search for "CDI" but the forum doesn't allow any searches under 4 characters long.

[boricua]

dieselboy, i sent you a PM

[wilkin250r]

Honestly, this is coming from a guy that knows a thing or two about quads, and also knows a thing or twelve about electronics.

Try the CDI before you try the stator.

If you are going to take a chance and buy a new part, even if you don't know the exact problem, I'd spend that money on a CDI before a stator. I've just seen more CDIs go bad, and your symptoms sound just like mine.

A CDI is composed of complicated electronics. It takes energy from the exciter coils on the stator and stores it, then releases that energy when it gets a signal from the pulse coil on the flywheel. A lot can go wrong in that process. Your capacitor may be worn out, your terminals corroded, a bad electronic trigger, LOTS of things. The stator is just a couple coils of wire, not much to go wrong.

By the way, yes, a CDI could definitely cause a no spark. Or a weak spark. Or an intermittent spark. It could even cause all three in the same day, just depending on temperature. They're funny things, them little electronics.

[DieselBoy]

Okay I took it to the dealer for a diagnostics, and he says nothing is coming from the stator. He used the term exciter coil saying it needs replacing. What exactly is this? Is this the stator? I have to pick it up tomorrow, I still feel in the dark kind of. I'm going to replace the stator, and cross my fingers. I don't know why this is happening. I've spent alot of hours working on the motor and then this... I'm so fed up with this friggin thing... I've been to hell and back... I JUST WANT IT TO RUN! THAT'S ALL!

$165.00 with tax & shipping for a used stator/pickup coil.

The dealer is very sure it's the "exciter coil", I'll get more info when I talk with them in person.

Thanks for all your help, any further suggestions or info will be appreciated..............

[GPracer2500]

Yep, it's the stator.

The stator has a bunch of separate windings on it. Most of them create power for the charging system and lights but one of the windings is the "exciter coil". Its job is to generate the electricity used by the CDI and ignition coil to generate a spark at the plug.

In this picture (not a 400EX coil, BTW), the exciter coil is the black colored winding that looks a little different than the others.
http://www.brocktoncycle.com/images/ec0190/05-9122.jpg

If you were inclined to tackle such a project, I believe you could rewind the exciter coil on your existing stator yourself. It would cost less--probably a lot less. If you screwed up the rewind than all you're out is the additional cost of the wire, some epoxy, and your time. I might venture that the project would be worth trying just for the experience alone (if your into that kind of thing).

Or, look at it this way--this is the perfect opportunity to purchase that high output stator you've always wanted. You'll need a second voltage regulator also, but you'll end up with two circuits of 100w each (200w total) for running aftermarket lights. Your lookin' at maybe a little under $200 total (plus lights so you can use all that power).

http://www.rockymountainatv.com/RMATV-Images/productImages/160/E/ELE_REGULATOR.JPG
http://www.rockymountainatv.com/RMATV-Images/productImages/160/E/ELE_STATOR.JPG

I love night riding in the dunes and could really use more lighting.

[humblesquirel21]

im assuming you have but check all your wires make sure none of them have a c rack or break in them. my quad has done some really wierd stuff when one of the wires went bad

[wilkin250r]

Originally posted by DieselBoy
He used the term exciter coil saying it needs replacing. What exactly is this? Is this the stator?

Your stator isn't just one "part". It has three main aspects to it, lighting, exciter, and pulse.

The lighting coils are self explanatory, they produce electricity for your lights, and also to recharge your battery.

The exciter coil and pulse coil go to your ignition. Your spark doesn't run off the battery, it's completely independent.

The exciter coil produces a very high voltage (several hundred volts), and this voltage gets stored in your CDI. Then, that small bump on the outside of the flywheel passes the pulse trigger and sends a small pulse to the CDI. This pulse sets your ignition timing. When the CDI recieves that pulse, it releases all that energy it stored from the exciter coil and sends it through the ignition coil, which bumps the voltage from several hundred volts to several thousand volts. This is then fed to your spark plug and creates the actual "spark".

You can obviously see, if your exciter coil isn't working properly, you won't get a spark, because it's the one that actually provides the "energy" for the spark. The pulse is just a trigger, it doesn't have enough energy to actually create a spark.

[DieselBoy]

He plugged it into a diagnostics machine he has, and the stator produced nothing. He's 100% sure it's the stator, so, I'll be buying one ASAP, and I'll be back in the game.

Thank you very much for all the help.