CDI crapping out?

[Shift_450R]

Well I cased a jump and my 400 started bogging real bad at high RPMs. I took my carb out and cleaned everything. I changed my spark plug. The only thing i can think of is an electrical failure. Would my problem be a CDI going dead?

[DieselBoy]

did you figure out the problem yet? I'm in the same situation it wont fire or run

[Shift_450R]

Originally posted by DieselBoy
did you figure out the problem yet? I'm in the same situation it wont fire or run

no not yet. Mine fires and idles perfect just once i get on the gas it runs like a fat kid after running a mile.:ermm:

[DieselBoy]

If there's no spark, would it strike you as a stator problem? i've changed my coil and tested it with a 12v. battery.

[Shift_450R]

Originally posted by DieselBoy
If there's no spark, would it strike you as a stator problem? i've changed my coil and tested it with a 12v. battery.

lol i wouldnt have the slightest clue man.

[Shift_450R]

can someone please tell me if my CDI is burning out or what. Im getting ready to take the damn thing in and get it fixed.

[GPracer2500]

Originally posted by Shift_450R
can someone please tell me if my CDI is burning out or what. Im getting ready to take the damn thing in and get it fixed.

To my knowledge there is no way to test a CDI other than plugging in a known-good CDI and seeing if that eliminates the problem.

[Shift_450R]

Originally posted by GPracer2500
To my knowledge there is no way to test a CDI other than plugging in a known-good CDI and seeing if that eliminates the problem.
Yes, i know that but would the problems im having, would that be caused by the CDI? Thanks

[DieselBoy]

you know what, i've been thinking about it and for the $75 (1 hours labor) from the dealer it might be worth it to get them to tell you what's wrong, cause a stator/CDI is not exactly cheap.

[hondaracer31]

Check all of your electrical connections, especially the grounds. Also, make sure the terminals on the battery are tight.

[Shift_450R]

well, can take my quad and shake it like mad and it wont sputter or anything:huh

[hondaracer31]

That doesn't mean anything. My 440ex was running like crap, no power at high RPM, and it ended up being electrical connections. Another thing I've had happen is the spark plug boot getting loose on the coil wire. It is screwed onto the wire. Pull the boot off the plug and turn it to the right until it gets snug, just like tightening a screw. You might need to cut a little off of the coil wire to get some good wire. If you do this, pull the little black ring out of the yellow boot, then unscrew the boot off of the wire. After the boot is off the wire cut no more than 1/8th of an inch off the wire, and screw the boot back on then reinstall the black ring. The black ring seals water out of that connection and locks the boot onto the wire. If you look inside the wire end of the boot when it's off, you will see that it looks just like a sheet metal screw in there.
These are just my suggestions. I've never had a CDI go bad on any bike or quad I've owned, so I can't tell you what that would do.
Good luck and keep us posted.

[DieselBoy]

the symptoms your having sound like the CDI is faulty, however my situation seems more like a stator.

[Wildbrain]

Originally posted by Shift_450R
no not yet. Mine fires and idles perfect just once i get on the gas it runs like a fat kid after running a mile.:ermm:


Mine does the same thing. I'ts driving me nuts trying to figure out this one. It fires right up, idles fine. but about 1/2 throttle it statrs missing real bad. If you figure it out please let me know.

[curious george]

the solaniod on the spark plug might have broken or cracked making it skip at higher rpms. change the spark plug.

[DieselBoy]

its quite amazing what a faulty plug can cause. i've had a lawn tractor stop producing spark, and it turned out to be the plug. man what a relief.

[300ex_#387]

Mine is doing the same exact thing. Except its a 300. I will idle perfect and run fine, but when I get in the higher RPM's its just wont do it. I still cant figure it out. I'm with DieselBoy, im just going to pay the labor and have the shop look at it.

[Shift_450R]

Ok, i phoned the dealership and talked to the head mechanic and he told me to check the needle in the carb to see if the clip is broken. So im gonna rip the carb out tonight to see if thats the problem, im really hoping it is....its an easy fix

[300ex_#387]

Originally posted by Shift_450R
Ok, i phoned the dealership and talked to the head mechanic and he told me to check the needle in the carb to see if the clip is broken. So im gonna rip the carb out tonight to see if thats the problem, im really hoping it is....its an easy fix

I went through my carb already, and mine is doing EXACTLY what yours is. Let me know if that fixes it. I'm almost positive mine is electrical though.

[Shift_450R]

Originally posted by 300ex_#387
I went through my carb already, and mine is doing EXACTLY what yours is. Let me know if that fixes it. I'm almost positive mine is electrical though.

Ok i went through everything again and still no luck. I decided to take the f'ing thing in and let a professional deal with it.

[QuadJunkies]

A CDI doesnt just "go gradually" from what I have been told. When they are bad, they will just completly fail you and not a way to test them is another Ive been told.

hope they find your answer for you :)

[DieselBoy]

Originally posted by Shift_450R
Ok i went through everything again and still no luck. I decided to take the f'ing thing in and let a professional deal with it.

Frustrating, isn't it! let us know what it turns out to be. Good luck

[abuckley1290]

make sure your spark plug cap is tightly connected mine has been doing that too ( cutting at high rpms or WOT), and my plug cap was barely hanging on and wouldnt go on tight.. ordered a new one, just waiting for it to coem

[Shift_450R]

I figured it out....my fuel/air screw was way out, like 15 turns out:eek2: i adjusted it a lil bit better and it helped out alot. I can run WOT now and it just "hiccups" a little bit so i need to adjust it to where its perfect.

[GPracer2500]

Originally posted by Shift_450R
I figured it out....my fuel/air screw was way out, like 15 turns out:eek2: i adjusted it a lil bit better and it helped out alot. I can run WOT now and it just "hiccups" a little bit so i need to adjust it to where its perfect.

Hey, if it's fixed it's fixed, but...

I can't make any sense of your explination. 15 turns? The fuel screw should fall out at 15 turns--there aren't that many threads. Also, the fuel screw is part of the pilot circuit which has (practically) zero to do with WOT performance.

:confused:

[Wildbrain]

I guess that just shows there is not always a reason for things that happen. Glad to hear that your problem is taken care of. :D

[Shift_450R]

Originally posted by GPracer2500
Hey, if it's fixed it's fixed, but...

I can't make any sense of your explination. 15 turns? The fuel screw should fall out at 15 turns--there aren't that many threads. Also, the fuel screw is part of the pilot circuit which has (practically) zero to do with WOT performance.

:confused:

well maybe not 15 turns but it was damn near out. Ummm i cant explain why it helped but it did by alot

[GPracer2500]

Originally posted by Shift_450R
...i cant explain why it helped but it did by alot

That's what counts. Glad it's better.

[Shift_450R]

Originally posted by GPracer2500
That's what counts. Glad it's better.

It took a left turn. I think i have a burnt valve thats causing this. The motor gets very hot in a quick amount of riding and its over heating causing the bogs.