Honda Discussions about Honda ATVs.

400ex missing... (misfiring)

Thread Tools
 
Search this Thread
 
Old Nov 12, 2000 | 08:27 PM
  #1  
400exHUSTLA's Avatar
Thread Starter
|
Weekend Warrior
Joined: Nov 2000
Posts: 17
Likes: 0
Default

my 400 has been misfiring ever since i put on the wite bro's e-series...

Could the problem be with the copper crush gaskets that i didn't replace when moving around the headpipes to get the e-series to fit?

the jetting is perfect at a 5th gear cut off (light brown)

i can't feel any exhaust leaks....

It also POPS on decel.....

anyone wanna set me straight here?

thanks, later
 
Reply
Old Nov 12, 2000 | 08:48 PM
  #2  
400exalltheway's Avatar
Pro Rider
Joined: Mar 2000
Posts: 667
Likes: 0
Default

i had the same problems with my white bros. pipe. its a hard pipe to jet. whats your jetting set at? any type or airbox box? different filter. you could be running a little rich. let me know i probaly can help
 
Reply
Old Nov 12, 2000 | 08:58 PM
  #3  
01TRX400EX's Avatar
Trailblazer
Joined: Sep 2000
Posts: 65
Likes: 0
Default

when is it misfiring? wide open throttle? half throttle? It sounds to me like you have a jetting problem.....

Leo
 
Reply
Old Nov 12, 2000 | 09:31 PM
  #4  
Buckeye400EX's Avatar
Pro Rider
Joined: May 2000
Posts: 300
Likes: 0
Default

Did you get a White Bros, CDI box too? I've heard they've had problems with those too. Bad from the factory. ????
 
Reply
Old Nov 13, 2000 | 04:49 AM
  #5  
ATVAIR's Avatar
Trailblazer
Joined: Nov 1999
Posts: 59
Likes: 0
Default

What kind of problems have you heard?
 
Reply
Old Nov 13, 2000 | 04:36 PM
  #6  
400exHUSTLA's Avatar
Thread Starter
|
Weekend Warrior
Joined: Nov 2000
Posts: 17
Likes: 0
Default

I have misfiring problems at idle and low speeds..

it is jetted perfectly with a DYNOJET 170 main.. (brownish tint)

i am running 7 discks,(any more it runs to lean)
and a uni filter WITH the airbox lid.

i have no idea what could be up with it...

what are some of the factors that effect misifring besides jetting?
 
Reply
Old Nov 13, 2000 | 07:32 PM
  #7  
papaw's Avatar
Trailblazer
Joined: Nov 2000
Posts: 32
Likes: 0
Default

try richening the clip one step worked for my miss at quarter throttle.
 
Reply
Old Nov 13, 2000 | 07:52 PM
  #8  
400exHUSTLA's Avatar
Thread Starter
|
Weekend Warrior
Joined: Nov 2000
Posts: 17
Likes: 0
Default

this is a dynojet needle... is it still ok to do that?
 
Reply
Old Nov 13, 2000 | 10:44 PM
  #9  
papaw's Avatar
Trailblazer
Joined: Nov 2000
Posts: 32
Likes: 0
Default

IM NOT TO SURE ABOUT DYNOJET NEEDLES OR THE KITS FOR THAT MATTER BUT IF THEY HAVE CLIP POSITIONS IT WONT HURT TO TRY BECAUSE YOU ARE RICHENING THE MIXTURE.LET ME KNOW WHAT HAPPENS. 99EX K/N FILTER VENTED BOX LID STOKER SX1 SIL. WB REV KIT DG NERFS LSR PLUS ONE S/ARM RAZRS ON .190 ITP'S PRO TAPERS.
 
Reply
Old Nov 14, 2000 | 06:42 PM
  #10  
supra1641's Avatar
Trailblazer
Joined: Sep 2000
Posts: 33
Likes: 0
Default

Before you do anything else please just replace the exhaust gaskets. I had the same problem and it was because I didn't replace them. Just get new ones and fire them in, you should be good to go. PS: I felt no exhaust leaks either.
 
Reply



All times are GMT -5. The time now is 12:28 PM.