C.A.W.B
May 20 2006, 08:39 PM
I have an 04 kfx400. The other day it started running like crap out of nowhere. It would just fall on its face. I cleaned the carb and it still does this. The weird thing is it runs ok in the prime position.
To add to it I cannot get the idle to go up or down. It stays in the same place no matter how much you turn it. I have looked for vacuum leaks and cant find any. If anyone has any ideas the help would be appreciated. I am already jonsin to ride
banshee380
May 20 2006, 10:41 PM
QUOTE(C.A.W.B @ May 20 2006, 08:39 PM)
I have an 04 kfx400. The other day it started running like crap out of nowhere. It would just fall on its face. I cleaned the carb and it still does this. The weird thing is it runs ok in the prime position.
To add to it I cannot get the idle to go up or down. It stays in the same place no matter how much you turn it. I have looked for vacuum leaks and cant find any. If anyone has any ideas the help would be appreciated. I am already jonsin to ride
[right][snapback]1625495[/snapback][/right]
clean them filters
C.A.W.B
May 20 2006, 10:45 PM
QUOTE(banshee380 @ May 21 2006, 12:41 AM)
QUOTE(C.A.W.B @ May 20 2006, 08:39 PM)
I have an 04 kfx400. The other day it started running like crap out of nowhere. It would just fall on its face. I cleaned the carb and it still does this. The weird thing is it runs ok in the prime position.
To add to it I cannot get the idle to go up or down. It stays in the same place no matter how much you turn it. I have looked for vacuum leaks and cant find any. If anyone has any ideas the help would be appreciated. I am already jonsin to ride
[right][snapback]1625495[/snapback][/right]
clean them filters
[right][snapback]1625919[/snapback][/right]
I just did that after doing some reading on here. No change.
I also just installed a full yoshi system today noticed the headpipe is glowing after running for a few mins.
ChuckZilla
May 20 2006, 10:57 PM
If you didn't re-jet after adding the pipe then there's your problem. Did you leave your air box lid on? If so, then you're defeating the purpose of the pipe.
stugots
May 20 2006, 11:00 PM
QUOTE(C.A.W.B @ May 20 2006, 11:45 PM)
QUOTE(banshee380 @ May 21 2006, 12:41 AM)
QUOTE(C.A.W.B @ May 20 2006, 08:39 PM)
I have an 04 kfx400. The other day it started running like crap out of nowhere. It would just fall on its face. I cleaned the carb and it still does this. The weird thing is it runs ok in the prime position.
To add to it I cannot get the idle to go up or down. It stays in the same place no matter how much you turn it. I have looked for vacuum leaks and cant find any. If anyone has any ideas the help would be appreciated. I am already jonsin to ride
[right][snapback]1625495[/snapback][/right]
clean them filters
[right][snapback]1625919[/snapback][/right]
I just did that after doing some reading on here. No change.
I also just installed a full yoshi system today noticed the headpipe is glowing after running for a few mins.
[right][snapback]1625924[/snapback][/right]
You have to re-jet it after the Mod you just made.
Faten up your main jet to get more fuel for the the air flow you just added .
While your at it do some work on your air box and filter so the motor can breath right.
stugots
May 20 2006, 11:02 PM
QUOTE(C.A.W.B @ May 20 2006, 09:39 PM)
I have an 04 kfx400. The other day it started running like crap out of nowhere. It would just fall on its face. I cleaned the carb and it still does this. The weird thing is it runs ok in the prime position.
To add to it I cannot get the idle to go up or down. It stays in the same place no matter how much you turn it. I have looked for vacuum leaks and cant find any. If anyone has any ideas the help would be appreciated. I am already jonsin to ride
[right][snapback]1625495[/snapback][/right]
How did you clean the carb?
You realy have to make sure that nothing is cloged double check every passage.
Blow through everything with carb cleaner then air.
nosocks
May 20 2006, 11:04 PM
what did you do to the carb after the install of the system?
Has it sat at all longer than a month?
Did you go through cleaning all the jets in detail?
does it start popping like mad when running?
Have you added gas recently? Specifically gas from a mom and pop place?
C.A.W.B
May 20 2006, 11:17 PM
I Have an open air box with k&n. I put in a 150 jet per yoshimura. It is backfiring.
The carb problem just came out of nowhere 2 weeks ago. I actually bought a different carb from a friend which I know was in good shape and no change. It still runs fine in prime and not in on. And the idle wont adjust. I would like to fix that problem first then figure out the exhaust. This problem happened before the yoshi install.
nosocks
May 20 2006, 11:27 PM
Let me guess, the backfiring occurs when you rev and let off? If so, you need to up the idle jet. Don't know what the setting would be for a KFX as I don't own one, but my YFZ had the same issue even though I took the manufactures advice.
BeachHead
May 21 2006, 06:40 AM
Regarding the need to run in prime position, check your gas cap. These have a vacuum activated delivery system, and I had an 03 that the center part of the gas cap actually broke, and it no longer sealed, so no vacuum, no gas. It had very similar symptoms. Or possibly look at the supply side to the carb for loose, cracked hoses, etc.
Oldman
May 21 2006, 07:05 AM
If the bike will run in the prime position, sometimes the petcock is bag. In the prime position you bypass the vaccum operated part of the petcock. This is a common problem on the Suzuki's with this set up. The LT80's are really bad about this.
SHOCKER
May 21 2006, 02:13 PM
Is the vaccum hose connected to the petcock?
Mac
May 21 2006, 06:54 PM
Petcock is what I was thinking...
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