Sign in to follow this  
Followers 0
Kfxrider90

Suzuki
KFX 400 Dies when throttle touched only will idle with choke

10 posts in this topic

Background:

06 kfx 440

Jetted perfectly on stock 06 carb

Hotcams

Big Gun CDI Rev Box

LRD Full Exhaust

Has about 200 hrs on this setup.

Oil changed regularly.

Has a fresh oil change with 10 min of idling on it. (come to think of it before changing it it seemed to die after a few min of idling to warm up, but I thought nothing of it and changed the oil.)

Sat for 2 months without being ridden, but ran perfectly when parked originally about a week before the oil change. Went to pismo and it would not run after a 9 hour drive to the dunes . Spent the weekend trying to fix things with no improvement. Before I left the bike ran sluggish, but ran enough to load it.(MISTAKE) #1 Needed choke though.

Symptoms

The bike will turn on and idle normally with choke on about 1/2- full choke for about 3-4 min then die on its own, but the second I even touch the throttle even a hair it instantly dies. No matter if on prime, reserve or on.

91 octane gas is still old and I did not use sta-bil. Wouldn't it not even start if the gas was totally horrible?

What I've done so far

-Cleaned the main jet and pilot jet with carb cleaner. You can see daylight through the holes. Even before cleaning everything looked new. Float did not seem stuck at all.

-Unplugged CDI and plugged back in

-Grounds are on tight.

-The little wire near the throttle is plugged in (not sure what it is even)

-All hoses are attached to the carb. Including the air box and hose from intake port to carb.

-I blew air through the petcock tube into the tank using the healthy choice of using my lungs. Gas flow didn't seem like a river coming out of tube, but about a stream.

-Even tried starting with gas cap off. No difference.

What do you think I can do? I'm so lost and frustrated. I've had 0 problems with this quad until now.

My k&N filter seems a bit dirty though, but I don't think its enough to make it not run.

Share this post


Link to post
Share on other sites

Basically same problem going on at my property right now. My 06 Kfx 400 is all stock though. Starts right up every time idles perfect ..... soon as you give it gas it will respond a little then quickly die. If i cant figure something out, I'm gonna have to scratch the shit out of my truck to get it lol. Has ran perfect till this point very low hours. Any ideas?

Also I see that his quad runs and idles with choke..... my is the opposite. If i pull the choke down it dies.

Share this post


Link to post
Share on other sites

VERY common and easy to fix issue.

I cant tell you how many times I've fixed this exact problem as our riding group mechanic.

Carb cleaner does not get the crap out of the jets the way you think it does.

1. Go buy a cheap set of guitar strings.

2. Cut them down to a managable length and add them to your tool box.

3. Pull those same jets out and wet them with carb cleaner and run the strings through the jets. Start with the smallest and work up to the largest that will fit through.

4. Put it together and ride on.

Never fails for me and the symptoms are exactly what I see and what goes away afterwards.

Share this post


Link to post
Share on other sites

KFXrider 90:

Here is where things went wrong:

"Sat for 2 months without being ridden, but "

Save yourself the trouble and spend the $2-3 at home depot for some tubing and make a little jig to drain the bowl anytime the bike is going to sit.

Share this post


Link to post
Share on other sites

Well I put the OEM CDI in and no difference. I then took off my gas tank to see if there is spark. There is a lot of spark with the OEM CDI and Big Gun CDI. The one thing I noticed was that my spark plug seemed very black. I'm going to purchase a new one since it is about 2 years old.

Any suggestions?

Share this post


Link to post
Share on other sites

So removed carb and did thorough inspection. Found gigantic gas booger hiding in the main jet. Cleaned everything, set float and buttoned everything up. Runs like a champ. :thumbsup:

Share this post


Link to post
Share on other sites

UPDATE

Today I cleaned the carb really good. I found some corrosion inside my carb, but it came off easy with cleaner. Took out all the jets and cleaned them as well as the needle and float. Basically if it can come off I took it off and cleaned it. I also cleaned the sparkplug and checked the gap (it was perfect) I also cleaned out the fuel filter.

So now atleast I can get it to start( last week it wouldnt even do that) for about 20-30 seconds even without choke which is a plus. The bike still instantly dies even with the ever so slightest touch of the throttle.

I'm lost help!!!

Share this post


Link to post
Share on other sites

Yes I did.three times now taking the entire thing apart. Weird thing is using the tiniest amount of startting fluid it would run and the throttle would work for about 10 seconds.

Share this post


Link to post
Share on other sites

Default

OK new UPDATE 2/12/11

Got a used carb and installed it it started for a second and thats it.

So i did a compression check (cold) and I got 95lbs....yikes!!! I then decided to check my valve clearance(while cold) and I couldn't even get a .08 feeler gauge under the intake or exhaust. I'm not sure how much of a difference if it was warm it would make.

BTW- i didn't find any metal flakes or anything.

Ideas?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Similar Content

    • By WVAikman
      2008 Suzuki DRZ400S for sale.  $3300 (negotiable).  New tires, Tusk bar protectors, Full rack system - rear and sides, Contour Carmichael bars w/ProTaper riser.  5257 original miles.
    • By Garage49
      Hey there,
      I recently bought a 1979 Suzuki PE250 in pretty good condition for its age I'd say.However the fork seals are leaking and after struggling for a few days to get the fork caps open(they were seized) I have now come to a new problem.
      The Dust seal Holder seems to be stuck, in the shop manual it mentions some sort of special tool for removing the fork seal but I'm not sure what exactly it would do.The thing seems like it should just unscrew. I've tried whacking it with a screw driver and a hammer and I had some minor progress but its painfully slow so I was wondering if any of you vintage motorcycle wizards would be able to enlighten me.
      Any help would be greatly appreciated.



    • By iamoto264
      Hello all here goes my first post,
      I have a fully rebuilt rmz 450. The bike runs great, the only problem is every time I try to kick the bike over, about every other kick the bike gets hung up, like some of the teeth on the kick starter gear or the idler gear or clutch basket are messed up. I tap on the kickstarter and have to lean the bike over a bit and keep tapping the kick starter and then it will free up for a few kicks. I took the inner clutch cover off and swapped the kickstarter gear with the one that was in it because I had one laying around. Worked for about two rides, then same thing. I found quite a bit of black suit looking stuff that appeared to be from the clutch plates like it was possibly getting in between gears and causing them to bind. However, I just received a new washer/spring that goes behind the idle gear and wondering if that could be the issue.... Again, I have rebuilt a ton of motorcycle engines and am very knowledgeable, but this just baffles me because I haven't found any damage to the gears from the kickstarter, idle gear, and clutch basket. Any advise would be great. I have attached pictures of the washer and I believe the manual calls for the convex side facing inward. 

    • By VintageMoto
      Hey all,
      Im looking to update the suspension on my 1985 RM125 because it is insanely soft for me. I'm only a 150 lb rider so this leads me to believe that something is wrong. 
      I'm not experienced with suspension work so I don't know what would cause this. 
      I am also looking into an inverted fork swap and I was hoping that someone might know what triple clamps would fit my bike or what inverted forks would fit my stock triple clamps. 
      All help/advice is appreciated, thanks!
    • By Myles D
      What's up guys. This is my first question I've posted on here; I need some help. I recently bought a 2001 RM125 to fix as my senior project, expecting to be putting a top end in it and cleaning it up. Upon further inspection, the entire top end was shot, and when I took the cylinder off, I saw moisture and rust on the crank. Fast forward a few months and I have purchased a full top and bottom end and installed both. I put the bike engine in the bike today to see if I could start it and the kickstarter is stuck. I know the top end is not seized because I can hear the piston moving when I spin the clutch. Any ideas?