that is a tough one. i have a 2003 z and when it was stock i found that it would stall on idle for some wierd reason also but not so bad that it would bother me so much when i am on the trails. The only time i found it was a pain was off the line when i would give it a quick shot of gas it would die. After i put my fmf pipe and k&n filter on and rejet it, it ran PERFECT! but that is what my problem was, i know if your valves get to far out of set it will be extremely hard to start, i had an old yamaha that the valves were burned and they told me there was no way it could have started but for some reason it would start but it didnt start good, it too didnt idle very good. it is not hard to check if your valves are out of set, i believe thier is a pretty big thread on it in the pinned section. I havent heard of valves failing on a stock bike with a stock cdi, it is more common on the bikes that have the high rev cdi's, search for meade377's build (not sure what section it is in) and you will know what i meen.

The stock valves are a 2 piece design which have been known to break at extremely high rpm.

hope this helps.

 

if it pops on decel and runs lean at idal then go up in you pilot jet

 

QUOTE (z400motocross @ Dec 29 2007, 03:19 PM) index.php?act=findpost&pid=645291

if it pops on decel and runs lean at idal then go up in you pilot jet[/b]

but he was saying that it was running fine before he stored it. the only thing i can think of on the carb (since you cleaned it before you rode it) is that maybe you didnt set the fuel screw proper. but i doubt it if you brought it to the shop to get it looked at they should have checked that.

 

Thanks but still the same
The mechanic told me a posible burned valve ,
but i don't notice any hard to start
hope some one knows whats going on
I think the mechanic its just guessing what's wrong
don't Know what to do

 

did you so the simple first? drain all gas and put fresh gas in it? maybe water/moiture in the gas...

 

yep bad gas could really mess up your carb also. having run into burned valves on my other bike i seriously doubt that it is valves, according to your explanation of the problem.

 

I did ride ,,,,,,,,,,,2 full tanks of gas already
but i never drain the old gas
was just a little bit of the old gas I just fill it with new an ride it

i did check again starts right up even when its cold (just with the choke on)

but still the same problem for some reason i dont think is any burned valve

THANKS everybody for your comments

 

so its running good now?

 

QUOTE (rumlesj1 @ Dec 31 2007, 01:15 AM) index.php?act=findpost&pid=645538

so its running good now?[/b]

NO still stalll at idle

 

maybe you should clean the air filter? check the vacume lines going to the carb. if it was me, i would clean the carb one more time, make sure everything is hooked up and installed right inside the carb and out. Clean the air filter, new spark plug, and new gas before you even turn the engine over again. Check and make sure the petcock is clean they gum up to ya know.

 

it wouldnt hurt to clean your carb completely again, make sure that your fuel screw is to spec and your needle is on the right clip etc. did you try turning your idle screw up a bit??

 

QUOTE (rumlesj1 @ Jan 1 2008, 12:48 AM) index.php?act=findpost&pid=645810

it wouldnt hurt to clean your carb completely again, make sure that your fuel screw is to spec and your needle is on the right clip etc. did you try turning your idle screw up a bit??[/b]

Yes , I did try to turn it up the idle screw, an yes stay at idle a little longer but every 6 or so seconds sounds like its going to stop running and pops a lot more on deceleration





keep your opinions comming please
Thanks again

 

I realize this a very old thread but was this ever solved I am having the exact same symptoms that you are describing on my 400

 

that's a pretty vague statement but I would start off by cleaning your pilot jet.