wont start please help

[abuckley1290]

I have a 03 z400 thats been great no problems. A few months ago i started it, ran perfect, turned it off and trailered it to my house. It sat over ngiht adn then when i went to go riding the next day it would not start at all. While tryin to jumpstart it with another quad it sounded like my xr100 did when u try to jump start it with no key (low bogging noise from no spark). It sat for a while and i finnaly recharged the battery and changed the sparkplug, but still no luck. I have no idea where to start and what to look for???

[z rider2]

hey man, from the sounds of it it could be 1 of 2 things... you may need a new battery. i went through this awhile ago. even though i jump started it with another quad, the weak batt, ate up enough juice that it wouldnt turn the engine over fast enough. the other thing is your valves may be out of spec. the stock valves tend to tighten over time causing hard starts and eventually break, does the motor turn over fine? or is it just not starting?

[jonboy]

Is it cranking over? If it is try putting the petcock on prime and make sure that your gas cap vent is working. How old is the gas?

[abuckley1290]

the motor turns over fine and ive tried all the petcock positions...the thing is idont have the manual to do a valve check and really dont wanna mess anything up and would the aftermarket valvesprings make a difference in required clearence?

[z rider2]

well, if it cranks over fine it could be the valves, or try putting your stock ignition back in. i've heard of the cheaper (made by Procom) rev boxes cutting out, and not putting out any spark. if u need help checking your valves PM me and i'll walk u through it.

[the fat kid]

well ive got something similar but mine usually starts, its just barley turning over for a couple minuets it seems like, and itll start, but if im in the middle of riding, it cranks right up like no problems, i put a volt meter on it and it says 11.9 volts, so i suspect a bad battery but then again it wont go dead ever, idk sorry if this seems like thread jacking but i didnt know if you had something similar to this going on, im leading towards a bad cell in the battery or bad battery overall

[abuckley1290]

i also just figured out that the throttle istn returning properly and when you give it WOT while trying to start it, it doesnt sound deeper like it normally would...maybe its not getting gas?

[drzoo2]

Here is a quote from my good buddy CFM-Z440 0ver at central

z


Here is a previously prepared statement I have come up with to answer the Question, "Why wont my Z400 start?" Because when they cup a valve, they will run like crap then after a little longer, they will die, and wont start...

Check your valve clearance. My guess is that you will find 0 clearance on at least one intake valve, meaning it is cupped and the valve is junk.

This is a common issue with the Z especially lately. The stock valves in the Z400 engine are not very good and dusty conditions dont help either. Dust is like a sand blaster on your valves. If you havent cleaned your air filter often enough, that could be the cause.

If you find 0 clearance, you can Not reshim and go. The valve is ruined!
The best fix is Kibble White "black diamond" stainless steel valves. I wouldnt do it without DRZE springs, and a DID timing chain. Those are the weak points of the z400 engine and if you have it apart any way, it is a good idea to get that stuff changed.

You can get them all from Advantage Cycle (site sponcer) He sells it as a DRZe kit, but I believe the valves are seperate. It also comes with a DRze base gasket that will raise your compression and make a little more power. You will need to run premium fuel if you put that base gasket in though.

I have been through this my self with my 03, and I have helped many other people with this problem on this forum.

[dan42684]

the same thing happen to me. i was riding for a few hours, loaded it on my trailer and when i got home i went to start it and it would not start it tried to start but wouldnt. so i let it sit over night the next day i had my brother pull me with his car. he pulled me around for about 2 minutes before it finally popped started i think i was in 2nd gear when it turned over.

[the fat kid]

so just so i can eliminate me thinking that this is whats happening to mine, if this were a problem with my bike it wouldnt start at all, not even crank?

[planoatv]

Chect the spark plug my z400 did this and the plug hole was full of mud!!!! shorting out the spark plug:rolleyes:

[atvchik]

same thing just happened to me after the bike had sat for awhile.
it wouldn't start...just cranked and cranked.

i checked through all mech/elect with no luck of finding any problems, come to find out....the automatic decompression device needed more force to open the exhaust valve.....in short....a push start down the driveway started it right up. runs great now.

it happens to alot of Z/KFX 400 riders.
you can do a search on Z400Central and read several posts with the same result~