400ex wont start. Advice needed

[nakomis0]

Well this is the first time ever I have had a problem with this quad. It has sat for about a yr. Although I did have it started and it ran just a few months ago. I rode it down the block only.

I recently did work on it. I had to remove the cam chain tensioner and re install it. This was due to a broken bolt. I don't think that would cause a problem.

I also installed a new throttle cable. That should be a no problem install.

And I did notice the large valve cover bolts where real loose, the ones you would remove to adjust the valves. I probably road it with those on that little run down my street.

I just don't see any of those things causing an issue. But wanted to list the changes I did...

I have fresh gas and a new spark plug. I also swapped the CDI.

What its doing is, it will start for about 1 second and then die. It seems to die immediatly after I let go of the start button.

I tested spark and it has spark when I'm holding the start button.

Fuel, .. seems to have fuel... I know fuel is getting into the carb and atleast to the bowl.

I need advice what should I test? What could it be? Any help would be great. Thank you.

[GRASSHOPPER71]

IF IT'S BEEN SITTIN UP FOR A YEAR,, PROLLY NEED TO CLEAN THE CARB GOOD AND PUT IT BACK ON AND SEE WHAT HAPPENS. IT SHOULD BUST RIGHT OFF WHEN YOU GET THAT DONE,, IF NOT COME BACK AND LET US KNOW AND WE'LL GO TO ANOTHER STEP.

[GPracer2500]

Yup. Clean the carb. Chances are excellent that is the problem. Even if it's not, eventually you'll need to cross the carb of the list of possible suspects anyway.

[bigbad400]

did you try to choke the chit out of it and make sure your plug is getting gas? the boys are right, clean your carb and then let us know.

[nakomis0]

Well I found the problem!

Let me tell ya, I went through this whole bike. Checked and adjusted the following...

Exhaust
Cam chain
Cam chain tensioner
Valve clearances
CDI swap out
All wiring
Changed the gas
Cleaned the carb
thread seal on the carb threads
Clean all the carb jets
New plug

Still it didn't work! I look in the carb like I have done about 10 times before and notice something.... Something looks or is acting kind of weird about the needle.

Upon inspection it turns out the clip on the needle came off. So the needle was just sitting on the main jet not letting any fuel in. :rolleyes:

I put about 8 hours into this thing just going through it trying to find the problem, (cleaning as I went). Atleast shes allot cleaner and I know everything is adjusted and looks good.

Can't believe I missed that so many times.