Hey guys, I have a 99 400ex witha 440, race cam, race carb, and high comp. piston, and it won't start right now. When I tried to start it last was about a month ago (the night before I left the country for a month), and I havn't really been able to check anything on it, so I don't know really any reasons for it acting up at all. Whne I tried to start it, it had sat for about a month and a half, but it has sat much longer in the past and never had any problems. I run 101 octane gas in it, and it had an almost full tank. Fuel was of course turned on, and everything should have been right. It jsut turns over and over and over, but just won't catch. Every few tries to start it, it would make a big pop sound (kinda like a backfire) out of the exhaust, but I'm assuming that it was just some of the fuel that isn't being burnt up combusting in the exhaust (I could difenatley be wrong aboutthat though!) Anyway, I'd appreicaite any ideas you guys have for me! When I get back home I'm gonna try changing out the spark plug, but other than that Idon't really have any ideas yet! Thanks a lot for any advice you may have!

 

gottta be the spark plug or the carb float is stuck

 

yea man that prob. the spark plug. change it defintaly also if u want just give it a SMALL SHOT of either. im talkin just a small mist, just enough to give some juice.

 

I just want to clarify, you quad has been running great and now you let it sit and your having this problem? I wasn't sure whether this problem started before you left or not? Let us know how the spark plug goes. And if that doesn't work be sure to note what condition the spark plug was in. I have got to ask this so don't rip at me, but is your kill switch in the run position?

 

maybe it might be the cdi check that.

 

Hey, thanks guys. I won't be back home untill the 10th of december, but I'll switch out that plug when I get back and let you all know how it goes. yes, the kill switch was in teh run pos., the key on, the gas on, and the carb adjusted. I checked and re-checked all those things, just to be sure that I wouldn't make a post like this, and then have to admit that I'd forgotten! Anyway, thanks again! Oh yah, the quad was running perfect, and then just wouldn't start.

 

99% of the time its the plug. mine went bad on a 30 min drive to go ride. it started fine when i went to load it. when i unloaded it...it wouldnt start to save my life. ALWAYS have a spare plug in the tool kit!

 

yeah, does sound like the spark plug

 

Hey guys,
I just got home yesterday, and today I tried putting a new spark plug in, and it still won't start. I took the intake off and had a peek at the carb and it looked fine, the butterfly is oppeing up fine, and seems to be in working order. Next I'm gonna pull the plug back out and check to see if it's getting spark. Any other ideas is much appreciated! I've had this up for sale for a few months, and I just got a person that wants it, but I've gotta get it running first! Thanks a bunch guys!

 

Is the carb shooting fuel into the intake when you press on the throttle?