Hey guys,

I went in halves with a buddy of mine on a 2000 400ex a few months back, but I don't know a damn thing about them. I'm fairly new to atv's in general, but I would rather try to tear into this thing myself instead of paying somebody else to do it.

Here is the deal...the guy we bought it from told us it had some work done such as the 440 kit, white bros exhaust, jetted, and new filter. Now we can obviously see that it has the exhaust and filter....but how can we tell if it really has the 440 kit or not? He wasn't the one who had the work done, he bought it as I described it...so we really cant go back to him and ask about it.

Now for the problems.....

There was a little gas leaking around the carb ever since we got it, but I figured that was just because the carb was loose, I tightened it all up the first day I had it and I thought that took care of it. After looking at it a few more times, I saw that it was still leaking from somewhere.
Also, we had it out at the dunes a few months back, and it ran fine. After we got it home, I put it straight into my shed and didn't touch it until last week. I pulled it out, and fired it up....it started like normal, but died after about 20 seconds, and now it wont start.

I played with it for a while today, but didn't want to get too deep into it until I get my wolverine put back together...the last thing I need is two machines all tore apart in my garage, I will never get them back together! lol

Anyway, when I hit the start button, it cranks over like normal, but it wont start...not even a sputter. If you hit the gas a little while cranking it, you can hear it making a sucking noise, but I cant smell any gas. Even if you hold the throttle wide open, no gas smell......

Sorry for being so ignorant on these things, but like I said...I'm pretty new to them. I have never touched a carb other than when I tightened it up when we first got it....so it may be a little challenge to take it apart.

Anybody have any ideas or suggestions? I'm sure it could be a million different things, and I'm probably not describing it very well, so if you guys could just point me in any general direction I would really appreciate it.

Thanks,

Kyle

 

you probably leaked all your gas out, try putting some new gas in it and turn the fuel valve onto "reserve".

 

There is plenty of gas in it, and I have tried reserve and on normal....Im thinking the carb may need rebuilt or just cleaned out.

 

How many months did it sit?

 

about 2 months. Are you thinking bad fuel?

 

Yah, but nm.. Mine have sat a lot longer than that and still run just fine.

 

Of course you have to have three things to run, fuel, spark at the right time, and compression. Well, it seems you have looked in the tank and there is fuel, so take the plus out and check for spark, while the plug is out check compression. If it has spark and compression, I would have a look at the carb. If it sat for 2 months it could have gummed up, I have saw it happen quicker than that before.

One more thing that you might want to do first. You said it ran for about 20 seconds, that about what would have been left in the bowl. with your fuel valve on open the carb bowl drain screw and see if fuel flows. If not, you will find a stuck float most likely.

 

Hi ya,

If you're new to the 400ex you may want to consider this.

I know with mine, when I initially start it when it's cold I have to close the choke completely, pump the throttle once, then just barely crack the throttle (like 1/32 open) then turn it over and it'll fire up instantly. If I use more than 1/16 or 1/8 throttle during initial start of the day it will flood out.

After mine fires up when it's cold I'll put it in gear and let it ride around just above idle speed and I'll completely open the choke once it's underway. After it warms up, maybe a couple of minutes, it's good to go for the rest of the day. It's actually difficult to hit the starter button and not have it fire up.

I also know this, if it starts and runs briefly (within the 20 second zone as in your case) it can be difficult to start. I know if I had done what you did mine would have flooded out. When flooded common sense says to open the choke and use the full throttle position and turn the engine over...........that never work(s) for mine.

Anyhow, just food for thought, I know all of this is case-specific to my 400 but maybe yours in comperable.

Good luck!

Brian

 

Also, this spring after mine had been sitting all winter, I went to start mine up and flooded it out. I cranked on it for a bit but then decided to pull start it w/a tow strap and another vehicle. I think I used second gear and didn't go terribly fast w/the tow vehicle.

I wanted to get a lot of air though the cylinder to dry out the combustion chamber and it took a whild but if finally fired up. I thought this was easier on the starter, battery, etc........

 

I just got it running!

I started digging into it a little bit today because Im waiting on parts to arrive for my wolverine, so Im not devoting all of my spare time to that anymore.

First I pulled the plug out, then tried to start it with no plug in just to make sure I could smell the fuel (which I could), so the fuel supply out of the question. Then I cleaned the plug up and touched it against the frame while trying to start it to make sure I was getting a spark, which I was.

I figured it was probably flooded again, so I didnt want to put the plug back in and try again just yet...so I let it sit for about a half hour, and then blew compressed air into the spark plug hole just to make sure it was dry.

After that, I put the plug back in and used b88miller's starting technique and it worked like a charm. As soon as I touched the starter it started to try and turn over and chug a litte, which it hadnt done ever since it stalled a few weeks back. I tried it again with a little more throttle, and it started perfectly and ran for a minute or so until I turned it off.


I wonder if cleaning the plug up did it (because it was full of carbon), or if I was just flooding every time, but I doubt it was the flooding because it never even attempted to start like it did after I cleaned the plug.

Oh well, as long as it runs Im happy.

thanks for all the tips and suggestions guys!

Now does anybody have any idea on the wiseco 440 kit? Any easy way to tell without tearing the motor apart?