smelly$cat
11-12-2006, 10:48 PM
I recently purchased a 02 400ex.
It ran pretty good the first time I took it out for some woods riding.
The second time I took it out, we took it to the dunes and at the end of the day, it started running poorly. The symptom was mostly gutless performance when the rpm's were in the mid to high range. Since it was the end of the day, we just packed it up and took it home.
A few weeks later, I started investigating. The first thing I noticed was that the big tube from the air box to the carb had come disconnected partially from the carb side. I thought that maybe this was the cause since maybe it was getting too much air. However, after putting the tube back in place, it made no difference.
I've done quite a few things at this point to troubleshoot this problem. But, the bike is still running very bad.
This is what I have done to try to solve the problem so far.
*Cleaned the air filter
*Replaced the spark plug (NGK from dealer)
*Cleaned carb with carb cleaner (removed the carb and cleaned the float bowl, removed the main jet and cleaned it (didn't find much, just a little gunk on the tiny side holes on the jet).
Re-assembled.
The symptom is still more or less the same.
When the bike it cold, it will start right up with the choke full on. It will run for a little while this way. But, after a short while (1 minute), the bike seems to choke itself and it dies. At this point, I cannot start the bike regardless of where the choke is set.
Once the bike starts with the choke on, I've tried turning the choke off and just trying to keep it running with the throttle, but it pops and sputters quite a bit and eventually dies.
I've tried starting it, shutting off the choke and riding it immediately and the same thing happens. For short spurts, it pulls hard and rides great, then it burps pops farts and starts to stall out until it fully stalls. Again, I won't be able to start it up at this point with out wating a little while (couple minutes).
I've read some posts on here that it might be related to the gas cap, so I've tried to keep it running with the cap off and that didn't work either.
My gut tells me that it's flooding itself some how. But, I'm not sure what to do to fix this.
I'm wondering if some sand may have gotten somewhere it shouldn't have when the tube came loose from the carb at the dunes. Maybe it's causing the float to stick or something.
What do you guys think? I'm open to ideas at this point. I want to go riding again...
Thanks in advance!
-Jeff
It ran pretty good the first time I took it out for some woods riding.
The second time I took it out, we took it to the dunes and at the end of the day, it started running poorly. The symptom was mostly gutless performance when the rpm's were in the mid to high range. Since it was the end of the day, we just packed it up and took it home.
A few weeks later, I started investigating. The first thing I noticed was that the big tube from the air box to the carb had come disconnected partially from the carb side. I thought that maybe this was the cause since maybe it was getting too much air. However, after putting the tube back in place, it made no difference.
I've done quite a few things at this point to troubleshoot this problem. But, the bike is still running very bad.
This is what I have done to try to solve the problem so far.
*Cleaned the air filter
*Replaced the spark plug (NGK from dealer)
*Cleaned carb with carb cleaner (removed the carb and cleaned the float bowl, removed the main jet and cleaned it (didn't find much, just a little gunk on the tiny side holes on the jet).
Re-assembled.
The symptom is still more or less the same.
When the bike it cold, it will start right up with the choke full on. It will run for a little while this way. But, after a short while (1 minute), the bike seems to choke itself and it dies. At this point, I cannot start the bike regardless of where the choke is set.
Once the bike starts with the choke on, I've tried turning the choke off and just trying to keep it running with the throttle, but it pops and sputters quite a bit and eventually dies.
I've tried starting it, shutting off the choke and riding it immediately and the same thing happens. For short spurts, it pulls hard and rides great, then it burps pops farts and starts to stall out until it fully stalls. Again, I won't be able to start it up at this point with out wating a little while (couple minutes).
I've read some posts on here that it might be related to the gas cap, so I've tried to keep it running with the cap off and that didn't work either.
My gut tells me that it's flooding itself some how. But, I'm not sure what to do to fix this.
I'm wondering if some sand may have gotten somewhere it shouldn't have when the tube came loose from the carb at the dunes. Maybe it's causing the float to stick or something.
What do you guys think? I'm open to ideas at this point. I want to go riding again...
Thanks in advance!
-Jeff