Hey guys I got an '02 400ex from my brothers friend last year. Too be honest it sat in my brothers garage over the winter and it didnt work after that. My brothers other friend fixed it, said that a float was stuck (something in the carb? idk)... but anyway Im starting it up again I needed a new battery so when i hooked that up it was quick start..

however, when it was idleing it sounded to me like it was ready to stall at any second even though my friend said it sounded okay. If i didnt give it gas to keep it alive it would eventually die. Plus I remember I reved it high and when it came back down it would stall. So me and my friend simply turned the idle screw to raise the idle and that seemed to fix it, but in the manual it says not to fix a quad with the idle cause other things may be wrong... Is it okay that I did this? maybe the quad wasn't running smoothly because its been a long time since its been ran, no?

Thanks for anyones help! So excited to learn how to ride!! [img]i/expressions/face-icon-small-happy.gif[/img]

 

Real common problem! When it sits, the fuel dries up and cruds up the slow (idle/pilot) jet. This means you aren't getting enough fuel at idle, and will also be lean overall.

The carb needs to be cleaned, paying particular attention to the slow jet! After you reinstall it, properly adjust the fuel screw.

 

First, cleaning the carb is the best thing to do at this point. That may or may not solve your problem, but is a necessary step in the trouble shooting process. Second, make sure all the other routine maintenance is up to date on it. Start over with a fresh oil change, check the valve tolerances, service the air filter, fresh spark plug. As long as it runs OK on the current gas in the tank, I would ride that out of it once you get the other stuff squared away. Then start off with fresh gas and go back to the idle adjustment. The quad should be completely warmed up and off choke when and if you do adjust the idle again. While you are at it, wouldn't hurt to check all the bearings and pivot points over and service those too if needed. It is a little bit of work, but will give you piece of mind that the quad is ready to roll.

 

I was planning on riding with the quad this week now that it runs okay with the raised idle, is that okay?

Also, is cleaning the carb hard? I dont wanna take stuff apart and not know how to put it back together, yet, I DO wanna learn. thanks for your help guys..

oh yea one more thing, from me riding with my friend will it clean stuff out and make it run better in general? Thanks! [img]i/expressions/face-icon-small-happy.gif[/img]

 

Buy a can of sea foam engine cleaner and add it to the gas according to the directions before your next ride. That may be enough to clean it out.

 

The correct way to adjust the idle would be to use a syrometer which small engine stores would have and check to see the rpm of the engine that way and adjust it to specs. I would do the recommended above and drain the old fuel since it has been sitting for a while or so it seems. Do the regular maintanance like mentioned above along with cleaning the carb making sure you can see light through the jets and you should be fine.

 

MrFickle
While you are in the maintenance mood, wouldn't hurt to check the differential fluids (front and back)
If your friends friends friend had the machine in some deep water they could be contaminated, or
if they were like mine they might only have half the spec'd capacity from the factory!!!
I'm like you, I bought used and was very concerned about every little noise it made. I asked a lot of
questions to the good folks on this forum about what I could to make sure my bike would last a long time
and the most popular tip was to get a shop manual...which I did. Anyway good luck with your machine and
I'm sure it will last a long time.
Seemer

 

<div class="FTQUOTE"><begin quote>Originally posted by: Seemer

MrFickle

While you are in the maintenance mood, wouldn't hurt to check the differential fluids (front and back)

If your friends friends friend had the machine in some deep water they could be contaminated, or

if they were like mine they might only have half the spec'd capacity from the factory!!!

I'm like you, I bought used and was very concerned about every little noise it made. I asked a lot of

questions to the good folks on this forum about what I could to make sure my bike would last a long time

and the most popular tip was to get a shop manual...which I did. Anyway good luck with your machine and

I'm sure it will last a long time.

Seemer</end quote></div>

400EX's dont have differentials, but it was nice of you to look out for him. He should however take a look at the axle play, if the bearings are going out it will ruin a long ride quick.

 

Not to sounds like an a hole, but you won't have to worry about the diff fluid since there isn't a diff on the 400ex.

 

Sorry, wrong model
Don't tell anyone!!
Seemer