Just bought a '99 400ex. Need advice.

[wheelman]

Earlier today I bought a pretty clean 99 400ex. Everything seems to be in pretty good shape for a quad its age, but it had a few issues I was curious about.

First of all, it is tough to start. I see that they can be tricky to start in the cold. It was only about 55 tonight and it acted a little bit like it had a weak battery. I eventually got it turned over using some choke and it died as soon as I shifted into first (with the clutch pulled in, mind you) One more try and I got it going and it seems to run great once I get moving. No smoke or anything coming from the engine.

Second, it is missing the tail light. Any place I can find a diagram of the rear assembly so that I can see if anything is missing besides the lens assembly itself? I can see the bulb socket dangling back there, but there is no bulb.

Also, just curious what if anything else I should look into to getting it running tip top? The owner just recently changed the oil and the air filter was clean as could be.

Any suggestions appreciated.

Thanks in advance!

[trailrider894]

Originally posted by wheelman

Second, it is missing the tail light. Any place I can find a diagram of the rear assembly so that I can see if anything is missing besides the lens assembly itself? I can see the bulb socket dangling back there, but there is no bulb.

Also, just curious what if anything else I should look into to getting it running tip top? The owner just recently changed the oil and the air filter was clean as could be.

Any suggestions appreciated.

Thanks in advance!

Welcome to the addiction........... :cool: and welcome to the forums. :macho

Okay, about the tail light. If you can see the hook up for the bulb, all you need is the tail light itself, the rubber pieces that attach the lense to the subframe and a bulb. Pick up a service manual for you EX, it will have everything you need to do anything to your EX including all the schematics for the electrical system.

Pull out the spark plug and check to see what color it is and let us know. You should get a new spark plug and make sure the gap is correct on the new plug then install it. It really sounds like your pilot jet is off, but i am not a carb junkie... Just know enough to get by.

[Rkangel7]

400ex's are cold blooded and can benefit from going up a size on the pilot jet. Also if the battery is old or getting weak it's a good idea to replace it. A strong, good condition battery will make starting nicer for the simple fact that you'll have a little more reserve cranking power for those cold days when ol' girl needs a little more persuasion to start.

[duroc825]

You could go to a site that sells OEM parts like motosport.com and look at entire schematics of the whole quad. I believe rmatv now does OEM parts in the same way now too.

[quad2xtreme]

grease the swingarm bolt...assuming you can get it out. The bolt is notorious for seizing to the two sleeves/collars that the bearings ride on.

If the bolt in seized, you will need to cut it out with a sawzall.

There are tons of posts on this topic throughout the forum.

[DragonGunner]

Originally posted by Rkangel7
400ex's are cold blooded and can benefit from going up a size on the pilot jet. Also if the battery is old or getting weak it's a good idea to replace it. A strong, good condition battery will make starting nicer for the simple fact that you'll have a little more reserve cranking power for those cold days when ol' girl needs a little more persuasion to start.

This^^^^ also you can put some gumout carb cleaner in the tank, I've had to take my carb off an tear down an clean, if it hasn't ran for a long time old gas can gum things up.