400ex needs rebuilt, what to do..

[Slow Black SS]

I got a 2002 400ex on a trade, and its smoking.. starting to get worse. (ive changed the oil and filter, so its definately rings or seals)

Since im going to be inside the motor anyways, what should i do? 416, 426, or 440? I only putt around, do donuts and ride wheelies, no racing, and no major jumps.. so i don't need anything radical. and ill be doing the work myself, so cost isn't really an issue.

Any advice is great, im not sure on what compression to run or things of that nature.. so any advice at all would be great.

[dabensmiller]

If your not going to be doing anything to crazy just stick with the stock bore, but jump to a 11:1 comp. piston, then maybe throw a pipe and an air filter on it. If you want a little extra power.

[Slow Black SS]

Originally posted by dabensmiller
If your not going to be doing anything to crazy just stick with the stock bore, but jump to a 11:1 comp. piston, then maybe throw a pipe and an air filter on it. If you want a little extra power.

forgot to add it does have a DRD pipe, k&n filter and a hotcam.. but it runs real rich, and is smoking... bad on startup and and after i let it idle for a while it slows down but will smoke when you hit it hard..



edit- i was told by the previous owner it had the hotcam stage 1 in it, i have yet to find out...

[dabensmiller]

In that case it probably just needs to be jetted down, i experianced a simaliar problem on my first EX.

[Slow Black SS]

Originally posted by dabensmiller
In that case it probably just needs to be jetted down, i experianced a simaliar problem on my first EX.

im a newbie, so do ya got a "how-to" on the jetting? haha

or at least how to check whats in it..

[dabensmiller]

I think there is a how-to thing on this site, if not use a search engine to find something.

[dabensmiller]

Look under articles you will find wat u need

[buster024]

here's a link for the "how to" jetting issue. It's fairly simple. Just trial and error. Just ask if you get stuck.
http://www.exriders.com/vbb/showthread.php?s=&threadid=221872

[Slow Black SS]

Thanks