Ok, I just got a 400EX yesterday and am wondering if there are any must do mods to do to it. It already has a WB E-series exhaust, Uni-filter, AC nerfs, and shock covers. I know the guy I bought it off of and it has barely even been rode. Still has the nipples and red marks on the tires. So give me some tips for the new quad of mine. Thanks,

Nick

 

new tires for your type of ridding, and if your gonna be racing(mx,tt,ect.) get your chssis componets, widder axle a-arms, better shocks and then do your motor

 

Given the fact that the mold marks are still on the tires, it would indeed seem that it hasn't been ridden much, at least the tires haven't. I would then treat is as brand new, change the oil, and follow the same break-in procedure as if it came off the dealer's floor.

 

There aren't any "must do" mods except to increase the tire pressure on the rears to 5lbs to help with the sidewalls. They tend to roll and get sliced rather easily...almost every owner runs into this problem. No sence getting new rubber yet, the ohtsu's can't be beat for "hook up" capabilities.
Also, make sure the carb slide is rising all the way up during full throttle! There is free power there which honda seemed to overlook at the assembly line on all 2000's. The adjustment is simply at the thumb throttle but the boot must be taken off the carb to see the slide action. This is your must do mod if it hasn't been done already! Enjoy

 

The rear tires are a little on the wimpy side. Ridden it three times and got two flats. Although they do get better traction than any tire I've used before. That is the only mod I have done or plan to do. I don't like loud bikes and the performance is great just the way it is.

 

I actually think I've found an easier way to adjust the throttle cable... Just turn the adjustment on the thumb-throttle all the way in, then hold it at full throttle with light pressure, and back the adjustment out until it just begins to pull the throttle lever back. Then you know that the slide in the carb is all the way topped-out at full throttle, and from there you can adjust it a little tighter if need be to remove free-play a the beginning of the throttle.