ALL YOU 400EX RIDERS, DO YOU HAVE A PROBLEM WITH
IT GOING UP ON 2 WHEELS WHEN CORNERING FAST AND
HARD. NEED HELP ON FIXING PROBLEM.

 

lean more on turns or get rid of the factory tires and go with a more flatter profile razors, holeshots, turf tammers, fast trekers etc.. my has a bone stock 91 250x and the tires on this bike tend to roll up on the sides on ther other hand i have an 87 250x with fast trekers and do not have a problem with thebike trying to go up on the side

 

Try airing up your rear tires to around 5psi. I used to ride my 300EX on pavement and I had them (the stock Ohtsu tires) pumped up to make it easier to turn. Then one day I went out onto a dirt trail and the thing was sliding all over the place. The higher pressure makes the tire taller and rounder resulting in less tire contact with the ground. Try this before you spend serious money on tires until you really need them.

 

On that note, I run about 9psi in my stock 400EX rears for 2 reasons:

1: The sidewalls are weak, that pressure allows me to crank it around the corners without as much sidewall roll (we have lots of rocks around here and it chews up the wheels too if you get too much sidewall roll, I know first hand).

2: The sidewalls are weak when landing big air, the wheels bottom out and get "Flintstoned"

Most aftermarket tires I have dealt with allow me to run about 4psi. I really like the stock 400EX rear tires with about 9 for the track a little less for general trail riding for a smoother ride.

 

I made a set of brackets that moved my shocks up higher which lowers the front end about a 1 3/4" (lower center of gravity = better handling around corners and less tipping) They still have the same amount of travel and it doesnt ride rougher. I do alot of hill climbing and it makes a difference on hills to, but of course if you do alot of jumping it tends to bottom out alot easier. I can change it back to factory height in about 5 mins, it all depends on what kind of riding I do.

 

Check out the rear shock preload. I had the same
trouble until I noticed that I did'nt have enough
preload. Without enough preload the total weight
will be shifted towards the rear of the ATV. You
can adjust it by turning the 2 spanner nuts at the
top of the shock down (which gives more preload).
The more you turn the spanner nuts, the more
rigid the suspension will be also. The front
end stays down better under hard acceleration and hills also.