So you've heard that the KTM 690 Enduro has a great suspension, but in reality your bike pogos through rough sections or wallows in the whoops? Most likely you're the problem, not the suspension.
But it's not your fault, bike manufacturers are forced to set up their suspensions from the factory for "the average person." I've heard that 175 lbs is the magic rider weight, but that's anyone's guess. Good news though, unlike most dual sports, the 690 Enduro's suspension can be adjusted to suit most any rider and load.
First off, you have to set both "Static Sag" and "Rider Sag," front and rear. Both measurements are made while the bike is upright, so make a friend or get the dealer to help you.
Static Sag is the distance in millimeters that the bike settles under it's own weight. Free sag is between 5% and 10% of the total travel. The 2012 690 Enduro, for example, has 250mm of total travel, so the sag should be between 15 and 25 mm's.
Rider Sag is the amount the bike settles with the rider in riding position (feet on the pegs). The general rule of thumb is that the sag should be 25% to 33% of the total available travel (62.5 to 82.5mm's). If you are unable to get the total sag number you seek without either too much or too little static sag, you may need to change springs (depending on how much compromise you're willing to accept).
Set all the adjustments to stock standard settings as per the manual. This is your starting point. The general goal is to have both the front and rear suspension compress and return at the same rate, so the bike is balanced front/rear. Some folks have observed that from the factory the 690's front suspension is set stiffer than the rear. YMMV.
With rebound adjustment, the bike should not "pogo" when you press down quickly on the rear suspension, or top out too fast. Same for the front. You might make a few small changes from stock based on pushing the suspension up and down, see how it returns.
From there, its best to make your adjustments while riding the bike. I think the easiest thing to mess up is compression damping, having too much of it. This will make the ride harsh, it will "ping pong" off the rocks, and be hard to hold direction. The rear will have a "choppy" ride. Reduce your compression damping to the least you need. As speeds increase, you may need a bit more. The 2012 manual states: 20 clicks=comfort, 15 clicks=standard, 10 clicks=sport, 10 clicks="full payload."
On rebound damping, you dont want the bike to "pack down" as though its not rebounding fast enough after hitting bumps. On the other hand, you dont want it rebounding too fast and "topping out" or banging you in the butt. The manual's recommended clicker settings for rebound damping are the same as for compression damping.
Generally, as you ride faster, over rougher terrain, you may need more rebound damping to keep up with higher speeds, and maybe a bit more compression damping as you hit jumps, or whoops at faster speed.
So to re-cap:
1) Set sag correctly, front and rear.
2) Set tire pressures correctly for dirt, say 20 front and 22 rear? Tire pressure recommendations deserve their own thread, so I won't belabor the point.
3) Set compression and rebound settings at stock positions, or the settings you arrived at in the garage, from pushing down on the shocks. Note down what settings you have as you go on to 4 below.
4) Ride the bike, and make one change at a time, so you can feel the difference. You can even experiment by going to extreme setting so you can feel the difference, like maxium compression damping. Then back it off to get the best ride quality.
5) Reduce compression damping first, to get a plush ride.
6) Adjust rebound damping to get bike settled correctly.
7) Note down your settings that you like. As speed increases, or terrain becomes more technical and rough, make further adjustments as you feel needed. If you get confused from too many changes, go back to your baseline settings you wrote down, and try again.
Thanks to DRXXR at RideDualSport.com (
http://ridedualsport.com/forum/index.php?PHPSESSID=ts4b8bfrs3he2ldi6te2suo6f3&action=forum) for the lion's share of this tutorial. Also, thanks to James Siddall at the KTM 690 Wiki (
http://ktm690.info/index.php/The_Basics_-_James_Siddall)
Also, check out your manual! Beginning at page 64 (2012), the entire process is described (with pictures!).