Suspension Tuning for 2003 YZ 125

2003 YZ 125 Suspension setup

I just bought a new 2003 YZ 125. The bike was setup at the dealer and I want to know what changes should I make so that the bike rides better. I am 180-183 lbs without motocross gear so I assume it would be 190 Lbs.
I need to know if I should change the fork /and/or shock springs, the rate, the setting of compression and rebound damping of the forks and shocks as well as the race sag and all that.

Any advice is highly appreciate. As of now the bike in stock setting has some steering head shake and a nasty rebound kick in the back.

thanks

dbhagat

I weigh 185# and I have a month old 2003 YZ 125. I exprience headshake and rear end kick while riding. Any ideas where I can I find specific setting numbers according to rider weight for a stock bike.

I talked with Tech Care in Michigan and they suggested changing front and rear springs and revalving ( $ 700). I am looking for a less expensive and simpler alternative (tuning the suspension)

Thanks

dbhagat