2012 YZ 450F Handling

What exactly are you trying to improve?

Describe what the bike is doing that you want to fix.

Have you set your sag?

A cheap way to get more weight on the front wheel is to rotate you handlebars toward you a bit.

Raising the forks a few mm in the triple clamps will give you more of a front end bias.

Also you can change the bias by running less sag. For instance 95mm will put more weight on the front end. Calculate your sag wrong one time and you'll know this to be true like I did!

These are all free methods! You could also by lower bars, or offset triple clamps but I don't have much experience with those.

Buy a new rmz, haha, problem solved

I put my bars in the farthest forward mounting possible and run bars with less sweep so that it forces me to be more forward on the bike....more weight forward means more weight on the front tire. You could try moving your bars forward, Yamaha mounts them in the rear ward hole with the bar mount routed forward to make the bikes kind of neutral. If you move the mounts to the forward hole and spin them so that they face farther forward this should help. Sounds kind of confusing but once you look at the bar mounts you'll realize that if you spin them, they are made so that they either pull the bars rearward or more forward .

All the suggestions above will work...plus another little tuning trick for putting more weight on the front is to stretch your rear wheel as far back in the swingarm as you can...
you might need to buy a chain with two more links..or drop a couple teeth off the rear sprocket..
Moving the rear wheel back changes the weight bias more forward..
It's definitely noticeable!

Check your service manual for the stock fork tube runout. On my YZ125 its 5mm. You'll want to measure and be accurate. You simply loosen the fork pinch bolts on the triple clamp and slide them up a few mm. Don't over tighten the tubes you can damage them. It doesn't take much, My YZ is like 14 lbs and 17lbs.

And yes changing your sag by 5 mm will make a difference, this is why setting your sag is so crucial. It has a direct connection to handling. Think about it, with more sag the rear will squat lower and there will be less weight on the front wheel, good for sand. With less sag it won't squat as much and there will be more weight on the front, good for hard pack. A suspension guy I know described the relation like a see saw at a playground.