I just wanted to share a very easy way to back bleed your front brakes. Back bleeding is just one of many ways to remove trapped air. Trapped air contributes to the spongy feeling.
Place your handlebars so that the brake line rises as straight as possible to the reservoir. (Turn the bars to the left). You'll want to make sure the reservoir isn't over full. You need a place for the air to go. Leave the cap on so you don't spill brake fluid on the tank. I always place a large bath towel on the tank so as not to scratch.
Slip the bar clamp between the wheel spokes, resting the plastic jaws on the outside of the calipers. Snug the jaws so that they hold the clamp in place. The calipers slide axially on pins. This works because fluid is being forced from each caliper at the same time forcing the air back to the reservoir.
On the stock master cylinder you will apply and release the brake lever a couple times a second. You only want to move the valve in the master cylinder enough for the holes to allow air to get past and rise up into the reservoir. Somewhere between 1/4 and inch of lever throw depending on how much air is in there. If you had help, you could also crack the line at the master cylinder, letting the air escape as pressure was applied with the clamp.
So with your left hand work the lever as described above. With your right hand apply pressure with the clamp. That's all there is too it.
I you have the radial master cylinder
I described, there is a bleeder at the top which you can crack as you apply pressure to the clamp. Be sure to put a piece of tubing on the bleeder to catch the fluid.