Ive FIXED a number of pull starts,,,, on my Volcanoes and my buddies Avalanche.....
Its been my experience that once they start acting up, they dont STAY fixed for very long....I finally got sick of dealling with them...

You could buy a Roto start style back plate (Rotostart,Tigerdrive,etc) for about the same $$ or less than you would pay for a Pullstart.
If you have a good cordless Drill all you would need is the backplate assembly.

If you dont have a fast Cordless drill, you can get the Whole Shebang For less than $50.... Below are a couple of links. The first one is what my Buddy bought for his Avalanche(SH.28 Motor). The second link is what I use for my Volcanos (VX.18 Motors).It says for the Savage but it also fits my VX.18 motor.......Both Devices work well...
http://www.hobbypeople.net/gallery/145890.asp
http://www.hobbypeople.net/gallery/294010.asp

You will also need a Battery and charger if you dont have one. Here is a link for the batteries we use.....
http://www.hobbypeople.net/gallery/233060.asp

It might seem like a lot of $$, especially if you dont have a Battery n Charger already, but You WILL NOT regret the investment!