I am getting ready to give my new (used) boat a much needed tune-up. I'm reading throught eh Clymer manual and it says I need to get a shunt adapter to disable the electronic timing advance. Do I need to get this? Where do I find one? Can I just use something else in it's place. I'm not quites sure what a shunt adapter is, perhaps a jumper wire can work? Thanks.<br /><br />Mike