when you connect the battery straight to the starter motor itself you are bypassing the solonoid. let me guess how you are doing that- red cable to the starter black cable to mower ground, right? If you are bypassing the solonoid with the ignition switch in the "start" position you need to by a new solonoid ($15.00) or make sure the cables are all attached good and tight to the solonoid are free of corosion. If you do not know what the solonoid is just follow the the red cable from the battery to a little thing with 2 poles on it. that red cable will attach to that little 2 poled thing which is the solonoid. There will be another another cable that comes out of it and then goes on to the starter.
If it starts everytime you bypass it, or at least turns over then that eliminates the ignition switch as the problem. You may get away with just a good cleaning. Clean all cable connections with sandpaper or a wire brush till they shine. If you replace the solonoid be very careful to get all the wires hooked to it in the same fashion as teh original. this might be a problem because some solonoids are universal and there may be hookups to it that do not meet you application needs. Always keep that batery charged up too!
fix it dude
July 2007