My 7 yr old L3400HST will not start after not using it for a week. I turn the ignition and it does nothing. I do this 3 or 4 times and there is not a sound. I jump up and down on the seat and move the HST rocker pedal back and forth and still nothing. I do this 10 more times and then it tries to start but the starter makes a grinding noise. Finally it starts and I will not have another problem starting it for the rest of the day. Then next week I will have the same problem . I had the starter rebuilt last year and it did fine for about a year. Time for a new starter? Take it to a mechanic? 