I have a TroyBilt 17.5 HP Pony Riding lawn mower with electronic starter that will not start. I've owned and used the mower approximately 2 years old without any problems at all until now.

Here's what's happened so far:

A month ago the engine wouldn't make a sound when I tried to start it. Not even a clicking noise. I worked a few gears and the clutch just to make sure everything was set right, and after a few minutes it started and was running strong. I figured it was just a one time hangup.

About 3 weeks ago, it again wouldn't make a sound. I figured it was a dead battery and tried to jump start it from a vehicle battery. No luck. Took the battery back and replaced it with a new one and it fired right up so I figured it was in fact a dead battery and I just got a fluke from the factory that didn't last very long.

Last week it did it again. Hit the ignition and not a sound. I tried following some of the checklist directions I've seen elsewhere, and ran a jump cable from the positive battery terminal of the mower battery to the starter with no success. Did the same with a good battery, and again no success. Finally hooked up the jump cables between the good battery and the bad battery, and it started hesitantly then fired up on the 3rd or 4th try.

Figuring I'd better mow my grass while I had the chance since it hadn't been mowed in a while, I mowed approximately 7/8 of an acre. During that time it ran without hesitation or smoking, and had no loss of power that I could tell, then I pulled it back into the garage.

It may have run for 1 1/2 to 2 hours at most. The grass was just regular lawn, and while a bit taller than I'd like it was nothing abusive for the mower to cut easily.

15 or 20 seconds after I shut it down, I decided to hit the ignition again to see what would happen and it fired right up without hesitation, so I figured it was working OK again.

A couple of hours later I was going to move it, only this time it was dead again without even a sound when I hit the ignition.

I figure the starter and ignition are good, otherwise it wouldn't have started.

If the generator had gone bad, could the battery have been low, with enough power for it to run off but not enough left to start it? Could a bad generator be the problem and running the battery down?

Or is it one of the safety switches? If so, is it normal for them to operate intermittently when they go bad?

I would think if it was a bad safety switch then it would not have allowed it to start at all, and I have always been under the impression a bad safety switch is bad safety switch, and not bad just some of the time. If bad, it won't start, if good, it will start.

Or could it be the solenoid or something else I haven't thought of?

Any help would be appreciated.

Whew, long posting, lets see what i can remember about your unit. Oh yeah, i would set the valves, this can act like a bad battery. Did you purchase a quality battery with at least 300 cca s?? The starters on the lawnmowers will perform better with 300 cold cranking amps. With you jumping from a good battery directly to the starter and not getting any results, that leads to either a worn starter, or the valves. Try what you can and when you respond , perhaps it will be less possibilities.