I think his switch should be a little yellow button mounted to the left of the steering wheel. He has replaced the switch with a new one, but it could be a bad one too. I have a similar LA175. Here's why I think it could be the switch that gets depressed when you back up... With the engine running, you can only get off the mower if the PTO is disengaged and the parking brake is set. The PTO can only be engaged when the seat switch is depressed, i.e. you are sitting on it. If you get off the seat while the PTO is engaged, or the seat switch is bad, the engine will die immediately. Also, the engine won't even crank unless you are in the seat and the clutch is disengaged. He said he was able to tape the Reverse Implement Option, or RIO as it is labeled on the mower, down and the mower ran normally. As far as I know, the only other switch that this RIO switch interacts with is the one on the reverse pedal for the hydrostat. I'm thinking it is stuck or bad, and is signalling that the machine is constantly in reverse.
But then again, I could be wrong.....wouldn't be the first. :ashamed: