RX 75

Just bought a RX 75 for my parents to mower there yard. I put new primary and secondary belts on it. Now the mower runs buts dies as soon as I put it in gear. Is there a safety switch somewhere that is bad? The safety switch for the seat is disconnected. Any ideas?
Thanks
Matt

a wiring schematic of the switches would be a big help but I have not been able to tack one down. If anyone knows where I can print one out that would be great.
Thanks
Matt