My son-in-law has a Simplicity Prestige tractor model 2691129. He recently had the oil sump gasket changed on the Briggs 30 hp professional engine. Everything was fine until yesterday. When he engaged the pto the tractor shut down. It was not due to excess load, but rather like the ignition was turned off. It will start right back up. The weak battery light also came on. He changed the battery but it did not solve the problem. The shop that changed the gasket (not sure if related or not) says he can look at it but might be a while. Any suggestions of where we can check in the meantime? The grass is growing. Thanks.