Mtd Ride On Mower Spares Or Repair

Mtd ride on mower. Has been used successfully used for many years but recently developed a fault, I have replaced oil, fuel filter, air filter , ignition solenoid and spark plug. But it still has problems keeping running . So I have had enough so that why I m selling for spares or repair . perhaps someone with more knowledge and patience may get her running again .comes with grass collector