Mtd 731-05509 Line Trimmer Primer Bulb Genuine Original Equipment Manufacturer (OEM) Part This part is compatible with models including; 41CDZ45C799,41ADZ45C799,41DDZ45C799,41ADZ46C799,41BDZ46C799,316731702,316731703,316731704,316731973,316731930,316731700,316731931,41DDZ46C799,316731701,41ADZ47C799,41BDZ47C799,316731970,316731971,316731972 Primer bulb 731-05509 circulates fuel to the carburetor to provide quicker starting Genuine Original Equipment Manufacturer (OEM) part. Compatible Brands: Mtd This primer bulb (part number 731-05509) is for line trimmers Wear work gloves to protect your hands and work in a well-ventilated area during this repair