Mercury YF7Z-6250-AA Camshaft

You can Select Your Vehicle to check if YF7Z-6250-AA fits your vehicle.

Begin by removing the valve cover(s) to access the camshafts and then remove timing chains, camshaft sprockets, and spacers. Measure the thrust clearance of the camshaft(s) with a dial indicator. If this is beyond the required value, instructions suggest changing the cylinder head or even the camshaft. Ensure correct reassembly of gathered-together cap clusters of bearing surfaces, Pay attention to specific bolts. Very carefully, lift off camshafts from the cylinder head taking care not to mix up any components. Do the same for another one. Visually check all lobes and bearing journals for signs of wear during an inspection. Use a micrometer to measure the diameter of the camshaft journal and lobe lift. Utilizing plastigage, oil clearance was checked for each camshaft journal. Inspect and clean the oil feed tube as well as a reservoir in the timing chain tensioner. The surfaces of both lobes and bearing journals should be liberally coated in moly-base grease or camshaft installation lube.

To check cam lobe wear, remove valve covers and position number one piston at TDC on compression stroke. Mount dial indicator on engine, align with first rocker arm, zero indicator, and slowly turn crankshaft to determine max cam lobe lift. Record figures for each valve by repeating process across cylinders. Compare results to specifications, and if lift is less than specified, replace camshaft. For removal, remove pushrods, valve lifters, timing chain, camshaft sprocket, and radiator. Check camshaft endplay, replace thrust plate if necessary, and remove camshaft using long bolt. Inspect camshaft for wear, pitting, and seizure. Measure bearing journals for wear or out-of-round conditions, and check camshaft lobes for discoloration, score marks, or chipping. If lobes are in good condition and measurements are within spec, camshaft can be reused. If bearing replacement is required, use special tools and follow instructions for removal and installation. Lubricate camshaft and bearing journals with engine assembly grease, then carefully slide camshaft into engine. Apply moly-base grease or assembly lube to both sides of thrust plate and install on block. Tighten bolts, and follow appropriate sections to reinstall lifters, pushrods, rocker arms, timing chain/sprocket, timing chain cover, and valve covers. Complete remaining installation steps in reverse order, change oil, and install new oil filter before starting engine.