Mercury 1S7Z-6507-AA Valve - Inlet

You can Select Your Vehicle to check if 1S7Z-6507-AA fits your vehicle.

First, pull the battery cable away from the negative terminal; remove all of the spark plugs and the valve cover. Some of the challenges are Loosen the right front wheel lug nuts-lift the front of the vehicle-support the vehicle secured on jack stands-remove the right front wheel and the fender splash shield. On another engine, with a wrench or socket on the crankshaft pulley bolt, turn the crankshaft clockwise and check each lifter when its camshaft lobe is directly vertical, it's preferred that the distance is between cam base circle and top of the lifter. The correct clearances are obtained by the use of feeler gauges with a very slight drag being felt when sliding the gauge between the lifter and camshaft. A measurement check should be carried between the clearance of each of the camshaft lobe with the appropriate lifter and document all the readings. In the event that any of the anterior mentioned clearances prove to be out of standard, both the camshafts and lifters that are out of spec must be withdrawn. New lifters are available in various thicknesses, it is stamped with a thickness number; only the numbers after the decimal point are important. To decide the lifters' thickness for a new set, sum together the thickness of an original lifter and the measured clearance, and then subtract the midrange figure for the ideal clearance to arrive at the proper thickness of the lifter to order, choosing the closest available thickness. After the camshafts and timing chain have been fitted, it is essential to again inspect the valve clearances; after that, the work is done in reverse order. Last but not least of the oil change procedures is to start the engine and inspect it for oil loss.

In this type of engine there is no manufacturer set service schedule for checking on the valve clearance, although high mileage or even a noisy valve train may might call for it. Before testing the valve clearances on the hydraulic lifters, the valve cover has to be removed and set the Number 1 cylinder on top dead center of the intake stroke while the exhaust and intake cam lobes face upward. Insert a feeler gauge below the cam lobe of the Number 1 cylinder and measure the thickness of the clearance between the cam lobe and the tappet and record the thickness of the four valves of the cylinder. Then, rotate the crankshaft further to 180 degrees to check clearances of the cylinder Number 3, check the cylinders Number 4 and 2, also. If any is seen to be outside the required range, then it should be corrected and a record of which valves have to be adjusted should be taken on a chart. Examining valve clearances is relatively easy, but adjusting them is quite a problem and this should be done with a micrometer. Should there be changes necessary, other camshaft tappets of different thickness will require to be used and precise measurement has to be done in order to choose the right tappet. If the clearance is to be small, a thin tappet should be installed; while if the clearance is to be large, a thick tappet will do. Once you have established the needful tappets, get them at a local dealership. Place the engine at Top Dead Center, torque the valve cover and front engine cover, take off the timing chain and both camshaft gears and both camshafts. When having to remove and replace tappets, and there are many, it is advised that they should be done one at a time to avoid mixing them because their faces may be of different thickness. Apply oil on the new tappets that you are going to fit and having fitted them, reverse the process of removing the tappets and before tightening any bolt or nut, oil the cam lover and journals, check and recheck the valve clearances, tighten tappets in the correct sequence followed by torquing every bolt that you tightened, and check all electrical and hose connections for proper connectivity and tightness. To start with, you should take your time and reinstall the engine so as to result to a precise automobile so as to cover up for a leak should there be one.

For the 2.0L engine, start by unscrewing of the valve cover while positioning the number 1 cylinder on TDC on the compression stroke while the intake and exhaust cam lobes are facing upwards. The thickness of shims that fits tightly should be noted by measuring the clearance between the cam lobe base and the shim using feeler gauge for each valve. Turn the crankshaft again by 180 degrees clockwise to take the clearances for the cylinder No. 3, and also for the cylinder No. 4 and No. 2. If they are clearances are beyond the set range, some changes will be required. Because of the restricted installation space of the camshafts and cylinder head special tools are used for adjustments. To change a shim, you need to lower the piston from TDC by merely turning the crankshaft roughly 90 degrees clockwise in order to prevent the bending of the valve. Refer to the manufacturer service tool to proceed and lower the cam follower while taking off the shim and measuring its thickness. In the vicinity of small clearance, use a thinner shim; at large clearance, use a thicker shim. Once you have adjusted the clearances on the first cylinder, turn the crankshaft two full turns in order to set all installed shims, bring the crankshaft back to TDC and check all the clearances once again adjusting them if necessary. As for the 2.3L/2.5L engines, the procedure to check the valve clearances is quite the same as with the 2.0L, but due to the use of hydraulic tappets and cam followers with heads of various thickness to obtain the required clearance, the camshafts have to be removed to change followers.

5. If adjustment is needed, change the shim thickness by depressing the cam follower, removing the old shim, and fitting a new one. 6. Before changing a shim, lower the piston for the relevant cylinder from its TDC position by turning the crankshaft approximately 90° clockwise to avoid the risk of bending the valve. 7. Dealer technicians use service tool 303-563A, which is bolted onto the cylinder head above each camshaft using two of the camshaft bearing cap bolt locations. A spacer may be required to allow the tool to be bolted onto the head. 8. Take care not to scratch or damage the cam follower and its housing. Remove the shim with a small screwdriver or magnetic probe, then slowly release the pressure applied to the tool. Do not rotate the camshaft while a shim is removed. 9. Record the thickness of the shim, which is engraved on the side facing away from the camshaft. If the marking is missing or illegible, a micrometer will be needed to establish shim thickness.

1. Examine the head of each valve for pitting, burning, cracks, and general wear, and check the valve stem for scoring and wear ridges. 2. Rotate the valve and check for any obvious indication that it is bent. Look for pits and excessive wear on the tip of each valve stem. Replace any valve that shows signs of wear or damage. 3. If the valve appears satisfactory, measure the valve stem diameter at several points using a micrometer. Any significant difference in the readings indicates wear of the valve stem, and the valve(s) must be replaced if conditions are apparent. 4. If the valves are in satisfactory condition, they should be ground (lapped) into their respective seats to ensure a smooth gas-tight seal.

Replace the camshaft cover.

After the valve job has been performed by a professional, the head will be in like-new condition. When the head is returned, be sure to clean it again before installation on the engine to remove any metal particles and abrasive grit that may still be present from the valve service or head resurfacing operations. Use compressed air, if available, to blow out all the oil holes and passages.

If the valve clearance was too large, a thicker-faced tappet must be installed.

It is helpful to keep a record of the thickness of the shims fitted at each position.

After the valve job, the head will be in like-new condition. Before installation on the engine, it is important to clean the head again to remove any metal particles and abrasive grit that may still be present from the valve service or head resurfacing operations. Using compressed air, if available, is recommended to blow out all the oil holes and passages.