815162170 Mercury SCREW (170 MM)

Model 346D
Table 1
Slave Piston Lash Settings    
All horsepower rating except for 460 Hp    
1.70 mm (.067 inch)    
460 Hp rating    
2.286 mm (.090 inch)    
Illustration 1 g00559207
Slave Piston Lash Adjustment (Typical Example) (1) Screwdriver (2) Adjustment screw (3) Locknut (4) Feeler gauges
Put the No. 1 piston at the top center position on the compression stroke. Refer toTesting and Adjusting, "Finding Top Center Compression Position For No. 1 Piston" .
Loosen locknut (3). With screwdriver (1), turn the adjustment screw (2) in order to make correct adjustments for cylinders 1, 3, and 5.Note: Be sure to check the lash with two feeler gauges (4) at the same time. One feeler gauge should be under each side of the slave piston.
After each adjustment, tighten locknut (3) to 22 N m (16 lb ft). Check the slave piston lash again.
Remove the timing bolt. Turn the flywheel through 360 degrees in the direction of engine rotation. This will put the No. 6 piston at the top center position on the compression stroke. Install the timing bolt in the flywheel.
Make an adjustment to the slave piston lash for cylinders 2, 4, and 6.
Remove the timing bolt from the flywheel when all adjustments have been made.Model 349A
Slave Piston Lash Adjustment
Table 2
Slave Piston Lash Settings    
All horsepower ratings    
0.457 mm (.018 inch)    
Illustration 2 g00559247
Adjusting Slave Piston Lash (1) Adjustment Screw (2) Locknut (3) Feeler Gauge
Put the No. 1 piston at the top center position on the compression stroke. Refer toTesting and Adjusting, "Finding Top Center Compression Position For No. 1 Piston" .
Loosen locknut (2). Turn the adjustment screw (1) in order to make correct adjustments for cylinders 1, 3, and 5.
After each adjustment, tighten locknut (2) to 35 N m (25 lb ft). Check the slave piston lash again.
Remove the timing bolt. Turn the flywheel through 360 degrees in the direction of engine rotation. This will put the No. 6 piston at the top center position on the compression stroke. Install the timing bolt in the flywheel.
Make an adjustment to the slave piston lash for cylinders 2, 4, and 6.
Remove the timing bolt from the flywheel when all adjustments have been made.Trigger Valve Adjustment
Table 3
Trigger Valve Settings    
Cylinder     400 Hp     All Remaining Engine Ratings    
1    
3.30 mm (.130 inch)    
2.54 mm (.100 inch)    
2,3,4,5,6    
2.41 mm (.095 inch)    
2.54 mm (.100 inch)    
The tolerance for all settings is
0.08 mm (.003 inch).    
Illustration 3 g00559315
Adjusting The Trigger Valve (1) Cap (2) Spring
Remove the cap (1) and the spring (2) from the trigger valve on the cylinder that is being adjusted. Do not remove the trigger valve. The first trigger valve adjustment should be on the same cylinder as the last slave piston lash adjustment.
Illustration 4 g00559439
Install the dial indicator assembly into the trigger valve bore. Hand tighten the dial indicator assembly until metal to metal contact is made.
Illustration 5 g00559768
Location Of The Master Piston and The Exhaust Rocker Arm Adjustment Screw (3) Master Piston (4) Exhaust Rocker Arm Adjustment Screw
The dial indicator extension will contact the trigger valve. This will push the master piston downward slightly.Note: The master piston must not come in contact with exhaust rocker arm adjustment screw at the time.
Set the dial indicator to zero.
Rotate the engine crankshaft slowly in the direction of rotation. The exhaust rocker arm adjustment screw will contact the master piston and the dial indicator needle will begin to move. Continue rotating the crankshaft until the trigger valve reaches maximum travel. After the trigger valve reaches the maximum travel, the trigger valve reverses direction. Record the maximum travel of the dial indicator.If the travel is not in the correct range that is given in Table 3, the trigger must be adjusted by the following procedure.
Illustration 6 g00559809
Remove the dial indicator