181
CID (3.0L) 4 CYLINDER GM ENGINE
SERVICE MANUAL NUMBER 26
Valve Springs - Checking Tension
Using valve spring tester, as shown, check valve spring tension with dampers removed.
Refer to “Specifications.”
IMPORTANT: Springs should be replaced if not within 10 lbs. (44 N) of specified
tension.
b
a
72308
a - Valve Spring Tester (J-8056)
b - Torque Wrench
Valve Seats
Valve seat reconditioning is very important, since seating of valves must be perfect for
engine to deliver maximum power and performance.
Another important factor is valve head cooling. Good contact between each valve and its
seat in head is important to ensure that heat in valve head will be properly dispersed.
Several different types of equipment are available for reseating valve seats. Equipment
manufacturer’s recommendations should be followed carefully to attain proper results.
Regardless of type of equipment, however, it is essential that valve guide bores be free from
carbon or dirt to achieve proper centering of pilot in valve guide and ensure concentricity.
a
72338
a - Check Valve Seat Concentricity
Valves that are pitted must be refaced to the proper angle. Valve stems which show exces-
sive wear or valves that are warped excessively must be replaced. When a valve head that
is warped excessively is refaced, a knife edge will be ground on part or all of the valve head
due to the amount of metal that must be removed to completely reface. Knife edges lead
to breakage, burning or pre-ignition due to heat localizing on this knife edge. If the edge of
the valve head (margin) is less than 1/32 in. (0.8 mm) after grinding, replace the valve.
Index
Page 3A-30
90-861329--1 MARCH 1999
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 181 CID |
| Model Year | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(6 votes, average: 5 out of 5)
Marine readers have rated Mercury MerCruiser GM 4 Cylinder 181 cid 3.0L Marine Engines Service Manual Number 26 5.0 out of 5.0 based on 6 product reviews. Thanks for sharing this material. Helps a lot after suffering with bad mechanics. spend too much money and nothing very good
great manual, makes impossible jobs possible. without a manual you can not do the job, a must have.
Great resource. Excellent information provided.
Need help to install automate choke
Need help to instal automate choke