Checking Cooling System - Briggs & Stratton 272147 Repair Manual

TM
Vanguard Twin-Cylinder OHV Liquid-Cooled Engine
Section 2 - Troubleshooting
11. Disconnect outlet hose from tester before
removing from spark plug hole.
12. Repeat test for other cylinder.
The variation between the two cylinders should be less
than 20%. If the difference is greater than 20%, check
the cylinder with the lower reading.
Possible Causes for Poor Compression:
1. Loose cylinder head bolts
2. Blown head gasket
3. Burned valves, valve seats and/or loose valve
seats
4. Insufficient tappet clearance
5. Warped cylinder head
6. Warped valve stems
7. Worn bore and/or rings
8. Broken connecting rods

CHECKING COOLING SYSTEM

Pressure Testing Cooling System
1. Remove radiator cap and make sure coolant is at
correct level, Fig. 25.
a. Coolant level must be no more than 1 in. (.25
mm) below bottom of filler neck.
Fig. 25
2. Install cooling system pressure tester on radiator
and pressurize system to
: System must maintain pressure during
NOTE
test.
3. Check the following for any signs of leaking.
a. Hoses and connections (also check hoses for
excessive bulging)
b. Radiator
c. Water pump
d. Telltale hole in crankcase cover
e. Intake manifold and by-pass hose
f. Cylinder block and cylinder head
NOTE
: If coolant is evident at the telltale hole
in the crankcase cover, Fig. 26, this is an
indication that the water pump seal in the
crankcase cover is leaking, which may cause
coolant to enter the crankcase and contaminate
the oil. Severe engine damage could occur.
.
15 psi (1.03 Bar)
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