Kohler MAGNUM M18

SECTION 4
TROUBLESHOOTING
Cylinder Leakdown Test
A cylinder leakdown test can be a valuable altemative
to a compression test. By pressurizing the combus-
tion chamber from an extemal air source you can de-
termine if the vatves or rings are leaking, and how
badly:
The Kohler Part No. 47 800 02 is a relatively simple,
inexpensive leakdown tester for small engines. The
tester includes a quick disconnect for attaching the
adapter hose and a holding tool.
Leakdown Test Instructions
1. Run engine for 3-5 minutes to warrn it up.
2. Remove spark plug(s) and air filter from engine.
3. Rotate crankshaft until piston (of cylinder being
tested) is at top dead center of compression
stroke. You will need to hold the engine in this
position while testing. The holding tool supplied
with the tester can be used if the PTO end of the
crankshaft is accessible. Slide the holding tool
onto the crankshaft and adjust the set screw to fit
in the key slot. Instalt a 3/8" breaker bar into the
square hole of the holding tool, so it is perpendic-
ular to both the holding tool and crankshaft PTO.
if the flywheel end is more accessible, you can
use a breaker bar and socket on the flywheel nut/
screw to hold it in position. You may need an as-
sistant to hold the breaker bar during testing. If
the engine is mounted in a piece of equipment,
you may be able to hold it by clamping or wedg-
ing a driven component. Just be certain that the
engine cannot rotate off of T.D.C. in either
direction
4. Install the adapter into the spark plug hole, but do
not attach it to the tester at this time.
5. Connect an adequate air source to the tester.
m
Turn the regulator knob in the increase (clockwise)
direction until the gauge needle is in the yellow
“set” area at the low end of the gauge.
7. Connect tester quick-disconnect to the adapter.
Note the gauge reading and listen for escaping air
at the carburetor intake, exhaust outlet, and crank-
case breather.
8. Check your test results against the table below:
LEAKDOWN TEST RESULTS
Air escaping from crankcase breather . .
Air escaping from exhaust system . .
Air escaping from carburetor . .
Gauge reading in “low” (green) zone ..
Gauge reading in "moderate" (yellow) zone ...........
Gauge reading in "high" (red) 20пе ..................
Defective rings or wom cylinder walls.
Defective exhaust valve.
Defective intake valve.
. Piston rings and cylinder in good
condition.
erent dd Mese Engine is still usable, but there is some
wear present. Customer should start
planning for overhaul or replacement.
VERUS Vases Rings and/or cylinder have considerable
wear. Engine should be reconditioned
or replaced.
4.5