Testing Oil Pump Pressure; Oil Pressure Relief Valve - Arctic Cat 650 Twin2004 Service Manual

REMOVING/DISASSEMBLING
1. Remove the oil pump from the engine (see
Left-Side Components in Section 3).
2. Remove the circlip (A) on the driveshaft; then
remove the inner rotor (B), outer rotor (C), oil
pump driveshaft (D), and the oil pump housing
(E).
CLEANING AND INSPECTING

NOTE: Whenever a part is worn excessively,
cracked, or damaged in any way, replacement is
necessary.
1. Clean all oil-pump components.
2. Inspect the rotors for scoring and gouges.
3. Inspect the driveshaft and driven sprocket for
damage.
4. Inspect the pump housing for cracks or damage.
ASSEMBLING/INSTALLING
1. Place the shaft into the pump housing; then install
the inner and outer rotors and secure with a circlip.
2. Install the oil pump into the engine (see Left-Side
Components in Section 3).
Testing Oil Pump
Pressure

NOTE: The engine must be warmed up to operat-
ing temperature for this test.
1. Connect the Arctic Cat Engine Tachometer (p/n
0644-275) to the engine.
2. Remove the oil pressure sender switch; then
connect the Oil Pressure Gauge (p/n 0444-039) to
the open port using a suitable adapter.

NOTE: Some oil seepage may occur when
installing the oil pressure gauge. Wipe up oil resi-
due with a cloth.
3. Start the engine and run at 4500 RPM.
4. The oil pressure gauge must read as 4.9 kg-cm
(69.7 psi).

NOTE: If the oil pressure is considerably lower
than specified, check the pressure relief valve, for
a damaged oil seal, for a defective oil pump, and/or
for crankshaft bearing insert wear.

NOTE: If the oil pressure is higher than speci-
fied, check for too heavy engine oil weight (see
Section 2), clogged oil passage, clogged oil filter,
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or improper installation of the oil filter.

Oil Pressure Relief Valve


NOTE: To remove the oil pressure relief valve,
the center crankcase must be separated (see Sec-
tion 3).
1. Remove the oil pressure relief valve (A); then
check the valve for debris or metal filings.
2. Using a wooden dowel (or other non-metallic
instrument), apply pressure to the relief valve
plunger (A) and ensure that it moves freely and
returns to the closed position by the force of spring
(B).
2
4
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