BRP BOMBARDIER DS250 2006 Shop Manual page 39

Section 02 TROUBLESHOOTING
Subsection 01 (TROUBLESHOOTING CHART)
ENGINE SUDDENLY TURNS OFF.
Symptom:
3. Perform engine leak test. Check for possible piston seizure.
-
Damaged head gasket and/or seal and/or leaking inlet/exhaust valve(s). Replace and/or repair
defective parts.
4. Piston seizure.
-
Spark plug heat range is too low. Install spark plug with appropriate heat range (refer to TECH-
NICAL SPECIFICATIONS).
-
Compression ratio is too high. Install genuine parts.
-
Poor oil quality. Use a high quality oil.
-
Leaks at air intake manifold (engine gets too lean). Retighten screws or replace air intake man-
ifold.
5. Melted and/or perforated piston dome; melted section at ring end gap.
-
Spark plug heat range is too low. Install recommended spark plug (refer to TECHNICAL SPECI-
FICATIONS).
-
Coolant less than recommended level (engine gets too hot). Repair cooling circuit and/or refill
with recommended liquid.
6. Cracked or broken piston.
-
Cracked or broken piston due to excessive piston/cylinder clearance or engine over revving. Re-
place piston. Check piston/cylinder clearance (refer to PISTON AND CYLINDER).
7. Check piston rings and cylinder surface for grooves.
-
Poor oil quality. Use a high quality oil.
-
Contamination (like sand) through engine intake. Replace defective part(s) and use new air filter.
8. Check connecting rod, crankshaft, rocker arm rollers movement.
-
Connecting rod failure due to leak of oil. Repair and replace defective parts and use a high quality
oil.
-
Crankshaft failure due to leak of oil. Repair and replace defective parts and use a high quality oil.
-
Oil contamination due to clogged oil filter. Replace oil filter and oil at the same time, replace
defective part(s) (refer to LUBRICATION SYSTEM).
9. Check valve springs exhaust/inlet.
-
Broken valve spring damages the cylinder head, valve(s), rocker arm(s) and/or piston. Replace
defective part(s) and do the valve adjustment.
ENGINE DOES NOT OFFER MAXIMUM POWER AND/OR DOES NOT REACH
Symptom:
MAXIMUM OPERATING RPM.
1. Check items 1 and 2 of engine suddenly turns off.
2. Check air intake system.
-
Air filter is clogged due to contamination. Replace air filter.
3. Check spark arrester.
-
Spark arrester is clogged. Clean or replace spark arrester.
4. Check spark plug condition and/or gap.
-
Fouled spark plug or wrong spark plug gap. Readjust gap and clean spark plug or replace.
5. Check spark plug type.
-
Improper spark plug heat range. Install recommended spark plug (refer to TECHNICAL SPECI-
FICATIONS).
6. Perform engine leak test. Check for possible piston seizure.
-
Damaged head gasket and/or seal and/or leaking inlet/exhaust valve(s). Replace and/or repair
defective parts.
20
(cont'd)
vmr2006-065