Replacement Part List

ManualsBrandsDuromax ManualsEngines & Engine Parts18-HP 440cc 1 in. Shaft 4-Stroke Overhead Valve Portable Electric Start Engine

ISSUE

PROBLEM

SOLUTION

Throttle speed

increase responds

slowly, speed

drops, or engine

stalls

Low Compression

Piston, cylinder, or piston

rings are worn.

Replace worn parts.

Air leaking from below

the cylinder head.

Check cylinder head for

warping, replace gasket, and

torque to listed specifications.

Valve clearance is

incorrect.

Adjust the valve clearance.

Loose or misaligned

valve(s)

Repair and/or adjust valve seat

and/or spring.

III. Running Rough - Troubleshooting

ISSUE

PROBLEM

SOLUTION

Engine is pinging

Piston, cylinder, or piston rings are

worn.

Replace worn parts.

Piston pin and/or piston pin channel

are worn.

Replace piston and/or piston

pin

Connecting rod is worn.

Replace connecting rod.

Crankshaft bearing is worn.

Replace crankshaft bearing.

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