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Troubleshooting – Dolmar MS-251.4 User Manual

Page 23

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TROUBLESHOOTING

Before making a request for repairs, check a trouble for yourself. If any abnormality is found, control your machine according to the
description of this manual. Never tamper or dismount any part contrary to the description. For repairs, contact Authorized Service Agent or
local dealership.

When the engine does not start after warm-up operation:
If there is no abnormality found for the check items, open the throttle by about 1/3 and start the engine.

State of abnormality

Probable cause (malfunction)

Remedy

Failure to operate primer pump

Push 7 to 10 times.

Low pulling speed of starter rope

Pull strongly.

Lack of fuel

Feed fuel.

Clogged fuel filter

Clean

Broken fuel tube

Straighten fuel tube

Deteriorated fuel

Deteriorated fuel makes starting more difficult.
Replace with new one. (Recommended
replacement: 1 month)

Excessive suction of fuel

Set throttle lever from medium speed to high
speed, and pull starter handle until engine
starts. Once engine starts, cutter blade
starts rotating. Pay full attention to cutter
blade.

If engine will not start still, remove spark plug,
make electrode dry, and reassemble them as
they originally are. Then, start as specified.

Detached plug cap

Attach securely

Contaminated spark plug

Clean

Abnormal clearance of spark plug

Adjust clearance

Other abnormality of spark plug

Replace

Abnormal carburetor

Make request for inspection and maintenance.

Starter rope cannot be pulled

Make request for inspection and maintenance

Engine does not start

Abnormal drive system

Make request for inspection and maintenance

Insufficient warm-up

Perform warm-up operation

Choke lever is set to “CLOSE” although engine
is warmed up

Set to “CLOSE”

Clogged fuel filter

Clean

Contaminated or clogged air cleaner

Clean

Abnormal carburetor

Make request for inspection and maintenance

Engine stops soon
Engine speed does not increase

Abnormal drive system

Make request for inspection and maintenance

Loosened cutter blade-tightening nut

Tighten securely

Twigs caught by cutter blade or
dispersion-preventing cover

Remove foreign matter

Cutter blade does not rotate

Abnormal drive system

Make request for inspection and maintenance.

Broken, bent or worn cutter blade

Replace cutter blade

Loosened cutter blade-tightening nut

Tighten securely

Shifted convex part of cutter blade and cutter
blade support fitting

Attach securely

Main unit vibrates abnormally.

Abnormal drive system

Make request for inspection and maintenance

High idling rotation

Adjust

Detached throttle wire

Attach securely

Cutter blade does not stop immediately.

Abnormal drive system

Make request for inspection and maintenance

Detached connector

Attach securely

Abnormal electric system

Make request for inspection and maintenance.

Engine does not stop.

Stop engine immediately

Stop engine immediately

Stop engine immediately

Run engine at idling, and set choke
lever to CLOSE.