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Follow the original angle of grind as a guide. Make 
sure that each cutting edge receives an equal 
amount of grinding to prevent an unbalanced blade.

Balancing the Blade

The blade can be tested by balancing it on a round 
shaft screwdriver. Remove metal from the heavy 
side until it balances evenly. It is recommended that 
the blade always be removed from the adapter 
when testing for balance. 

Installing the Blade

Before reinstalling the blade and the blade adapter 
to the unit, lubricate the engine crankshaft and the 
inner surface of the blade adapter with light oil.

Be sure to install the blade with the side of the 
blade marked “Bottom” (or with part number) facing 
the ground when the mower is in the operating 
position.

Slide the blade adapter onto the engine crankshaft.

Place the blade on the adapter. Be certain the 
blade is aligned and seated on the blade adapter 
flanges.

Place blade bell support on blade. Make sure the 
notches on the blade bell support are aligned with 
small holes in the blade.

Replace hex bolt and tighten hex bolt to torque: 450 
in. lbs. min., 600 in. lbs. max.

NOTE:  To ensure safe operation of your mower,
periodically check the blade bolt for correct torque.

Replacing Rear Flap 

To remove rear flap, cut off the flat end of the wire 
rod which secures it to the deck. 

Attach the new flap and new rod to deck, bending 
the ends of the new rod over to secure to deck.

Storing Your Lawn Mower

The following steps should be taken to prepare your 
lawn mower for storage.

Clean and lubricate mower thoroughly as described 
in the lubrication instructions.

Refer to engine manual for correct engine storage 
instructions.

Coat mower’s cutting blade with chassis grease to 
prevent rusting.

Store mower in a dry, clean area. Do not store next 
to corrosive materials, such as fertilizer.

SECTION 9:  TROUBLESHOOTING

WARNING: 

An unbalanced blade will cause 

excessive vibration when rotating at high 
speeds. It may cause damage to the mower, 
and could break causing personal injury.

Problem

Cause

Remedy

Engine fails to start

1.

Blade control handle disengaged.

2.

Spark plug wire disconnected.

3.

Fuel tank empty or stale fuel.

4.

Blocked fuel line.

5.

Faulty spark plug.

6.

Engine flooded

1.

Engage blade control handle.

2.

Connect wire to spark plug.

3.

Fill tank with clean, fresh gasoline.

4.

Clean fuel line.

5.

Clean, adjust gap, or replace.

6.

Wait a few minutes to restart, do not prime.

Engine runs erratic

1.

Spark plug wire loose.

2.

Blocked fuel line or stale fuel.

3.

Vent in gas plugged.

4.

Water or dirt in fuel system.

5.

Dirty air cleaner.

6.

Carburetor out of adjustment.

1.

Connect and tighten spark plug wire.

2.

Clean fuel line; fill tank with fresh gasoline

3.

Clear vent.

4.

Drain fuel tank. Refill with fresh fuel.

5.

Clean air cleaner.

6.

Adjust carburetor.

Engine overheats

1.

Engine oil level low.

2.

Air flow restricted.

3.

Carburetor not adjusted properly.

1.

Fill crankcase with proper oil.

2.

Remove blower housing and clean.

3.

Adjust carburetor.

Excessive vibration

1.

Cutting blade loose or unbalanced.

2.

Bent cutting blade.

1.

Tighten blade and adapter. Balance blade.

2.

Replace blade.

Mower will not mulch grass

1.

Wet grass.

2.

Excessively high grass.

3.

Dull blade.

1.

Do not mow when grass is wet; wait until 
later to cut.

2.

Mow once at a high cutting height, then mow 
again at desired height.

3.

Sharpen or replace blade. 

Uneven cut

1.

Wheels not positioned correctly.

2.

Dull blade.

1.

Place all four wheels in same position.

2.

Sharpen or replace blade.

Summary of Contents for 549

Page 1: ...plicable local or state laws if any If a spark arrester is used it should be maintained in effective working order by the operator In the State of California the above is required by law Section 4442...

Page 2: ...help from the experts Choose from the options below Visit yardman com for many useful suggestions Click on Customer Support button and you will get the four options reproduced here Click on the approp...

Page 3: ...rotating parts or under the cutting deck Contact with the blade can amputate hands and feet 9 A missing or damaged discharge cover can cause blade contact or thrown object injuries 10 Many injuries oc...

Page 4: ...ooting or balance 2 Do not mow slopes greater than 15 degrees as shown on the slope gauge 3 Do not mow on wet grass Unstable footing could cause slipping Children Tragic accidents can occur if the ope...

Page 5: ...to improper performance and compromise safety 4 Mower blades are sharp and can cut Wrap the blade or wear gloves and use extra caution when servicing them 5 Keep all nuts bolts and screws tight to be...

Page 6: ...N T I N G A 1 5 S L O P E WARNING Do not mow on inclines with a slope in excess of 15 degrees a rise of approximately 2 1 2 feet every 10 feet A riding mower could overturn and cause serious injury If...

Page 7: ...pull back on the upper handle to raise the handle into the operating position See Figure 2 Make certain the lower handle is seated securely into the handle bracket assemblies Figure 2 Make sure that...

Page 8: ...came pre assembled proceed to the next section If it came unassembled follow the steps below to assemble it first before attaching to the mower Insert frame into grass bag with the black plastic side...

Page 9: ...Let mulch plug rest against the deck Operate mower without the grass catcher Refer to page 11 SECTION 4 KNOW YOUR LAWN MOWER Figure 12 Read this operator s manual and safety rules before operating yo...

Page 10: ...ld weather around 55 F or below prime five times Do not prime to restart a warm engine after a short shutdown Standing behind the mower depress the blade control handle and hold it against the upper h...

Page 11: ...ps from the weld pins on the handle brackets and remove the wing nuts and carriage bolts from the upper hole on the handle mounting bracket Press out on the legs of the lower handle and remove lower h...

Page 12: ...point on each end of the rear discharge door using a light oil This will prevent rusting of the discharge door Engine Care Follow the accompanying engine manual for detailed list and instructions SEC...

Page 13: ...ne storage instructions Coat mower s cutting blade with chassis grease to prevent rusting Store mower in a dry clean area Do not store next to corrosive materials such as fertilizer SECTION 9 TROUBLES...

Page 14: ...ARTS LIST FOR MODEL 549 1 6 7 8 9 10 11 12 13 18 19 2 49 50 55 56 57 58 59 61 62 40 47 54 53 51 52 65 37 42 40 39 36 15 35 22 31 32 16 25 29 26 49 30 49 23 49 21 20 34 43 45 64 29 24 49 33 17 36 5 14...

Page 15: ...82 5004A Rear Baffle RH 31 782 5003 Rear Baffle LH 32 710 1017 Tap Screw 1 4 14 x 625 33 712 3005 Flange Lock Nut 3 8 16 34 710 0703 Hex Carriage Screw 1 4 20 35 687 02033 Handle Bracket RH 687 02031...

Page 16: ...tments and normal deterioration of the exterior finish due to use or exposure d Service completed by someone other than an authorized service dealer e MTD does not extend any warranty for products sol...

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