MTD Series 410 thru 420 Trouble Shooting, Problem Cause Remedy, For repairs beyond, Dealer

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Trouble

Shooting

For repairs beyond

the minor adjustments

listed here, contact

an authorized service

dealer.

NOTE: Specifications are subject to change without notification or obligation.

Images my not reflect your exact model and are for reference purposes only.

Problem		Cause		Remedy
Engine fails to start	1.	Blade control disengaged.	1.	Engage blade control.
	2.	Spark plug wire disconnected.	2.	Connect wire to spark plug.
	3.	Fuel tank empty or stale fuel.	3.	Fill tank with clean, fresh gasoline.
	4.	Engine not choked.	4.	Choke engine as instructed in the
				“Operating Your Lawn Mower” section.
	5.	Faulty spark plug.	5.	Clean, adjust gap, or replace.
	6.	Blocked fuel line.	6.	Clean fuel line.
	7.	Engine flooded.	7.	Wait a few minutes to restart, but do
				not prime.
Engine runs erratic	1.	Spark plug wire loose.	1.	Connect and tighten spark plug wire.
	2.	Blocked fuel line or stale fuel.	2.	Clean fuel line; fill tank with clean,
				fresh gasoline.
	3.	Vent in gas cap plugged.	3.	Clear vent.
	4.	Water or dirt in fuel system.	4.	Drain fuel tank. Refill with fresh fuel.
	5.	Dirty air cleaner.	5.	Refer to engine manual.
	6.	Carburetor out of adjustment.	6.	Refer to engine manual.
Engine overheats	1.	Engine oil level low.	1.	Fill crankcase with proper oil.
	2.	Air flow restricted.	2.	Remove blower housing and clean.
	3.	Carburetor not adjusted properly.	3.	Refer to engine manual.
Occasional skips	1.	Spark plug gap too close.	1.	Adjust gap to .030-inch.
(hesitates) at high speed	2.	Carburetor idle mixture adjustment	2.	Refer to engine manual.
		improperly set.
Idles poorly	1.	Spark plug fouled, faulty or gap too wide.	1.	Reset gap to .030-inch or replace
				spark plug.
	2.	Carburetor improperly adjusted.	2.	Refer to engine manual.
	3.	Dirty air cleaner.	3.	Refer to engine manual.
Excessive Vibration	1.	Cutting blade loose or unbalanced.	1.	Tighten blade and adapter. Balance
				blade.
	2.	Bent cutting blade.	2.	See an authorized service dealer.
Mower will not mulch grass	1.	Wet grass.	1.	Do not mow when grass is wet; wait
				until later to cut.
	2.	Excessively high grass.	2.	Mow once at a high cutting height,
				then mow again at desired height or
				make a narrower cutting path.
	3.	Dull blade.	3.	Sharpen or replace blade.
Uneven cut	1.	Wheels not positioned correctly.	1.	Place all four wheels in same
				height position.
	2.	Dull blade.	2.	Sharpen or replace blade.

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