Can’t find your part?   Contact us:
+1-309-603-4777
Sears Parts Direct
Tips to find your model number
Orders

  • Keep track of the models you own in your profile

    Sign in or Register to view or add models

Schedule a repair
MTD
Lawn & Garden Engine

Model # 8Q78HU Official MTD engine

Here are the diagrams and repair parts for Official MTD 8Q78HU engine, as well as links to manuals and error code tables, if available.

There are a couple of ways to find the part or diagram you need:

  • Click a diagram to see the parts shown on that diagram.
  • In the search box below, enter all or part of the part number or the part’s name.

Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

We encourage you to save the model to your profile, so it’s easy to access parts and manuals for your appliance whenever you log in.

For DIY troubleshooting advice and repair guides, visit our repair help section.

Owner’s manual

Model diagram and schematic

SEARCH WITHIN THIS MODEL

?

This is the number corresponding to the part on the diagram / schematic

Search
ALL PARTS
Showing 10 of 180 parts  |
Lawn & Garden Equipment Engine Spark Plug 951-10292
#8

Cylinder head diagram

Lawn & garden equipment engine spark plug

Part #951-10292

Replaced by #951-10292A

?
Manufacturer substitution
This part replaces 951-10292. Substitute parts can look different from the original.
BEST SELLER
This item is not returnable
$5.70 | 
15% OFF Phone Price : $6.70
In Stock
Lawn & Garden Equipment Engine Carburetor Float Bowl Gasket 951-11349
#15

Carburetor diagram

Lawn & garden equipment engine carburetor float bowl gasket

Part #951-11349

Replaced by #951-11349A

?
Manufacturer substitution
This part replaces 951-11349. Substitute parts can look different from the original.
This item is not returnable
$5.64 | 
15% OFF Phone Price : $6.64
In Stock
Lawn Tractor Engine Oil Drain Plug (replaces 710-05311) 951-11644
#27

Crankcase diagram

Lawn tractor engine oil drain plug (replaces 710-05311)

Part #951-11644

This item is not returnable
$15.69 | 
11% OFF Phone Price : $17.69
In Stock
Lawn & Garden Equipment Engine Rocker Arm 951-11966
#13B

Cylinder head diagram

Lawn & garden equipment engine rocker arm

Part #951-11966

This item is not returnable
$12.82 | 
13% OFF Phone Price : $14.82
In Stock
Mtd Lawn & Garden Equipment Engine Air Filter (replaces 737-05145) 937-05145
#3

Engine shroud diagram

Mtd lawn & garden equipment engine air filter (replaces 737-05145)

Part #937-05145

$36.19 | 
14% OFF Phone Price : $42.19
In Stock
Mtd Choke Lever 951-15875
#16

Carburetor accessories diagram

Mtd choke lever

Part #951-15875

$9.83
In Stock
Mtd Lawn & Garden Equipment Engine Voltage Regulator 951-15920
#1

Ignition & electrical diagram

Mtd lawn & garden equipment engine voltage regulator

Part #951-15920

$149.80 | 
7% OFF Phone Price : $161.80
In Stock
Mtd Lawn & Garden Equipment Engine Electric Starter 925-07499
#3

Starter diagram

Mtd lawn & garden equipment engine electric starter

Part #925-07499

$358.19 | 
$12.00 OFF Phone Price : $370.19
In Stock
Lawn & Garden Equipment Engine Fuel Line Clamp 951-11700
#19

Carburetor accessories diagram

Lawn & garden equipment engine fuel line clamp

Part #951-11700

Replaced by #951-11700A

?
Manufacturer substitution
This part replaces 951-11700. Substitute parts can look different from the original.
This item is not returnable
$7.14
In Stock
Lawn & Garden Equipment Engine Intake Valve Seal 951-11964
#14

Cylinder head diagram

Lawn & garden equipment engine intake valve seal

Part #951-11964

Replaced by #951-11964A

?
Manufacturer substitution
This part replaces 951-11964. Substitute parts can look different from the original.
$19.71
In Stock

Repair guides for side-by-side refrigerators

How to replace a foamed-in-place door gasket in a side-by-side refrigerator

How to replace a foamed-in-place door gasket in a side-by-side refrigerator

The door gasket seals the gap around the door to keep the cold air in and the warm air out. Replace a worn or damaged do…

Read more
Repair difficulty
Time required
 30 minutes or less
How to replace a refrigerator water valve

How to replace a refrigerator water valve

Replace the water valve that feeds water to the ice maker and water dispenser if it no longer controls the flow of water…

Read more
Repair difficulty
Time required
 15 minutes or less
How to replace a defrost sensor in a side-by-side refrigerator

How to replace a defrost sensor in a side-by-side refrigerator

If frost is building up in the freezer of your side-by-side refrigerator, the defrost sensor could be at fault. You can …

Read more
Repair difficulty
Time required
 45 minutes or less

Effective articles & videos to help repair your lawn & garden engines

View all
Top questions about Sears and Sears PartsDirect

Top questions about Sears and Sears PartsDirect

Get answers to frequently asked questions about Sears and Sears PartsDirect.…

Read more
What are the main components of a lawn mower?

What are the main components of a lawn mower?

Learn about the main parts of a lawn mower and when to replace parts.…

Read more

Parts & More