December 07, 2022

How to replace a snowblower spark plug

The snowblower spark plug creates the spark that ignites the fuel to start engine. If deposits build up on the spark plug electrode or if the ceramic insulation cracks, the spark plug won't create the spark. Fortunately, replacing a spark plug is an easy and inexpensive fix. This step-by-step snowblower repair guide shows how to install and gap a new spark plug using the manufacturer-approved snowblower part.

If the spark plug fouls quickly after you replace it, then engine problems could be apparent.

You’ll typically see either carbon deposits or oil deposits fouling the spark plug. The type of spark plug fouling often points to engine problems that you can resolve to prevent frequently having to replace the spark plug in your snowblower.

Carbon spark plug deposits

Carbon spark plug deposits are typically caused by:

Rich fuel mixture from a faulty carburetor.
Ignition system timing problems.
Faulty ignition system.
Prolonged idling.
Using the wrong spark plug.

Resolve these types of issues to prevent excessive carbon deposits on the spark plug.

Oil spark plug deposits

Oil deposits on the spark plug can be caused by overfilling the engine with oil or worn piston rings.

Check these issues when you see oil deposits on the spark plug.

Find additional tips for checking the snowblower spark plug in our How to check and replace a snowblower spark plug article/video.

Use these easy DIY instructions to replace the spark plug in Craftsman, Husqvarna, MTD, Murray, Honda, Toro, Yard-Man and Ariens snowblowers.

Quick links

Video

Instructions

Tools required

Spark plug gap gauge

Socket that fits the spark plug

Ratchet

Small hammer (optional)

Repair difficulty

Time required

15 minutes or less

How to replace the spark plug in a snowblower engine

Instructions

01.
Remove the spark plug
Disconnect the spark plug wire. Use a deep socket and a ratchet to remove the spark plug from the cylinder.
PHOTO: Remove the spark plug.
02.
Gap the new spark plug
Check your owner’s manual for the correct gap setting. Insert the gap gauge between the electrodes on the spark plug. The gap gauge should fit snuggly between the electrodes; when you pull it out, you should feel only slight resistance. If the gap is too wide, lightly tap the electrode on a clean, hard surface or use a small hammer. If the gap is too small, use the bender on the gap gauge to widen it.
PHOTO: Gap the spark plug.
03.
Install the plug
Thread the spark plug into the cylinder. Hand-tighten the spark plug until it’s snug and then use the ratchet and deep socket to tighten the spark plug another ¼ to ½ turn. Don’t overtighten, because the steel base of the spark plug can strip the softer aluminum threads on the cylinder head.
Reconnect the spark plug wire.

Warning: Undertaking repairs to appliances can be hazardous. Use the proper tools and safety equipment noted in the guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs should only be performed by a qualified technician.