Lawn Mower Spark Plug Gap Chart (14 Engines, Measured)
Set the gap to 0.020-0.030 in (0.5-0.76 mm). Measured gap and size specs for Briggs, Honda, Kohler, Kawasaki and Craftsman engines, plus socket sizes.
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Every repair and maintenance guide
Each one is tested on a real mower by Akshay Singh before it’s published, and dated when it changes. Pick a topic, or search for the part, symptom or brand you’re dealing with.
The library
- Guides published
- 142
- Topics
- 2
- Newest guide
- September 11, 2026
- Tested and written by
- Akshay Singh
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Showing 106–120 of 142 guides, newest first
Lawn Mower Spark Plug Tester: 5 Tested (1 Worth Buying)
Tested 5 lawn mower spark plug testers on 4 engines in spring 2026. See the $6 inline pick that wins, which to skip, and how to use one in 60 seconds.
Lawn Mower Spark Plug Socket Size (5/8 vs 13/16, 12 Plugs)
Check the plug, not the mower. Most lawn mower spark plugs take a 5/8-inch (16 mm) or 13/16-inch (21 mm) socket. Size chart by engine, plus 5 tested picks.
How to Clean a Lawn Mower Spark Plug (and When Not To)
Clean a fouled mower spark plug in 10 minutes: wire brush the carbon, solvent the rest, re-gap to .030 in. Plus when the plug is past saving.
Test a Lawn Mower Spark Plug (Skip the Ohm Test)
Test a lawn mower spark plug three ways in under 10 minutes: the ground-and-pull spark check, an inline tester, and the ohm test that misleads most owners.
Foam Air Filter Lawn Mower Guide (9 Filters Tested)
Compare foam vs paper before you buy: which engines need foam, whether you must oil it, cut-to-size sizing, and how long a foam filter really lasts.
Replace a Lawn Mower Air Filter in 4 Minutes (5-Mower Test)
Replace a lawn mower air filter in 4 minutes. Get the 7-step swap, the orientation photo trick, and the real replace interval for your engine.
Electric Lawn Mower Tune-Up: There Isn't One (Do This)
Skip the tune-up: electric mowers have no spark plug, air filter or oil. Here are the 4 jobs that matter, with intervals, costs and a gas-vs-electric table.
How to Clean a John Deere Lawn Mower Air Filter (2026 Test)
Tap the paper cartridge, wash the foam pre-cleaner, and check the oiling rule for your model year. Covers 100, D, E, L, S and X Series riders.
How to Change a John Deere Spark Plug (V-Twins Take Two)
Swap your John Deere spark plug in 15 minutes: a 5/8″ socket, a .030″ gap, and why V-twin riders have two plugs - plus how often to replace it.
John Deere Spark Plug: Find Your Part by Model (RC12YC)
Find the right John Deere spark plug by model: M78543 (RC12YC), the NGK/Champion cross-reference, the .030 gap, socket size, and why V-twins take two.
John Deere Air Filter Finder: MIU14395 or GY-Series (2026)
Match your John Deere riding mower air filter by model: MIU14395 fits most 100-series; GY-series covers L/LA V-twins. Read your tag, pick OEM or aftermarket.
How to Tune Up a John Deere Mower (5 Steps + LG Kit)
Tune up your John Deere in 5 steps — oil, air, fuel, plug(s), blade. Match the right LG kit to your model and skip the $100–$350 dealer bill.
Craftsman Lawn Mower Tune-Up Kit: Read Your 917 First
Match the right Craftsman tune-up kit to your 917 model and engine. See genuine vs aftermarket value, what's inside each kit, and where to buy.
How to Clean a Craftsman Air Filter (Without Wrecking It)
Clean a Craftsman mower air filter right: wash and re-oil foam, tap or replace paper, service dual-stage - and know when to swap it instead.
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Tell us what the mower is doing: the model, the engine and what you’ve already tried. We reply within 48 hours, and the questions that come up often become new guides.