Lawn Mower Won't Start

Learn the reasons why a lawn mower won't offset afterward winter or during peak season, and how to fix those problems.

Introduction

Most of the time when a lawn mower won't start the cause is a problem with the gas or the lawn mower carburetor.

Tools Required

Materials Required

  • Carburetor cleaner
  • Carburetor or carburetor inlet needle and seat
  • Gasoline

Lawn Mower Won't Start After Wintertime?

Whether you've got a Toro backyard mower, a Briggs and Stratton backyard mower, or one of the other popular brands, the terminal thing you want one time winter finally lifts and bound has sprung is a lawn mower that won't start.

Before you have a heart set on pulling on the rip string, you'll want to bank check the fuel, equally well as the lawn mower carburetor. They're the root causes of more than 80% of all backyard mowers that won't start (plus snow blowers and nigh small engines in general). Below, we'll walk yous through the steps of how to commencement a lawn mower when it's giving you grief. Check out how to tune up a lawn mower, besides.

You'll need manus tools and a socket set up, a can of carburetor cleaner and your air compressor to begin fixing a lawn mower that won't start. And you'll probably have to make a trip to the small-engine parts store. But afterwards an hr of effort, yous simply might accept an operational engine, and you'll save a bundle past fixing it yourself. Let'due south dig in to see what to do when a mower won't showtime.

Check the plug

I'll assume you've cleaned the air filter, and then the next footstep is to remove the spark plug to run into if it'due south wet. If it is, there's no way the engine will offset. So clean the plug with carburetor cleaner and permit it dry. Cleaning it with compressed air isn't enough; you lot need a solvent to remove oil balance. If the plug was wet, move on to Stride iii. If it was dry, skip to Step 4. If the fuel is more than than a month one-time, dispose of it properly and refill the tank with fresh gas. Then reinstall the spark plug and try starting. Information technology may have quite a few pulls to suck the new gas into the lawn mower carburetor, and so be prepared to clean and dry the plug a few more times.

Project step-by-step (5)

Step ane

Check the carburetor bowl for gas

Remove the basin

bowl

Gear up a small cup under the lawn mower carburetor to catch any spills. Then loosen the bowl nut with a socket. One time the nut is loose, unscrew it past hand and lower the basin. Gas should baste out.

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Footstep 2

Remove the inlet needle and seat

inlet

Pull the float pin straight out. Grab the bladder, inlet needle and retaining bound with a rag. Remove the safe seat with a small choice. Contrary the procedure to install the new parts.

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Stride 3

Check carb condition

condition

Examine the within of the backyard mower carburetor. If yous run across chalky/powdery white corrosion like this, the carb is a goner.

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Step iv

Fellow DIYer's solution for corroded carburetor

An bearding reader from Oakland, ME took upshot with my statement that finding corrosion in a small engine carburetor means "game over." Instead he advises humid the disassembled carburetor in vinegar for thirty minutes. He says the pitting will remain, but the vinegar will remove the remainder of the corrosion. Since vinegar is inexpensive, you've got zip to lose simply fourth dimension.

The engine tin can't go gas if the fuel filter is plugged or the carburetor inlet needle is stuck. Check the fuel filter (if equipped) past removing the fuel line at the carburetor. Gas should run out. If it doesn't, remove the fuel line ahead of the fuel filter inlet. If gas flows, the filter is clogged. Supersede information technology. If you still don't get any gas, the fuel line is kinked or plugged. And check inside the tank for whatever debris that might clog the outlet.

If you're getting gas to the lawn mower carburetor, check to run into if in that location's any fuel in the basin. Clamp off the fuel line with a C-clench. Then remove the bowl (Photo 1). If the basin is empty, the problem is a stuck inlet needle and seat. They're easy and inexpensive to supplant (Photo ii). But earlier yous buy the parts, check the status of the balance of the carburetor'south interior (Photo iii). If you see any corrosion, it'south "game over." A corroded lawn mower carburetor is a dead carburetor. Replace information technology.

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Footstep five

Make clean the jet

Make clean the main jet

Clean

Remove the carburetor bowl nut. Insert the carburetor cleaner straw directly into the main jet passage and squeeze the trigger on the tin can several times until the spray shoots into the venturi of the carburetor. That'll ostend the passage is open. A chock-full chief jet is a pretty common problem. You tin try cleaning it with spray carburetor cleaner (Photo 4). So try starting. If the engine nevertheless isn't getting gas, supercede the carburetor.

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If it starts simply runs crude

If you got the engine to start by cleaning the main jet, but it runs rough or the idle speed surges, you lot have ii choices—rebuild or replace the lawn mower carburetor. For rebuilding instructions, see "How to repair small engines." Otherwise, disconnect the old backyard mower carburetor from the linkage, remove the two retaining bolts and slap on a new carburetor.

Lawn Mower Won't Start

Originally Published: June 03, 2019