Troubleshooting a lawn mower

[adan]

When a car engine won't start, there is a range of possible reasons and another range of possible solutions. One would start looking at the fuel gauge. If fuel is not the issue, then the battery, and so on and so forth.

How do you do it with lawnmowers that don't start properly? What is the checklist of things to inspect in order of importance?

 

[KennyV]

Fuel, spark (for gasoline engines) and air...
Clean, in the right quantity and at the right time....
Most small engine problems are fuel related... :smile:KennyV

 

[Dannie]

Small engines are the same as the big ones.FUEL, SPARK, compression.No fuel check fuel filters,lines ,cap,carburator,no spark check plug,coil,flywheel key,ignition switch,safety switchs.No compression head gasket,valves,rings.There are some good books on the repair of small engines,after 42 years of repairing them I know a little.Everone has to start someplace go to it.

 

[adan]

Thanks for the insight that small engine problems are fuel-related. For some reason that's a relief.

My first car was a used one. I think I was the 3rd or 4th owner. It ran well, except in few situations where I had to deal with electrical connection to the battery and choking. My experiences with that car would be useful in dealing with lawn mowers

 

[junebug1701]

Remember FACES when working on an engine. For the engine to run you need:

Fuel - Check tank, filter, lines, clean carburetor, etc.
Air - Clean or replace air filter element.
Compression - Use a compression tester - 50+ psi on a 4-stroke, 100+ on a 2-stroke.
Exhaust - Make sure the muffler/spark arrestor is free of carbon build-up (2-stroke).
Spark - Look for a healthy spark, replace plug with a new one if in doubt.

 

[adan]

Hi Junebag! Now that's the one I was looking for, a mnemonic that makes things more systematic mentally. I mean, I don't imagine myself holding a manual when such time comes

 

[JDgreen]

When a car engine won't start, there is a range of possible reasons and another range of possible solutions. One would start looking at the fuel gauge. If fuel is not the issue, then the battery, and so on and so forth.

How do you do it with lawnmowers that don't start properly? What is the checklist of things to inspect in order of importance?

Fuel first, check for level and that it's not stale gas. Second, be sure the plug wire is on the plug tight. Third, and nobody mentioned this, be sure the safety shut off controls are working properly. As a mower (walk behind especailly) ages, the cable and lever for the handlebar bail that keeps the engine running until you release it, can malfunction. If the cable stretches enough, the mower will get no spark. I've had this problem on several of my pushers. Usually there is no way to adjust the connection on the engine, but you can easily rig a way to make the cable pull further as a test method. Mine is to use a pair of pliers on the wire at the handle control.

For riders and tractors, most or all have safety switches, if you turn the key and no cranking, it's a battery issue of malfunctioning safety control.

But in my situations, it's almost always fuel related. Want to pass along a story...my sister in law has a 2001 Buick, she was heading to work last week and the car died. She paid $70 for a tow, and they put gas in her car and it started right up...get this, the fuel gauge was defective and she knew it, but she never considered she might just be out of gas. She is lucky the shop was honest, they could have told her the fuel pump was bad and charged her $700 for a repair she didn't need.

 

[adan]

Want to pass along a story...my sister in law has a 2001 Buick, she was heading to work last week and the car died. She paid $70 for a tow, and they put gas in her car and it started right up...get this, the fuel gauge was defective and she knew it, but she never considered she might just be out of gas. She is lucky the shop was honest, they could have told her the fuel pump was bad and charged her $700 for a repair she didn't need.

A defective fuel gauge is the one that frightens me the most. Your sister-in-law is very lucky indeed that she chanced upon an honest shop.

I asked a shop to fix a very minor thing on my car at one time. This bubbly guy fixed it, but his bubbliness all of a sudden was about how I needed to fix this and to fix that, and if I didn't do it immediately this or that would happen to the car, bla, bla, bla. I left that shop totally shocked at how some people could be brazenly dishonest just to earn a few bucks.

 

[Mean Machine]

If it won't crank there are a few things to check: make sure the the mowing deck is not engaged, make sure parking brake is off, check safety switches, check battery, check fuses, check for loose wires, or check ground wire.

 

[mois25]

An insightful thread indeed. There are instances when the engine wont start or is hard to start. One reason could be that there is water in the fuel whose cause could be breaker points are pitted or improperly gagged or the condenser is bad.