Mowers, generators, pressure washers and other four-stroke engines
The engines with their own oil. Spark, fuel and compression tests that apply to your machine whatever the brand.
Engine cranks but won't start
Engine turns over but never fires? Test spark, then fuel, then compression in the right order, and rule out stale gas, the kill circuit and a clogged carburetor.
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Engine won't crank or turn over
Pull cord won't pull, starter just clicks, or nothing happens when you turn the key? Tell a weak battery, a safety interlock, a bad solenoid or starter, and a seized engine apart.
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Engine starts, then dies
Runs for a few seconds or minutes, then quits? How it dies points straight at the cause: an air leak, a clogged jet, a blocked fuel-cap vent, overheating or a failing coil.
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Engine runs rough: surging, shaking, smoking or misfiring
Surging up and down, revving too high, shaking, smoking or misfiring? Work out which kind of rough it is first, then test the right system instead of guessing.
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Trimmers, blowers, chainsaws and other two-stroke equipment
The engines that run on mixed fuel. Fuel mix, fuel lines, the carburetor and the clutch come first here.
Weed eater, trimmer or chainsaw won't start or won't stay running
Two-stroke won't start, won't idle or dies at full throttle? Check the fuel mix, fuel lines, plug, spark-arrestor screen and carburetor in the order that finds it fastest.
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Trimmer or chainsaw runs rough: surging, bogging, vibrating, smoking or spinning at idle
Surging, bogging down, vibrating, smoking, or the chain or head spinning at idle? Find the cause, including the safety fault of an attachment that moves when it should be still.
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Weed eater or chainsaw starts, then dies
Starts fine but quits, or dies when you squeeze the trigger or start cutting? Separate an air leak, fuel starvation, heat and a slipping clutch before you touch the carburetor.
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Not sure which one is yours?
Tell the free guided diagnosis what your machine is doing and it picks the right tests, then names the part for your exact model when it can confirm one.