Echo Won't Start: What to Check, In Order

The order is not arbitrary. Each step is cheaper and faster than the next, and each one rules out a fault that mimics the ones below it.

This whole order assumes the engine turns over normally when you pull the cord. If the cord itself pulls with no resistance, will not return, or has snapped, that is a different fault entirely - see Echo recoil starter and pull cord before working through the list above.

The order above does not change with the model. Echo built its 21.2 cc handhelds around one engine, so an SRM-225, a GT-225, a PAS-225 power head, a PE-225 edger and an SHC-225 shaft hedger all fail - and start - for the same reasons in the same sequence. If a weed eater on this engine will not start, fuel age is still the first suspect, not the carburettor.

The one part that does not cross the family is the carburettor. The 225 group runs the Walbro RB-K93; the older SRM-210 and SRM-230 run a different Zama unit - so if you do reach step five, order by engine family and not by the badge. Both groups share the air filter A226001410 and the same 50:1 mix. Full fitment is on the SRM-225 parts and SRM-210 parts pages; which carburettor fits which family is on the carburettor page.

Petrol containing ethanol goes stale in weeks. It absorbs water, separates, and leaves a varnish through the fuel system that blocks the very small passages inside a two-stroke carburettor. A machine that ran fine in October and will not start in April almost always has this and nothing else.

Empty the tank completely - do not top it up. Mix fresh fuel at the ratio in your manual; Echo's Power Blend is 50:1, part 6450050 for the gallon bottle. Then try again before touching anything else.

If you are unsure which oil your Echo takes and how to mix it, that is covered on its own page.

Storing a machine with fuel in it is what creates this, and running it dry before storage avoids it entirely.

The same order applies to Echo's CS-series chainsaws, which run the identical two-stroke engine - if a saw cranks and starts but cuts slowly or not at all, the fault is the chain and bar, not the fuel system.

It applies to Echo's backpack blowers too, which sit unused for longer stretches than a trimmer and so are more likely to have stale fuel behind a no-start - see blower parts for what else is family-specific on those.

Fuel lines and primer bulbs age whether or not the machine is used. They go hard, then crack, usually where the line enters the tank or the bulb meets its seat. A cracked line draws air rather than fuel, so the engine gets a mixture it cannot run on no matter how much you prime.

The tell is the primer bulb. If it will not fill, or fills and then goes soft again, the fuel system is drawing air. If it fills and stays firm and the machine still will not start, the fault is elsewhere.

The in-tank fuel filter belongs to this group too. It is the small weighted cylinder on the end of the pickup line, it clogs invisibly, and it produces a machine that idles happily then dies the moment you open the throttle. Tune-up kits for the 225 family bundle all three.

On the older Echo SRM-210 the order is the same - stale fuel and perished lines first, the carburettor last.

The genuine primer bulb number and which models actually share it are on the Echo primer bulb page.

The genuine in-tank fuel filter number - and the older generation that does not match the current one - is on the Echo fuel filter page.

Pull the plug and look at it before replacing it, because it reports on the rest of the engine.

• Wet with fuel - flooded. Leave the plug out, pull the starter several times to clear the cylinder, dry the plug, refit.
• Black and sooty - running rich. Suspect the air filter first, then the mixture setting.
• Light grey or white - running lean. Worth investigating before it costs you a piston.
• Light brown - correct.

To test for spark, refit the plug in its cap, hold the metal body against the cylinder and pull the starter. A visible blue spark at the tip means the ignition side is fine.

If the plug itself turns out to be the problem, the genuine number depends on which engine family you have - see the Echo spark plug page for the numbers by model.

If fuel is fresh, the filter is clean, the lines and bulb are sound and there is a good spark, the carburettor is a fair suspect. Even then, a strip and clean with a new diaphragm kit fixes more of these than a replacement does - the failure is nearly always varnish and hardened diaphragms rather than anything broken.

See carburettors and fitment for what fits which engine family and when replacing genuinely makes sense.

A spark test that comes back completely dead - not weak, not intermittent, nothing at all - points past the plug and cap to the coil itself; see Echo ignition coil numbers by engine for the right part by model family.