Generator won't start after sitting in the shed all winter — carb or something else?

Had the exact same drama last spring with my Honda EU22i — pulled the cord about forty times before admitting defeat and actually looking into it properly.

Nine times out of ten with a winter-stored generator it's the carburettor. Petrol goes stale surprisingly fast, and the lighter fractions evaporate leaving a varnish-like residue that gums up the tiny jets. You'll usually smell it when you drain the float bowl — that slightly sweet, almost lacquer-y smell is the giveaway.

My process now:

1. Drain the fuel — old petrol out completely
2. Carb cleaner spray through the jets (WD-40 do a decent one, readily available at most motor factors)
3. Fresh fuel — I use Aspen 4T alkylate petrol now, far more stable for storage
4. Check the spark plug — replace it if there's any doubt, they're a couple of quid

If the carb cleaner doesn't sort it, a full carb strip-and-soak isn't as daunting as it sounds. YouTube has brilliant walk-throughs for most common generators.

One thing people overlook — the air filter. A damp, clogged filter after winter storage can make a generator act like it's got fuel problems when actually it's just starving for air.

What generator are you running? Some of the cheaper inverter units (I've seen a few Einhell and Hyundai units come up on here) have carbs that are a bit more fiddly to access than the Honda or Yamaha equivalents.

Worth ruling out the simple stuff before assuming it's something more serious. What have you tried so far?

@PaddyDavies the tenth time is always a blocked main jet from stale petrol going gummy 😅

Classic winter storage crime. Drain the float bowl first — there's usually a little brass screw on the bottom of the carb. If the fuel coming out looks like varnish, that's your culprit.

Soak the jet in carb cleaner overnight, blow through with compressed air, reassemble. 9/10 that's it sorted.

Also worth checking:

• Spark plug (cheap, just swap it)
• Air filter (moths love these apparently)
• Fuel tap in reserve position

I learned all this the hard way with my Kipor sat outside my cabin last March. Two hours of swearing vs. fifteen minutes of actual diagnosis. Methodical beats frantic every time, reluctant as I am to admit it.

@PaddyDavies @Curly38 — both solid points, and worth adding: don't overlook the spark plug. After a long winter sit, even a slightly fouled plug can cause that exact "pulls but won't fire" symptom. Cheap to replace and takes two minutes.

Also check the fuel valve is actually open — embarrassingly common one that.

If you do end up stripping the carb, a proper ultrasonic cleaner makes a huge difference versus just spraying carb cleaner through it. Transformed my old Briggs unit.

Welcome to the forum by the way — great first post, really detailed. Plenty of generator knowledge floating around here, so don't hesitate to ask follow-up questions once you've diagnosed it further. These EU22i units are generally very reliable once sorted, well worth putting the effort in rather than replacing it.

@BrambleElla already nabbed the plug point, so I'll add: drain the float bowl before storage next time — that gummy varnish everyone's describing is just petrol that sat there oxidising all winter like a pensioner in a deckchair. Spray some carb cleaner up the main jet, check your pilot jet too (tiny hole, massive drama when blocked), and if the choke butterfly isn't seating properly you'll be pulling that cord until your arm falls off. My Honda GX-powered unit lives on Aspen 4 alkylate fuel now — pricier than pump petrol but it genuinely doesn't go stale the same way, and it started first pull after eight months in my cabin shed last March.

@SussexSolar draining the float bowl is the move — wish I'd done that before I left my Honda sitting over winter at the cabin.

One thing nobody's mentioned yet: fresh fuel matters more than people think. Old E10 petrol goes off surprisingly fast — 30 days and it's already degrading. Grab some Aspen alkylate fuel for storage use, it's ethanol-free and stays stable for years. Bit pricier but I've not had a carb issue since switching.

Also worth checking the air filter if it's been sitting in a damp shed — mice love nesting in those things 🐭