Won't idle without choke after storage: varnished carb
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Applies to: Any carbureted machine (All brands), Any year that sat with fuel
Symptoms
- Sat for months, now won't start or only runs on choke
- Dies when you open the throttle
- Bogs, hesitates, runs rough
Why it happens
E10 fuel goes stale in 30–60 days and leaves sticky varnish in the jets. The pilot (idle) jet is the smallest, so it clogs first, which is why it only runs on choke.
How to fix it
- Drain the tank and refill with fresh fuel.
- Open the float bowl drain screws.
- If still bad: remove and strip the carb, soak in cleaner.
- Clear the pilot jet with a fine wire strand; cleaner alone often won't.
- Blow out every passage and reassemble with new O-rings / gaskets, or fit a rebuild kit.
Tools and parts
- Carb cleaner
- Fine wire
- Compressed air
- Carb rebuild kit
- Fuel stabilizer
What the factory service manual covers
Carburetor: exploded view, jet sizes, float height, idle mixture settings. The full procedure, specs and wiring diagrams are in the factory service manual for your machine.