2007ish Honda activa doesn't start or idle without using the choke. It also bogs down or shuts off when giving 25% throttle (but runs fine with choke, tho it isn't good for the scooty) . I have tried making the fuel mixture richer, but it works only when running it at that point, basically next morning it again is a trouble to get it running without the choke, but I have noticed slight difference in the top end. It wasn't accelerating past 40Km/h but now it goes 60-65 (decent for a 100cc scooter I think)

Here is a reference image to what the carb looks like

the 2 goldish screws are what i tried adjusting (left seems to be mixture and right idle)

Any help would be appreciated!

1 Answer 1


The problem sounds like a fuel restriction, so adjusting the mixture screws isn't likely to improve things.

You could have a clogged fuel filter, although that is not particularly likely as your revs would be suffering.

The most likely culprit is your carb fuel jet(s) is clogged. You may be able to clean the gunk out with some carb cleaner spray without removing the carb, or by running a tank with some fuel system cleaner. However, you may end up needing to take the carb off and strip it down for a good clean. There's no harm in trying a cleaner first, you'll need it anyway if you need to strip it later.

Once it is clean you'll need to tune it again. Also, if you take off the carb make sure you cover the hole to prevent debris or bugs from getting in.

  • You are probably right about your first point since it is already running in the richest possible mix, anything richer wont let me fire the engine. But it still needs choke during a cold start. The carb was recently cleaned by a FNG Mechanic, maybe improper instalment could cause some sort of airleak? I will still try out the cleaner Jun 29, 2023 at 14:05

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