If the light is on and you have spark, it's not very likely there's any trouble with the switch.
It's more likely a fuel thing, or possibly your "electric starter" isn't turning the engine over fast enough.
When you pull the plug, is it wet? Possible fouled with raw gas?
If the plug is dry, have you tried priming the engine with a few drops of fuel? The carbs, until they've had some fuel run through them, don't pump worth a darn, Guys writing in trying to get that initial carb prime and start out of the way frequently struggle with that first start because of that.