Thanks guys, I'll try lapping as the next step - any specific compound/grit? I have the permatex stuff that comes in a jar but it feels very coarse. Not sure if these little heads call for something finer?
Yup, I pulled the intake tube off before touching the carb. With cold starts I'm used to a film of unburnt fuel on the walls but never dripping. I know some bikes/engines act differently when cold so it could well be a non-issue.
As an experiment I again tried to go completely lean by dropping the needle all the way (clip in the top most grove), setting float to the lowest possible position before it stops filling bowl completely, and pulling the air filter. Still guzzles tons of gas and smokes like hell. Mixture screw has no effect unless it's screwed all the way in.
As for the liquid fuel you found, are you 100% certain that wasn't a result of fuel slosh + spillage from removing the carb?
Yup, I pulled the intake tube off before touching the carb. With cold starts I'm used to a film of unburnt fuel on the walls but never dripping. I know some bikes/engines act differently when cold so it could well be a non-issue.
As an experiment I again tried to go completely lean by dropping the needle all the way (clip in the top most grove), setting float to the lowest possible position before it stops filling bowl completely, and pulling the air filter. Still guzzles tons of gas and smokes like hell. Mixture screw has no effect unless it's screwed all the way in.