I recently purchased a used os 40fp and noticed when running it fuel seems to spit out of the base of the main needle. In other engines I have there are one or more rubber o-rings around the need which can be seen once the needle is removed from the carb. The carb in question is a 3A. Has anyone else got this carb/engine that can advise if the needle has an o-ring in it/on it as mine doesnt seem to have one fitted.

Adam.