My 126 started to run a bit rough, and I noticed that there is a lot of oil seems to be getting sucked into the carb after a few minutes of running. The engine won't idle without choke, and it seems to have an inconsistent misfire to the point where it feels like it's on running on one cylinder.
Also someone has fitted a temporary washer on the spring of of the oil filler cap, could this allow oil to be sucked through to the carb?
Here are some pictures of inside the carb:


Could anyone be of any help? Thanks!