??? How big do I drill the jet?The carbs on those engines are terrible!!
They get clogged & (I have found) them to be near impossible to get them to idle again!!!!
This is why so many switch to the NT 2-stroke carb & manifold.
Keep in mind that you'll have to drill the NT jet a little bigger for the 4-stroke engine.
Here's a link to the parts...
Whenever I build a 49cc 4-stroke bike, these automatically go on it!!!!