As previously mentioned read through this thread and you will find all of the tips and tricks. Yes it does take a long time to properly break-in and along the way you need to keep fiddling with the adjustments but when you get over the hump the engine comes alive and you will not have to touch the tuning much.

As far as a smoke system, I would be leery of it as the engine's carb really requires good pressure from the exhaust to run properly. I am not sure how the carb will react after injecting smoke fluid into the muffler to burn. If I were to experiment I would try it well after 3 gallons have been burned and it is well broken-in.