So I finally got my first mild engine build completed and when I fired it up for the first time a few nights ago, I noted that it would occasionally fire out sparks or a very short flame from the header. Is this an indication that I need to jet up? Or is this a timing issue? I believe that the timing should be just fine and I thought that sometimes this can happen if an engine is running too lean, is that correct or am I way off base?
Perhaps some more information would be beneficial. I removed governor, added arc rod and arc flywheel. I pulled off the muffler and put on an open header. I pulled off the stock carb and air filter setup and put on an animal carb (PZ22, very similar to a 22mm Mikuni). I have a #92 jet in the carb. I also am running a high flow air filter on the carb. I do not know that I can take an accurate plug reading yet since I do not have it mounted to a bike.
I'd put at least a 100 main in it and if it's boggy during acceleration drop the needle clip a notch or two, this will richen up low to upper mid range... If the 100 is too rich you can drop it down but it's safer to be rich than lean..
Also make sure you don't have a leak at the header gasket, that will cause a flame (pop) but usually on deceleration when it draws air in around the gasket..
Also make sure you don't have a leak at the header gasket, that will cause a flame (pop) but usually on deceleration when it draws air in around the gasket..