not realy woried about it working well just enough to move it in and out of shed till i can get cash together for a rebuild and oem carbs just chucked carb had lying around of avenger on it to get it to fire all fuel is coming out over flow on carb due to to high fuel pressure i believe but cant wind down any lower on fpr. just realy want to know about the back fire threw breather hose would this be from firing before intake valves close? not much ajustment on dizzy so maybe i mised a tooth