vstk
Guest
The venturi on the exhaust is bad.......change it and replace the steel line with a hose intended for asperator lines.........they work better. One other possiblity is the flapper in the aircleaner housing is broken or stuck. There is a one way valve (so to speak) that keeps exhaust gas from getting into the air cleaner under low RPM's when the apserator isnt sucking. You should be able to inspect both and know pretty quick which it is.........could be both. Van