I bought a ยด78 CB400T approx. 8 months ago. It had been stored in a barn for several yrs. I cleaned the rust from the pipes by applying Lime-away (thick formula)to cold pipes, agitating the bad spots with a stiff parts cleaning brush. Then rinsed pipes well, wiped dry and applied the process a second time. Then rinse, dry, and apply a third coat, let it set several minutes unagitated. Rinse and dry. I had no noticeable smoking pipes.