ORIGINAL: john leigh
i have about half an inch between the carb and the cowl, no hole cut but there is a lage hole cut around the exhasust to let air out, i have no more holes cut then others have on theres, that i have seen on this forum. the tube is not in the fuse. it is facing back to the fuse but in the engine bay about 6 to 7 inches long.
A half inch may not be enough distance from the carb to the cowling. If I remember correctly my DA 100 manual recommends one and one half inch distance minimum.
A friend had this problem on a Sachs 4.2 in a biplane. He cut a one inch diameter hole in the cowling in line with the carb inlet and the problem went away.