由于排汽凸轮盘不正确的定时或排汽系统背压过大（背压不能超过300毫米水柱）而导致燃气通过扫气口倒流。

C. Blow-back through the scavenge air ports, owing to an incorrectly adjusted exhaust cam disc or large resistance in the exhaust system(back pressure not exceed 300 mm wc)

youdao

由于排汽凸轮盘不正确的定时或排汽系统背压过大（背压不能超过300毫米水柱）而导致燃气通过扫气口倒流。

C. Blow-back through the scavenge air ports, owing to an incorrectly adjusted exhaust cam disc or large resistance in the exhaust system(back pressure not exceed 300 mm wc)

youdao