正定县七吉村小王有台小四轮拖拉机 ,一年烧了八次瓦。为什么 ?经我们俩共同分析认为有以下原因 :一、机油内杂质过多　小王常年往工地上送砂子 ,外部环境恶劣 ,本人又不注意机油清洁 ,随便存放机油且油桶不加盖 ,对机油滤清器很少按时保养清洗。随地拆修机子 ,尘土直接侵入轴? Small village in Qidi Village, Zhengding County, has a small four-wheel tractor that burns eight tiles a year. Why? By our common analysis that the following reasons: First, too much impurities in the oil Wang sent perennial sand to the site, the external environment is poor, I do not pay attention to oil clean, casually stored oil and oil drums without cap, right Oil filter rarely timely maintenance cleaning. Overhaul machine, dust directly invaded the shaft?