I have a Karcher pressure washer with a Honda GCV160 engine that won't start. The only time I have a some success is when I put a little gas in the spark plug hole and then it runs for a few seconds and cuts out. I have spark. Fuel valve is open. All lines are clear. I cleaned the carb. Everything is clear. The Air filter is clean. There is gas. The oil is at the right level. The kill switch is on. I ran it with water . I pumped the wand trigger three times to relieve pressure. This is an older machine which has been used once or twice and has sat in a garage for about 5 years. What am I doing wrong and where should I go from here? Any help would be appreciative. Thanks.