Re: 1989 70HP Merc pops back Back fires) lightly only once and awhile while idling
Captain Curt,
I'm thinking you may have a lean sneeze due to a dirty low speed circuit, which a carb cleaning should cure. If you do, go with new carb kits, particularly new needles and seats (have a problem with those myself). Has it been a while since the carbs were cleaned, or has the motor sat for a long time without being used? If so, I'd go with new fuel lines and carb cleaning whether it needs it or not.... Then again, I'm no expert by a long shot, particularly on mercs. I am Kind of wondering about your "outlet to fuel pump" backfire...? I'm not sure what you mean, but it doesn't sound good for your fuel pump diaphragm!
JBJ
