Howdy folks. I’ve got an ‘89 Merc 115 4-cyl. I’m having some acceleration issues with it. I pulled all the carbs today and cleaned them with an ultrasonic cleaner and then blasted them out with carb cleaner and compressed air. It’s idling a little higher now than before, but starts immediately and will idle smooth. Shifts in and out of gear with no problem. When I apply throttle, I’d say about 1/3, it acts like it’s bogging down. If I hold it there for a few seconds and then go to 3/4 throttle, it’ll hesitate briefly and then take off with no issue. It’ll run WOT all day. If I try to go from idle to wide open quickly, it’ll bog and die with a cloud of smoke like it’s over-fueling. From my understanding these motors operate with 2 carbs at idle and the other 2 kick in at a higher rpm. Could there be something causing a bad transition from 2 to 4 carbs? The carbs and fuel pump were recently rebuilt and I’ve replaced the fuel lines/primer, spark plugs, and fuel filter. Running 90 octane non-ethanol 50:1 (oil injection has been removed.) All pistons and spark plugs are clean as a whistle.
