SparkieBoat
Captain
- Joined
- Aug 17, 2009
- Messages
- 3,643
I have a 1993 40 HP yamaha outboard. C40MSHR. I have repeatedly cleaned both carbs and paid particular attention to my bottom carbs needle valve assembly and passage. When I put it all back together and take it to the river it runs great for a while then begins to run on 1 cylinder. I pulled the plug wires and when I pull the bottom one there is no change when it is acting up. so it must be my bottom carb. It seems like it is starving for fuel. but when I get home and take it apart the valve does not seem to be stuck. sometimes I can pull the choke a few times while it is running and it may go back to running perfectly again. I cannot find any signs of trash in the fuel, fresh fuel in a clean can. I cannot understand what is going on. Any help appreciated.