75-JOHNSON
Seaman
- Joined
- Jul 2, 2009
- Messages
- 55
all three cylinders have spark, timing is correct,110psi on all 3, can run on middle and bottom cylinders fine. switched the #1 and #3 carbs and the top cylinder still wont fire, leads me to beleive its not a carb issue. just backfires and sputters. service manual is on its way but does anyone have any advice as to what might be wrong? something with the reed valves??