navcon@cfl.rr.com
Cadet
- Joined
- Jul 26, 2007
- Messages
- 6
I have a 2005 5.0 Volvo Penta OSi-E, with 130 hours on it. Had standard 100 service done at 90 hours. After 1 or 2 hours of running at 4000 rpm (25 mph) the engine begins backfiring (pop, pop, pop). It loses about 200-300 rpm immediately before the backfire and then returns to normal operation after the backfire for about 15 seconds - then it happens again. The problem never happens at idle/no wake speeds (i.e. it can be backfiring, but if I bring if off plane it runs fine). The next morning the boat runs fine for 1-2 hours and the whole thing repeats again. I have replaced the fuel/water separators twice and had the tank checked for water/debris by a pro - no water in the fuel. I took it in to my mechanic and the engine returned no error codes. Any thoughts?
