Brass Monkey
Member
- Joined
- Mar 15, 2005
- RO Number
- 16606
- Messages
- 50
1991 Bayliner 3058 CB, twin 4.3L engines, Alpha I. Port has 300 hours, STBD has 100. Drives pulled in March, shafts lubed (looked great), shafts balanced into engine mounts, oil changed then. One oil change two weeks ago at 60 hours since the March service. Port coil replaced at that time.
Running home this afternoon, the STBD tach starts bouncing up and down 1.5-2K, and the engine sounds like it is matching what the tach says (READ: it doesn't seem like a cheap tach issue). It sounds like it is cavitating, but I'm not really in a situation where that should be happening. STBD is solid at 3600rpms the entire time, and I stay on plane fine for the last half hour home to the marina. Props look OK on inspection underwater (I can trailer them to within a few inches of the water surface).
Summary: Running home at 36-3700 rpm, on plane, port tach begins bouncing from 35-3800 in synch with an increase/decrease in engine noise. Everything else seems fine.
I'm calling for the mechanic tomorrow, but your thoughts?
Thanks.
Running home this afternoon, the STBD tach starts bouncing up and down 1.5-2K, and the engine sounds like it is matching what the tach says (READ: it doesn't seem like a cheap tach issue). It sounds like it is cavitating, but I'm not really in a situation where that should be happening. STBD is solid at 3600rpms the entire time, and I stay on plane fine for the last half hour home to the marina. Props look OK on inspection underwater (I can trailer them to within a few inches of the water surface).
Summary: Running home at 36-3700 rpm, on plane, port tach begins bouncing from 35-3800 in synch with an increase/decrease in engine noise. Everything else seems fine.
I'm calling for the mechanic tomorrow, but your thoughts?
Thanks.