Re: exhaust bellow separation trip this weekend
2000 Mercruiser 4.3 Alpha Gen II
Make your exhaust bellows purchase carefully. This May I replaced my bellows including the exhaust bellows using Sierra as recommended by my local Mercruiser dealer. Here's what I ended up with. Lasted maybe 10 operating hours. Suggestion: DO NOT USE SIERRA EXHAUST BELLOWS 18-2750. I decided to try a Mallory 9-72730 Exhaust Bellows this time around. I'll post my observations if I have any problems.
[Aug-23-2012]
The Mallory Exhaust Bellows is still in good shape. No problems with it yet. An installation tip that might be helpful - Make sure the parting seam in your exhaust bellows is clocked horizontally, that is, the seam is visible when looking at it from the sides. The Sierra one I put in I disregarded the clocking of it and suspect it came apart along the parting seam. I looked at a friends (old) boat and noted the exhaust bellows was clocked horizontally, seemingly intentionally. I made sure the Mallory's seam was clocked to horizontal when I installed it and so far so good. I haven't ever run across any recommendation for clocking the seam, so this is strictly a *maybe* tip, but its also one that one that won't cost a cent and might be that extra little bit to help your exhaust bellows live a long life.