Grand Larsony
Member
- Joined
- Jul 29, 2005
- RO Number
- 18485
- Messages
- 155
[Edited to clarify]
Upon inspecting the bellows in my lower unit (1989 Alpha 1, Merc 260350 single on Larson San Marino), I noticed something VERY concerning...
My lower bellows (the large one for exhaust) was completely torn out at the rear hose clamps (everything was new last season). I also found what I expect is an exhaust flapper inside. It was about 2.5" x 1.5" and oval in shape.
Could this have caused serious vibration during my last use? It started fine, idled out fine, came up on plane, but then began to shudder violently as if the engine was either misfiring or I had one blade on the prop. I backed right down and checked things out. When going back into gear (carefully), it happened again immediately but was fine at idle and out of gear. Luckily I was right off my dock and limped in.
Called mechanic from dock, who had last driven boat and he said "oh, yeah... that's the thingy in the power steering. Leave it a day and it will be fine once it resets itself." ... and when he came the next day with me to check it out, it actually was fine! I was skeptical, but what could I do? He was very confident in his diagnosis.
Is it possible that the problem I had was the exhaust flapper blowing out? I did not hear anything ticking beforehand, and the boat didn't sink in the two plus weeks it was in the water afterwards. He drove it to the pullout ramp and said it was fine.
He didn't shoot the bottom for days, either, and then blew off all my new bottom paint. Another story...
Upon inspecting the bellows in my lower unit (1989 Alpha 1, Merc 260350 single on Larson San Marino), I noticed something VERY concerning...
My lower bellows (the large one for exhaust) was completely torn out at the rear hose clamps (everything was new last season). I also found what I expect is an exhaust flapper inside. It was about 2.5" x 1.5" and oval in shape.
Could this have caused serious vibration during my last use? It started fine, idled out fine, came up on plane, but then began to shudder violently as if the engine was either misfiring or I had one blade on the prop. I backed right down and checked things out. When going back into gear (carefully), it happened again immediately but was fine at idle and out of gear. Luckily I was right off my dock and limped in.
Called mechanic from dock, who had last driven boat and he said "oh, yeah... that's the thingy in the power steering. Leave it a day and it will be fine once it resets itself." ... and when he came the next day with me to check it out, it actually was fine! I was skeptical, but what could I do? He was very confident in his diagnosis.
Is it possible that the problem I had was the exhaust flapper blowing out? I did not hear anything ticking beforehand, and the boat didn't sink in the two plus weeks it was in the water afterwards. He drove it to the pullout ramp and said it was fine.
He didn't shoot the bottom for days, either, and then blew off all my new bottom paint. Another story...