Anybody used a FLUID DAMPER on their engine before?

ryan04

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Jan 26, 2005
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Hey boys, I've got a 1996 4.3L Thunderbolt ignition Gen+ with an alpha one gen 2 drive. I was gonna pull the engine and swap the flywheel because I'm 99% sure it's the wrong one. Gonna sell the boat. It was on there when I bought the boat last year. So in turn I have a vibration at 2500 RPM. I'm thinking of something easy to reduce the vibration. The easiest is definitely using a fluid damper. Has anybody ever used one of these on a marine engine before? I'm hoping it will reduce the vibration from the wrong flywheel helping balance the engine more. My bearings are still ok, and it drives great, just the vibration at cruising speed. If you have which one should I get, brand and model number? Thoughts?
 

alldodge

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Hey boys, I've got a 1996 4.3L Thunderbolt ignition Gen+ with an alpha one gen 2 drive. I was gonna pull the engine and swap the flywheel because I'm 99% sure it's the wrong one. Gonna sell the boat. It was on there when I bought the boat last year. So in turn I have a vibration at 2500 RPM. I'm thinking of something easy to reduce the vibration. The easiest is definitely using a fluid damper. Has anybody ever used one of these on a marine engine before? I'm hoping it will reduce the vibration from the wrong flywheel helping balance the engine more. My bearings are still ok, and it drives great, just the vibration at cruising speed. If you have which one should I get, brand and model number? Thoughts?

I don't see a fluid damper to be the fix for a vibration issue. They can help in higher rpm range but above where your engine would normally operate. Why do you think it is the flywheel? Have you checked the plugs to see if one is not firing correctly?
 

mr 88

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Nov 3, 2010
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First time that I have heard of this one on a normal set up being the problem of a vibration. I agree with AllDodge. Could be a universal joint going,prop/prop shaft or some sort of a miss in the engine.. Try throwing a different prop on it and see what happens.
 

Bondo

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Ayuh,.... A Fluid Damper will Not rebalance, an out of balance motor,.....

What makes ya think ya got the wrong flywheel,..??
 

mr 88

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On top of that you have a 19 year old boat,if the vibration was there from day one I think one of the previous owners or the FIRST owner would of had that fixed from the get go. A flywheel doesn't suddenly go out of balance,its there from day one or it isn't,[unless a counter weight is thrown off,highly unlikely] Cracked flywheel would be another story and I do not think it would vibrate as much as it would clatter on start up and even that would be a constant vibration /noise through out the whole rpm range ,not just at 2500 .
 

ryan04

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Jan 26, 2005
Messages
212
The reason I think it's the flywheel is because I/and my mechanic, have ruled everything else out. From prop, to prop shaft, gimble bearing, u-joints, plugs, wires, timing, distributor, ignition coil, compression, and harmonic balancer. I had starting problems last year and replaced the starter and when I did I noticed it was a cheap aftermarket one that was in there. So when I noticed that I figured it's more than likely that the starter, ring gear, flywheel had been messed with. Now I know the ring gear is separate but I don't know the story from the previous guy, for all I know he had a buddy with a V8 flywheel kicking around and said it works no problems so they had it put on. I took it to my marine mechanic and he concluded the exact same thing. My thrust bearings/cam bearings are just inside the tolerance line for wear, so I'm at one of two things left. Either for some reason my timing chain skipped a tooth or is unaligned, (but i'd think that could be made up with rotating the distributor) or the flywheel is the wrong flywheel. I talked with a guy from australia who bought a used MPI and had it put in, and he had the exact same vibration at the exact same RPM's and he didn't know what was going on. He took it back to where he got the engine and they concluded it was the flywheel and swapped it out. Since then he said it's perfect now. So all of that combined, leads me to believe it's the flywheel. I buy and sell boats constantly, so I'm selling it anyway in the spring, but would like to calm the vibration first. I'd rather not pull the engine and swap the flywheel on a boat that i'm selling anyway. I also don't want to sell a piece of crap to somebody. Runs perfect except for a vibration at 2500-3000rpm. I like to sleep carefree! haha! Thoughts?
 
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