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Old 02-01-2014, 06:27 PM
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I have a new to me 99 Baja 302 Boss with twin 454 Mag MPIs turning Mirage Plus 25s. Idling it sounds and feels perfect. In and out of the water (on a hose). Took it around the lake for a couple hours everything was as it should be. Stopped to float for a little bit, when we began to take off the boat shuddered, is the best way to describe it. I backed off the throttles and the shudder stopped. Tried it again and it acted just fine. Nothing else remarkable that day. A week later idled out of the channel into the bay began to take off and the starboard engine shuddered horribly. It felt like a displaced u joint, it was that bad. I backed off and idled the rest of the short trip.
I have removed the out drives and the u joints seem to be in 100% condition (the dealer said all maintenance was done but I was skeptical). The prop hubs are not new. And that is on the list to change.

Does anyone have any suggestions as to what I should be looking for?

Thanks in advance.
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Old 02-01-2014, 06:35 PM
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Sounds like maybe a drive coupler getting ready to go have you ever smelled rubber burning?
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Old 02-01-2014, 06:39 PM
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No smells, but I will take a look in the morning. Any thoughts on the best way to do that? Thanks
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Old 02-01-2014, 06:43 PM
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If you can reach around and feel if the rubber is pushed out or torn. If not a mirror and a flashlight.
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Old 02-01-2014, 06:47 PM
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Ok, thanks a lot.
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Old 02-01-2014, 06:50 PM
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Sure one of your props isnt messed up?

Also, pull the props and make sure an old dock line isnt wrapped around the shaft.
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Old 02-01-2014, 07:04 PM
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The props are in good condition. No lines or any foreign material around the shafts. The hubs seem to be a little loose but I intend to replace them soon.
Could .015" clearance between the hub insert and spline adaptor cause the above condition?
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Old 02-01-2014, 11:51 PM
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This happened to me on my prop hub . I think it's called flo torq . If you have one make sure the plastic shim things are there. Mine did same thing and I had one on it replaced all four and never did it again. Just a thought
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Old 02-02-2014, 07:53 AM
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Did you try running only your port or starboard side in gear at a time to try an isolate your condition?
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Old 02-02-2014, 09:03 AM
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I did attempt to isolate the problem. No luck that way, everything seemed to be OK.
Although I was able to I visually inspect the starboard coupler through the gimbal bearing. I can see a definite delineation where the rubber meets the metal insert.

Now I am going to attempt to change the coupler without pulling the motor out. Fun fun!!
I really appreciate the input!
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