Knocking and vibrations
 

Well, 2nd day out this year and my 7.4/454 1995 Talari has some serous issues. It starts up just fine and no problems at idle. As soon I I get to 2000+ RPM's it sounds awful. Thought is was the u-joints on the bravo 3 but now I think it my be both u-joints and a rod in the motor. Anyone have any advice? Going to take off the bravo 3 this week or weekend to check things out there. Maybe my knock is only there but it sounds crazy bad past 2K RPM and I suspect engine issues as well. 326 hours on the boat and motor but usually under full load of capacity and 4500/4800 RPMS. I made it back to dock under its own power but at only 1500 RPM. Pontoons even passed me, GRRRrrrrrr.

I would also be interested in where to buy a new long block. It changing the engine in a boat extremely difficult? I am pretty good mechanically, put a small block in a Toyota 4x4 back in my youth. Where is a reasonable place to buy a engine. I would love to go with a HP 396 or 427 but dont know the differences of what a boat will accept compared to a car/truck.

Appreciate the read and any advice. Can't imagine getting rid of my Mariah so I am looking forward to advice and encouragement. A little hoppy cam with the captains call would make the Baja folks jealous.

Re: Knocking and vibrations
 

Your symptoms sound similar to what I experienced a few years ago. I did the same as you, came back to port under my own power at about 1500 rpm (about a 10 mile cruise). Mine ended up being a blown head gasket between cylinders 6 and 8. A quick way of checking is by doing a compression check. I had sever cylinder scoring on the 2 cylinders and decided to go the long block route rather than over boring. Went with the same 5.7L as the boat had come with originally. Sorry can't help you with sourcing a long block as my local mechanic sourced it for me.

Re: Knocking and vibrations
 

Hello,

I am new to boating. But have been worked on a few car engines. If it is a rod it does usually happen at a specific RPM like you explained. quick way to tell is pull the dip stick the oil will have a metal flake in it like a nice flake paint job.

Good luck
Rick