M25XP Damper Plate replacement

Replacing the Damper Plate on our Universal M25XP engine.

After replacing the Engine Motor Mounts on Eximius' Engine, the noises from the engine also changed. I spent several hours working on the Alignment of  the engine to the Prop-Shaft, the noise from the engine at about 1200-1400 RPM was not normal. The propulsion system has always had a sweet spot throttle setting where the vibrations were minimum but now the sound was so bad that I would not feel comfortable even motoring to the end of the canal.

I called a buddy that had told me of a similar situation on  his boat a year or so ago and he graciously gave me the contact info of the mechanic that solved his issue ( alignment ).

When I called 'Greg' he responded that he could meet me at the boat at 11:00 today, WOW! anyone in South Florida knows that if a boat mechanic responds like that then you get your butt in gear!

Greg was at the dock before me and I was early - this is a really good sign.

Once aboard, we discussed previous work I have done on the engine:- Replaced the motor mounts 8 years ago, had the Injector pump rebuilt by RPM a local company, new injectors at the same time and new fuel lines from the pump to the injectors, replaced the Alternator and installed a Serpentine Belt system and External Alternator Regulator, installed a PYI PSS ( shaft seal ) and done an engine alignment, Oil and Filter changes every 50 hours of engine run time. Completely new control panel engine harness wiring.

It was time to flash up the engine. I opened the raw water thru hull valve and heated the Glow Plugs and Started the engine - she started right away.

Greg had me change the throttle settings and gear shift position a few times and increasing the RPM until the noise occurred. During this time, Greg watched the engine and felt various parts giving the engine a lot of attention.

The good news. His opinion of the engine was positive, no excessive vibration but the noise was definitely an issue that should be dealt with promptly. Greg discussed the consequence of the 'Damper Plate' failing and how it could do significant damage to the engine &/OR gearbox. So, I'm on it.

Greg provided me with the contact of a local company that probably has the Damper Plate in stock. 

We shared a few stories about our similar backgrounds in the Navy aboard Aircraft Carriers, his time aboard ending before mine began in 1964. 

I called the company and found that they do have 3 types of damper plate in stock and the best thing to do was to bring the plate from the boat to them and they would confirm which one to use.

Greg advised that the Damper Plate should probably replaced every 1500 hours. Eximius has about 7,000 hours and is 37 years old, that comes down to about 200 hours a year. We do that easily! probably more.

So, we're going to replace the Damper Plate.