Tuesday, April 30, 2024

M25XP Damper Plate replacement Pt.3

 Day 2 - Engine disconnection

Continuing with the engine disconnection process on Day 2.

Again, we limited out time at the boat to 3 hours and only just went over that limit, however, we got a lot done.

Removed the Alternator. That involved removing the Serpentine belt and disconnecting the +ve lead that connects the Alternator to the Main ( LiFePo4 ) batteries. I shut the Solar system down and then turned the master battery switch to off, disconnected the alternator cables, insulated the Main +ve lead and then turn be master battery switch on and then the Solar breaker. Also detached the Alternator Temperature sensor from the -ve connection.

Detached the Exhaust. It just took a gentle tap with a flat head screw driver and the exhaust easily parted from the exhaust manifold.

Detach the fuel hoses: Mindful that they would be full of diesel fuel, we had a disposable cup handy. The hose clamps that secure the hoses to the Primary Fuel Filter housing and the hose from the Injector return fitting were badly damaged by poor quality hose clamps, the perforations have left extremely deep cuts into the hose rubber. I'll replace them with embossed hose clamps when I put the engine back in place.

Detach the engine ground wire from the bell housing. It is held in place by one of the bolts that connect the bell housing to the backplate of the engine.

Detach the Coolant Thermostat temperature sensor and alarm from their housing.

Detach the Starter motor & Solenoid. This involves removing the starter cable ( which connects to the Stater battery ) The Solenoid cable There's also the cable that was used for the original 'Amp' meter on the control panel. It was easy to remove the two bolts that secure the starter by using two socket extensions to reach from in front of the engine back to the starter bolts.

Detach the Oil pressure switch connection. Easy using a short screwdriver.

Detach the Glow Plug power connection.

That pretty much detached everything that needs to be off in order to lift the engine.

My plan for the next part is to lift the engine out of it's normal position and move it forwards so that it can be rotated in order to work on removing the Bell housing. That will provide access the flywheel and the Damper Plate - the reason for doing all of this.

While the engine is out, I'll take the time to service the exterior of the engine, clean it up and apply some fresh engine paint. I'll also replace the primary fuel filter.

Not working on the boat tomorrow ( Wednesday 5/1/2024 )
Plan for Thursday: Protect the floor in front of the engine bay ( I know, that's pushing the concept of 'Engine Bay' :) ). I'll build a temporary engine mount in order to lower the engine. I'll use a simple 4"x4" beam with an additional piece of 4"x4" just bigger than the engine mounts.

That should provide plenty of room to get around the engine but also, it should allow me to remove the chain hoist used to lift the engine so that I can get out of the boat via the companionway.

I'll make the beam tomorrow ( Wednesday )

M25XP Damper Plate replacement Pt.2

The Plan for changing the Damper Plate

Today ( Monday April 29th ) we went down to the boat with the intent on figuring what and when we will work upon. I spent a few minutes reviewing the engine and making the plan. I'm only going to work for 3 hours each day, no point in exhausting myself and will make better progress too.

Remove the Heat Exchanger. That's 4 hoses ( I should have drained the coolant before disconnecting those hoses ) and two large hose clamps that secure the heat exchanger to it's mounting plate.

Disconnect the Throttle Linkage and Engine Shutoff link from the engine. Disconnect the gear shift cable from the gear box.

Remove the 4 engine mount top nuts.

Remove the 3 bolts that hold the exhaust pipe fitting to the exhaust manifold.

Replace the gear shift cable clamp securing screws with a matching pair of nuts and bolts so that they can be easily manipulated using a wrench and rachet socket instead of trying to hold a screwdriver on one end.  Grrr. ( worse, the two screws were a mismatched one longer than the other and one a flat head screw the other a Philips head screw ) 

Remove the heat exchanger mounting plate and clean it up, it's corroded - look for the cause.

In order to remove the stud bolts that secure the exhaust fitting to the manifold, put on a second nut and lock with the one already on the bolt, then use a wrench to unscrew the stud.

Change the Zink on the heat exchanger while it's out.

Plan for Day 2: 

Remove the Alternator, disconnect and isolate the power cable, disconnect the alternator field connection plug. Disconnect the grounding cable from the engine block and disconnect the prop.





Monday, April 29, 2024

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.