Is my Diesel Mechanic brilliant or a fool?

[fritz3000g]

Here's a summary of what I've learned through this thread, and conversations with my mechanic.

1. Proactive maintenance is key. This includes:
- Check engine oil, gearbox oil, fuel filter, the pan (for leaks), belt tightness, and seawater discharge every day I'm running.
- Replace fuel filters, oil filter and impeller, annually.
- Adjust idle speed annually.
- Keep fuel tank full, add diesel stabilizer if you're not going to use up the fuel in 9 months, and drain the fuel tank when the fuel filter starts to show crud.
- Replace belts, hoses, and exhaust parts when they begin to show wear.

2. There are ways to determine whether the engine is beginning to degrade.
- Unable to reach max rpms both under load and not under load (if issues are only under load, it could indicate an issue outside the engine)
- Smoke coming out of the tailpipe, besides immediately after starting in cold weather
- Slow starting.
- Sending for an oil analysis with Blackstone.
- Compression testing (mechanic doesn't think this is necessary, but service manual suggests it every year)

3. My engine will stall at inconvenient times, so
- Purchase a backup motor and a setup for mounting and running it while on the water
- Purchase spare parts and keep on boat:
-- Oil filters
-- Fuel filters
-- Impeller and gasket
-- Air filter
-- Belts
-- Zincs
-- Oil (same for engine and gearbox)

4. When my engine begins to degrade, consider preparing for a replacement:
- Watch for a good deal on a used engine with good compression or suitable for a rebuild.
- Start researching electric drive solutions.

5. Modify the engine compartment for ease of access.

6. Consider installing a cooling water line filter.

7. Don't worry. Just follow the list and you'll be fine.

In addition, if you're running a boat in salt water, consider flushing with a muriatic acid mix every couple of years.

Anything I missed?

[JD-MDR]

A0BAEE3F-DC3E-465D-9812-2C229C8AF926.jpeg

I installed this access plate today on my fuel tank. I can now clean my tank better and easier

[Jim Walsh]

A0BAEE3F-DC3E-465D-9812-2C229C8AF926.jpeg

I installed this access plate today on my fuel tank. I can now clean my tank better and easier

Nice work and a great improvement.

[gonesail]

those plates are the best (IMHO) and so easy to work with. plus they can be removed if you ever install a new tank. also in my experience the folks at seabuilt are great to work with.

[fritz3000g]

After running several times over the past month, the engine is great! It starts almost instantly and runs nicely. The only weird issue is that it only reaches 2500 RPMs at full throttle. However, at 2500 RPMs (and pulling a dinghy) I can get it up to 6 knots of speed on flat water. That seems odd to me, and makes me wonder if the tachometer is misreading because 6 knots with a 6 HP is more than I was expecting.

It took a bit to get it going because whoever winterized it disconnected the starter (wires hidden behind alternator) and left the water drain open. They also left the starter terminals uncovered, causing my wrench to ground-fault when tightening the belt. The wrench got really hot, the engine moderately hot, but everything was fine afterwards (phew!).

[wikakaru]

After running several times over the past month, the engine is great! It starts almost instantly and runs nicely. The only weird issue is that it only reaches 2500 RPMs at full throttle. However, at 2500 RPMs (and pulling a dinghy) I can get it up to 6 knots of speed on flat water. That seems odd to me, and makes me wonder if the tachometer is misreading because 6 knots with a 6 HP is more than I was expecting.

It took a bit to get it going because whoever winterized it disconnected the starter (wires hidden behind alternator) and left the water drain open. They also left the starter terminals uncovered, causing my wrench to ground-fault when tightening the belt. The wrench got really hot, the engine moderately hot, but everything was fine afterwards (phew!).

It could be the RPM gauge is wrong, or it could be the prop is over-pitched.

RPM is output from the alternator, so if you have changed the alternator or the size of the pulleys it could read differently. There are a number of smart phone apps that purport to be able to tell engine RPM by sound and a few that use the phone's flash as a stroboscopic tachometer. I've never tried any of them, but it might be worth a try If you suspect the RPM meter is off. Or you can find a mechanic with a proper stroboscopic tachometer and have him check it.

If the tach is correct and the engine really isn't reaching the RPM it should, your prop is probably over-pitched or too large for the boat. Other symptoms of prop over-pitching include engine overheating at high revs, black exhaust, and black transom moustache.

Smooth sailing,

Jim