Engine seems to start but rolls to a stop

[JustinT]

I've unbent a pushrod and that went ok. The others are nice and straight.

I've got new zincs on order.

Shaft anode near the prop and one on the hull.

[JustinT]

Originally Posted by JustinT

Thanks If I'd followed your advice 2 years ago

Actually, now that I have the head in bits I can see a lot of carbon and muck on the working valves and exhaust.

Clearly the engine was compromised on the stuck side long before I got the yacht. Now I'm all excited to have it all working again on two cylinders!

I actually had the injectors serviced before all this happened. They said one of the injectors was in a bad way. I'm thinking that was the failed side and that the engine had been working harder on the other side for sometime.

[Wotname]

Originally Posted by JustinT

I've unbent a pushrod and that went ok. The others are nice and straight.

I've got new zincs on order.

Shaft anode near the prop and one on the hull.

Good news about the pushrod.

There is a critical zinc rod mounted in cooling jacket of the crankcase. It needs replacing regularly; refer to page O-9 of the service manual for details.

[GrowleyMonster]

Originally Posted by JustinT

I've unbent a pushrod and that went ok. The others are nice and straight.

I've got new zincs on order.

Shaft anode near the prop and one on the hull.

Shaft and hull zincs are indeed essential, but they do not protect the engine itself nearly as well as one actually in the cooling system of the engine. There should be one, and I am almost certain that it is done for, and needs replacing. If there is none, you need to install one where it is closely bonded to the block and in the flow of the cooling water. Consult your manual for location. No responsible manufacturer or marinizer would sell a raw water cooled engine without a zinc or two.

[JustinT]

Originally Posted by Wotname

There is a critical zinc rod mounted in cooling jacket of the crankcase. It needs replacing regularly; refer to page O-9 of the service manual for details.

Ah, I see, yes. Thanks for that.

[GrowleyMonster]

Originally Posted by JustinT

Thanks If I'd followed your advice 2 years ago

Actually, now that I have the head in bits I can see a lot of carbon and muck on the working valves and exhaust.

Clearly the engine was compromised on the stuck side long before I got the yacht. Now I'm all excited to have it all working again on two cylinders!

Imagine now if you will, how much nastier your engine is in the lower works.

[JustinT]

I just looked at what was left of the head gasket and see there are metal o-rings. I assume I need to order some of those as all is destroyed. The head gasket is on the way in the post.
Other than that is cylinders look great, very nice, I see no cracking or splits. Really looks pretty good. Bit of cleaning and that looks good to go.
Indeed, something worse could be lurking under that.

[GrowleyMonster]

Originally Posted by JustinT

I just looked at what was left of the head gasket and see there are metal o-rings. I assume I need to order some of those as all is destroyed. The head gasket is on the way in the post.
Other than that is cylinders look great, very nice, I see no cracking or splits. Really looks pretty good. Bit of cleaning and that looks good to go.
Indeed, something worse could be lurking under that.

Just to be certain, get yourself a vernier caliper, a metal not plastic one, and measure the maximum height that each piston rises at TDC. A difference between them of more than a few thousandths indicates a possible problem, maybe a serious one. It's probably fine, but simple to check. A vernier caliper is like the poor cousin to the micrometer.

Like this one.
https://www.amazon.com/Stainless-Mic.../dp/B074HZ8S21

Don't get a digital one. The batteries will run down or leak. A proper mechanical one will always be ready for use even years later. A micrometer is better but this is good enough. Learn how to use it well, and you can measure a lot of stuff with a pretty good level of accuracy.

Trust me. There IS a LOT WORSE lurking down below. It will traumatize you to see it, and scar you for life. However, all the fudgy sludgy goopy stuff should stay more or less harmlessly in the bottom of the oil pan unless disturbed, but give some thought to pulling up the engine and at least cleaning out the oil pan. Crap elsewhere in the engine will get cleaned out through normal filtration and oil changes as time goes by.

[GrowleyMonster]

If you don't have a manual yet, here is a good link for downloading the entire 300-odd page shop manual, which is what you need.

https://www.manualslib.com/download/...Bukh-Dv10.html

[GrowleyMonster]

Originally Posted by JustinT

I just looked at what was left of the head gasket and see there are metal o-rings. I assume I need to order some of those as all is destroyed. The head gasket is on the way in the post.
Other than that is cylinders look great, very nice, I see no cracking or splits. Really looks pretty good. Bit of cleaning and that looks good to go.
Indeed, something worse could be lurking under that.

If the rings are flat, I suspect that they are part of the head gasket. I believe the old ones had metallic rings built in but now the new aftermarket ones use gasket material with a sheet of steel as a core and fiberboard cladding top and bottom.

[JustinT]

Thanks for the info Growley.
Here is a video of the moving exhast valve: https://youtube.com/shorts/R8PwwUk9I...6Zzw8YmlJvXwVU

[JustinT]

There is an "oil feed pipe to rockers" mine is squashed. Is that a "part" or just a piece of fashioned pipe? I can't find it online as a part.

[jamhass]

You or a shop might be able to cut the pipe from the end fittings and silver solder a new pipe shaped to fit the original if you can't find a replacement.

[skipperpete]

It might be squashed by design to restrict the oil flow, the rocker gear requires very little oil. Unless its completely blocked perhaps leave it as it is.

[GrowleyMonster]

Originally Posted by skipperpete

It might be squashed by design to restrict the oil flow, the rocker gear requires very little oil. Unless its completely blocked perhaps leave it as it is.

That sounds logical, Pete.

Justin, can you blow air through it? And does it seem to not be cracked?